Everyone has to get old some time. But what if at least for some aspects of Aging we didn't have to imagine if the loss of heart size and the stiffness that often comes with aging could be reversed even well into late middle age and not by a little by a lot today's guest. Dr. Benjamin Levine has shown that with the right exercise protocol people who are sedentary. Most of their lives could reverse up to 20 years of heart aging. Dr. Levine is one of the world's leading experts in understanding how
How the heart adapts under a variety of conditions whether that's exercise Elite athleticism or hospital bed rest or even highly exotic conditions, like prolonged exposure to microgravity. He is the founding director of The Institute for exercise and environmental medicine at UT Southwestern in Dallas, a leading facility renowned for his research in cardiovascular physiology his expertise also extends into space medicine where he advises NASA underscoring his broad deeply
Understanding of how the heart changes over time additionally. He is a recognized Authority in sports Cardiology Consulting for organizations such as the NCAA and NFL NHL and various professional sports leagues, the implications of being able to reverse any aspect of Aging are immense, but the key ingredient truly is committing to the process doing the routine sometimes boring stuff day in and day out and sometimes embracing a little
challenge to dr. Levine's research highlights the importance of ongoing commitment. It is one of his Landmark trials that he is his team showed that participants who had been sedentary for most of their lives put them on a structured graduated training regimen this program culminated in five to six hours of physical activity per week sustained over two years participants engage in a variety of exercises ranging from high intensity interval training session.
Like the Norwegian 4x4 to light aerobic activity on recovery days and strength training the results were remarkable demonstrating that it is possible to reverse significant aspects of heart aging with the right commitment and exercise protocol. But let's suppose for a moment. Our goal isn't just to bail ourselves out at the absolute last minute with some type of Herculean effort and instead we ask ourselves. What we should have been doing all along. What is the right routine to a
Age best from the start. Dr. Levine's research also looked retrospectively at the hearts of individuals based on their self-reported activity levels over 25 years. It was the committed exercisers alone those who consistently exercise at least four to five days per week who saw significant benefits in staving off the gradual increase in cardiac stiffening and heart shrinkage seen later in life this highlights the importance of exercise as part of your personal hygiene and provides.
Insight into how much we should be exercising throughout our life to maintain heart health. However, as we push the boundaries of what our bodies can handle some Studies have raised concerns about the potential risk associated with extreme exercise such as high levels of coronary artery calcification seen in marathon runners and a greater risk of heart arrhythmia known as atrial fibrillation in veteran endurance athletes today. Dr. Levine will help us explore the balance between
oil and potentially risky physical activities clarifying how intense exercise regimens might influence heart health differently and what this means for those who regularly engage in high endurance activities we delve into whether this stabilization of plaque through an exercise and intense exercise translates to lower risk of cardiovascular events, despite. The higher calcification levels often reported in this episode. Dr. Levine and I also discuss why three weeks of bed rest produces.
Functional decline that is actually worse for Fitness than 30 years of aging and also how bedrest affects the size of the heart mimicking aging how to make exercise a part of your personal hygiene and some of dr. Levine's key insights on how to do that best. He's ultimate prescription for Life blending resistance aerobic endurance training and more conventional programming like CrossFit into one package to maintain a youthful heart even into older age whether CrossFit counts as adjourn and
Ernst training resistance training or both why pure strength trainer should incorporate endurance training and vice versa. The number one sign your overtrained. Dr. Levine's activity recommendations for Recovery days practical lifestyle protocols for lowering blood pressure why you shouldn't become an endurance athlete just to live longer and so much more as a companion to this episode. We've prepared a thorough guide on omega-3 supplementation that I think will be invaluable for
We're looking to understand this complex topic more deeply IT addresses the substantial benefits of Omega-3s for cardiovascular health confirmed by numerous randomized controlled trials and it also tackles the nuances and potential risks specifically the recent discussions around Omega 3s and atrial fibrillation in the guide. You'll find a rigorous examination of what makes a quality omega-3 supplement factors, like Purity freshness the bioavailability of different forms and dosing strategies that can elevate your omega-3 in.
Dex to a level linked through observational trials with the significant increase in life expectancy. We also provide a critical analysis of some of the top omega-3 supplement Brands evaluating them based on their performance in third-party testing to ensure you're choosing the most effective and safest options available. I highly recommend downloading this guide. It's available for free at FMF omega-3 guide.com. Once again, that's FMF.
Omega-3 guide.com now, let's get on to the core of today's discussion how exercise prevents and reverses aspects of heart aging with dr. Been. Lovin.
I'm so excited to have you here, dr. Levine and there's many many things that I really can't wait to talk about with you today. But maybe we can start with bed rest and the effects of bed rest on cardiovascular health. So you were part of one of a very I would say famous and informative studies the Dallas bedrest study.
Yeah, so actually I was only 10 years old when that study was first done. So my part arrived much later. Thank you for that very generous.
This introduction but you know, the cardiovascular Community used to put people to bed after heart attacks or things like that. That was the standard of care and in the mid-1960s my mentors in Dallas Jerry Mitchell Gunner Blomquist and banks old teen some of the most famous cardiovascular physiologist ever took five young men and put them to bed for three weeks and then train them for two months and frankly almost everything we've learned about the cardiovascular adaptation.
To changes in physical activity began with that study only five guys. And so like I said, I was only 10 years old. So I didn't participate in that study. But 30 years later we found those same five guys and brought him back to Dallas to study them and to compare the effects of 30 years of Aging with what happened to them during bed rest and quite remarkably not a single person. Not one was in worse shape after.
Our 30 years of Aging then they were after three weeks of bed rest when they were in their 20s. So three weeks our bed rest was worse for the body's ability to do physical work than 30 years of aging and that that observation really started us on a whole series of studies trying to understand what's the difference between a sedentary Behavior or or lying in bed or being physically inactive and
Aging So when you say that the 30 years of Aging was no worse than three weeks of bed rest in terms of so what sort of physiological parameters you talking about.
These were the five most studied humans in the history of the world in terms of all the studies that were done to them. But the sort of simplest is the maximal oxygen uptake. That's the maximum amount of oxygen that can be taken in from the environment brought into the body by the lungs.
R2 by the heart to the skeletal muscle and used to do physical work. It's the exercise physiologist marker of fitness. And so when we hear the term cardiorespiratory Fitness, that's what we really mean and there are ways to estimate it there are ways to measure it directly many of your audience will have seen or even participated had a mouthpiece in their mouth and run on a treadmill till they can't go anymore and that's how you measure the maximal oxygen uptake.
Back in the 1960s. They did a lot of other things you should see the pictures of these guys. Their catheter is in the arms catheter is in the bladder catheter is everywhere. They measured heart thighs there wasn't echocardiography then so they measured heart size by x-ray. Now that takes that takes into account both the mass the muscle mass of the heart and it's volume and the heart just shrunk in bed rest. So the heart shrinks the muscles atrophy.
and that's probably the single most important thing that happens at least to the heart the blood vessels adapt to to meet the demands that's placed arms or the blood vessels kind of get a little smaller also everything kind of contracts and that's probably if I had to pick one thing that would be the archetype of the bed rest is the shrinking and atrophy of the circulation including the
heart and you said that you you that they were
And after bed rest, so yes, was this reversible? Well,
that's really interesting. Right? Because out of those Five Guys three of them were just Average Joe's now they weren't athletic. They weren't sick. They were just healthy college students two of them were competitive athletes one was a semi-pro football player and the other was a distance Runner they all decreased by about the same amount they lost Fitness, but what was really interesting?
Is that the three guys who were relatively unfit quickly return to Baseline and even got fitter than they were before hand for the fitter people. It took them the full two months to get back and even then they weren't quite back at where they were. So so people whose bodies are adapted and trained they lose the same amount but it may take them longer to get back and part of that may have to do with the load. That's
Placed on them. So it's you have to kind of build back up slowly after you've been in bed for a while and it just takes people forget how much load they placed on themselves to get them back trained and you can't just pop into that all of a sudden you've got to build up slowly when you've been in bed, and we've learned a lot about this in the covid pandemic where where people you know went to bed and we'll placed in quarantine and lost a lot of Fitness. I will tell you to me.
Me one of the most compelling observations is what in sticking with the covid pandemic for a minute because really is the same concept. So you've heard about long covid for example, and people who have symptoms that last more than three months 12 weeks after their covid infection. Well, you know, we were very worried when the covid pandemic head about what was going to happen to the athletes because we were worried that they were going to get infected. We know that covid could infect the heart we worried it was going to cause sudden death
and so we were very intensely monitoring all the Collegiate athletes and out of hundreds. If not thousands of Collegiate athletes who had covid and went through brief quarantine. How many do you think had symptoms that lasted more than 12 weeks 1600 and bread pedak study.
What percentage do you think make a guess 8% Yep, 0.06 percent to people to out of 1600. Why is that it's not that athletes are resistant to Long covet. No, it's because as soon as they got over their quarantine period because they were in a competitive environment, they quickly returned to a
trainer
monitored and
wanted return to play program. So it's really important as sued for for almost any condition as soon as that forces you to bed that you have to get up and start moving and progress your training to return to a your Baseline State and some cases you can do even better.
So as the is the the hypothesis that after after being let's say it's a encodes case like exercise.
Is may help protect against having this long covid.
Absolutely now, you know, let me caveat that by saying some people have been get really sick with covid right and covid can affect the heart and the lungs and the mitochondria in the muscles in the brain. They're all sorts of things Legions of things. They can they can be injured by the body with covid. So we're not talking about those people right? Because that's a whole different story where we're talking about people about people who didn't get that sick.
Sick and had to be placed in quarantine or which often resulted. If not in Frank bed rest at least dramatic reductions in their physical activity. Well, the other thing that is that there was a lot of Public Health messages that were urging people not to exercise. I know I know he because it was somehow I don't even know exactly where that was coming from, but it was potentially dangerous. Well, that's what we were worried about with the athletes right that because we would check there for
Check them for a troponin, which is a marker of cardiovascular injury. We do echocardiograms. We check electrocardiogram that was called the Triad. You know, I was part of the sports Cardiology Council that laid out those guidelines of the the covid Triad testing what we learned since is that that really wasn't that effective unless the individual the athletes had cardio pulmonary symptoms.
If they had palpitations or exertional shortness of breath or chest pain, those are the people who really needed more intensive evaluation to make sure that they are bodies their hearts and their lungs are not been injured by covid we then went on to do cardiac MRI is in a lot of people a
lot of athletes who
had abnormalities in this Triad and if they didn't have cardio pulmonary symptoms, they didn't have anything wrong with their heart. So so we we were deathly afraid of this because you know,
Example in the military the most common cause of sudden cardiac death during basic training is myocarditis. That's an inflammatory infection of the heart muscle by a virus and that remains and persists as a diagnosis as a cause of sudden cardiac arrest in young athletes. So once this covid pandemic store again, we realized that it affected the heart we said, oh my God, you know though the streets and playing fields are going to be
Littered with the dead bodies of young athletes fortunately that was not the case, but we were worried about it and I think it generated tons of Publications and guidelines and things like that and we learned a lot from it, you know, it gets us back to this bed rest model that you had started talking about in the original Dallas bed rest and training studies. Would we put people to bed for three weeks and a lot of our high resolution physiology experiments have used that kind of two to three-week model.
The because at least in the in the early 90s, that was what we were doing in space flight right bed rest is a model for spaceflight because you remove the head to foot gravitational gradient. So from head to feet there is no gravity so that it's very expensive to do work in space. So we use bed rest as that model but we put people too bad for a longer time than that. We've put people with de bad for two weeks six weeks even 12 weeks of bed
rest, and this is like literally bedrest like we're not getting up you can't
Even get up to
use the toilet that's we're talking strict bed rest and and that you know that takes a little practice for people by the way.
So so how much of I mean it is this bed rest a almost accelerated aging model and and how much of cardiac aging what is cardiac aging how much is due to being
sedentary? That's the million-dollar question, isn't it? We found that the heart loses about 1% of its muscle mass a week.
In bed so it just when we monitor people for 12 weeks, so I just got smaller and smaller and smaller now obviously, it can't get continue to atrophy forever. And we've sort of used spinal cord injury as a model for what that Plateau is. You know, how low can you go and it's about 25% so patients with spinal cord injuries have about a 25% reduction in the mass of the heart. We see the same things in young women with
the disease called pots or the postural orthostatic. Tachycardia syndrome. We can talk more about that later. If you want. I know that's not your Prime Focus if we take people on and look either cross-sectionally if we train them we can see, you know, at least day 15 to 20 percent increase in the size of the heart and if we look cross-sectionally comparing Elite Runners to spinal cord injury, it's a 75 percent change in cardiac muscle mass.
Is adaptable plastic responsible responsive to changes in physical activity. So, you know, we asked just the question that you asked Rhonda how much of what we see with normal healthy aging is due to becoming secretary. What are the first studies we then did to follow up on the Dallas bed wrestling training follow-up study was we went out and recruited a group of extremely healthy, but sedentary older people it's not
So easy to do by the way, you know, these are people who had no chronic medical problems. We're taking no medications except for perhaps cholesterol-lowering medication, but just didn't do any regular physical activity and we compared them to a group of elite Masters athletes. These were individuals who trained virtually every day for much of their adult lives, and we're competitive at the regional and National level and
we use a technique that we developed in my laboratory Tiff estimate and to quantify the let's call it the flexibility or stretchiness of the hearts muscle the medical term is compliance, but it's really how much will the heart stretch and we all think about aging, you know, you think about aging of the skin for example, right that it becomes less stretchy, you know, it can stiffer and and then LG I like to give people
people as with a nice brand new rubber band right take it out of the box stretches stretches great right stick it in your junk drawer, right and come back 20 years later and take it out of the drawer and try to stretch it again. It doesn't really stretch. It loses that stretchiness and there are a number of specific biological reasons why that might be and we can talk about that. But but that becomes a really good marker of the for the cardiovascular system the compliance or
the bility of the heart to stretch and accommodate blood not just a heart but the blood vessels also is a marker of the youthful cardiovascular structure. So we stick a catheter in the heart. We put it in through a vein in the arm.
We then unload the heart. We reduce its volume by using a procedure called lower body negative pressure. Basically, you put someone in a box sealed at the level of the hips hook it up to a vacuum cleaner and suck and we can literally pull all the blood out of the heart so we can make the heart smaller and measure the pressure and it's volume using a good choreography. Then we give them a volume load. We put an IV in and we blast salt water into the heart and we make it.
Bigger as big as we can get it and then we look at the slope the the stretchiness of the heart and what we found is that when we compared the seniors to the healthy young individuals, we notice that not only did the heart shrink, but it's stiffened right? And then when we sit we looked at the elite athletes
Their hearts were indistinguishable from healthy 30 year olds. So a lifetime of endurance training at a level commensurate with being a competitive athlete was sufficient to prevent that aspect of cardiovascular aging now that's really interesting from a physiological perspective, but it's not a very good Public Health measure, right? We can't really expect everybody to be a competitor Masters athlete. So the next question we asked was okay.
Um, where were how much exercise does someone need to do over a lifetime to preserve their youthful cardiovascular structure? So we turn to our colleagues at the Cooper Clinic and we partner with them Cooper Clinic is a is a center in Dallas developed by Ken Cooper where they have tracked physical activity and physical fitness for 40 40 years. I mean
Ken was very prescient and starting that database and we've learned a lot from that and looking at people and tracking their Fitness in their physical activity over a very long time. And we said, okay, we want you to help us find people who over 25 years and multiple visits to the Cooper Clinic have said on their questionnaire. Yeah. I do know regular exercise and we call those people sedentary and we would allow so to less than two days.
A week of regular physical activity sedentary then we took people. Okay who did two to three days a week consistently over their lifetime. We call that casual exercise training. Then we looked at people who did four to five days a week. We call that committed training and then a whole nother group of Masters athletes who are called competitive training and when we did the same techniques, we measured their heart compliance and their vascular compliance.
And lo and behold two to three days of exercise over lifetime had no effect at all. It did not protect against that aging effect four to five days a week got us most of the way there close to the competitive athletes. Not exactly the same not all the way there, but pretty close so that gave us the sense that the optimal dose if you will a physical activity is four to five days a week over a lifetime making it's
Be part of your personal hygiene, we can talk about that a little bit later because then the next question we had to ask bless. All right, we studied our masters athletes and our healthy sedentary people at age 70 and our youthful people were at age 30. So when in the aging process does this begin right? So we partnered with a Dallas heart study a large community based very highly intensive.
Eric study and we looked at people who were in their 30s in their 40s and their 50s in their 60s and their 70s and we did the same studies on them. And what we found is that the heart starts to shrink in that late middle age period you know if you think about aging at so late middle age is kind of that 5265 period Early Middle Ages have 35
I have 250 range. So the heart will get a little bit stiffer but it's in that late middle range. It starts to atrophy and get really you can see the most dramatic effects of Aging. So we said, okay. Well if this all reversible that was sort of the question you asked me earlier and so we took our healthy seniors and we train them for a year. We used the same training program.
That we used in a group of young people trying to make them endurance athletes. Will I know you want to chat about that a little bit also, but we put them we train them hard and they got fitter for sure but we didn't change their heart structure at all. Not even a little bit. So once you got to be age 70, it was virtually impossible to change the heart structure. That was very disappointing because we really thought we were
we were going to be able to reverse it. And when we trained our young people, we sort of very marked and very impressive increases cardiac size and come compliance and things like that. But we said, okay what if we made a mistake what if we started too late and what if we didn't train them long enough and what if we didn't train them hard enough?
So he then said okay, let's take a group of those late middle age errs, and The Sweet Spot. Let's train them hard trade him increasingly fit over a year and then sustain that at our perfect dose that four to five days a week and we'll do that for two years.
And lo and behold we were able to reverse the effects of sedentary aging by sustained training at the right dose at the right time period in the aging process so that that paper which was published in circulation. Got a lot of press it still is that among the top ten papers for something called out metrics, which is the interest within the media and the public and the
professional Community the top 10 in the history of circulation, which is American Horse Association Journal
incredible. How much would you say the heart aging was you know reversed in these mid
late middle age 50 year olds. Yeah 50 year olds. So the answer to that is from the standpoint of the youthfulness the compliance of the heart most of it so we didn't get quite back to being a healthy.
Real but we got pretty close. So, you know, there are a lot of other things that happen with aging that are not just related to the to the sedentary - of the circulation, of course, you know, one of the things that happens is you get accumulation of advanced glycation end products. You know, what those are those are yeah. So those are the things that not you run that but other people stiffen the your skin and make cause wrinkles.
We measure it in diabetics with hemoglobin A1c. It's a natural biologic chemical reaction called the maillard reaction. Your audience is probably more familiar with it from basting a turkey or what do you think causes the crinkling and stiffening of the skin when you baste a turkey it's it's this reaction this complexing of glucose sugars with carbohydrate with collagen and it happens in the skin and happens in the blood vessels it happen.
The heart so we actually gave a drug which doesn't exist anymore. I have the last of it in my laboratory that breaks Advanced glycation end products and we gave it to another group of healthy sedentary seniors and one group just got the advanced glycation end product inhibitor one group got a placebo another group did a year of training just training and another group did the advanced glycation.
And product and training so for groups.
Just taking the advanced glycation end product inhibitor didn't do anything. It worked in animals. We saw a marked improvement in rats. Nobody really cares that much about that. But because we're not rats, but it didn't it didn't help the center humans. And once again, we saw that a year of training didn't do anything, but when we added the training and the advanced glycation end-products inhibitor, we have the equivalent of about a 15-year reduction.
In the apparent vascular age of the circulation in seven year olds in 70 year olds. That's
right. So the advanced glycation end products. It's interesting because it's very as you mentioned tied to blood glucose regulation. And of course people with type 2 diabetes are the extreme case where your type one as well like they're not able to regulate their blood glucose and have probably the most risk of having higher levels of bands Caucasian and products and you know vascular damage, but
So you mentioned the the heart aging and you talked about before I don't know if you started with what when this starts but the stiffening you said it is stiffening until about middle-aged and then it starts to shrink. That is that correct? That's right. So the question is it's interesting that you were able to reverse this, you know cardiac Aging in these, you know late late middle age both crying.
Yeah, like, you know, so 50 to 65
Our late middle age Target.
So you're already stiffening the blood vessels at that
point. Yeah, you're probably having some stiffening. That's exactly right. It's not fully ensconced, you know, it's still reversible by then. So, okay. So the question is would be interesting to see if there were like a subset of people to that. Let's say had low very low HP 1 A 1 C or something that did respond. I know it's a good question Rhonda and you know if you think about it he
The globin which is what we're talking about when we measure hemoglobin A1c that you know last for 120 days, right? It doesn't those red cells don't last forever. Right? So so the that's why hemoglobin A1c is such a good marker of diabetic control blood glucose is measuring your glucose instantaneously. Hemoglobin A1c is measuring the average over the last few months because that's how low hemoglobin levels.
Ests but College in last forever. So once you've glycated it's done and that's why you know measuring glycated hemoglobin products in the skin or in the vasculature is a marker of something over an even longer time scale. You know, we we hoped to be able to break all those to be honest with you. I'm not sure that we did the animal data is very compelling. We did not actually take
cardiac biopsies to prove that we had broken the advanced glycation end products, right? We just use the physiological consequence and so one could argue that we didn't even do what we thought we did. But I think I was impressed Enough by the combination of exercise training and breaking the AG ease of use that acronym for Simplicity sake that I do think it plays.
Some roll it's obviously not the entire issue, right because just breaking them by themselves didn't do anything but the combination of the stretching of the blood vessels and the Heart during exercise is perhaps enhanced or was perhaps enhanced by breaking the advanced glycation end products.
So what would you say to someone who's in their 70s? It's been sedentary and wants to train for
five days a week and said you're talking about this two-year study. I mean and I've looked I've read the methods section 2 and it's it's a quite impressive. I mean these people are you know, they're doing a lot of physical activity and including vigorous intensity exercise, you know what they're doing, you know, very intense exercise at least once maybe twice a week. So so what would you say to someone who's in their 70s? I mean, how can they improve their cardiovascular health? So I'm not saying that we
Throw our hands up and saying oh it's too late because that's clearly not true. Right? I will say if you hope to overcome 70 years of bad behavior of bad diet and sedentary anus and smoking you can't make that up with a couple of years of exercise training when you turn 70 that being said, there are a lot of other benefits to exercise training that are not related to cardiac structure, right you improve and do filho function.
What I mean by that is the arteries have a lining inside them. That is it's not like a lead pipe. It's actually a live its biological and it allows for that smooth flow of blood to and then as you need more blood like during exercise those blood vessels start to expand so the endothelial relaxes and opens up the blood vessels and it's damaged the into
Helium with cholesterol and and hypertension and smoking over the years that causes atherosclerosis disease. So so it's a very important biologic phenomenon that is clearly improved by exercise training at any point in life. So I think that's really helpful. I think we know that exercise training Alters the autonomic control of the circulation the autonomic nervous system. Is that part of the brain?
And the nervous system that regulates those things that we don't have to think about like you're not sitting here saying what's my heart rate? Is it 60? Is it 50? How do I make it 62 that just happens in the background? Right and the autonomic nervous system has a break which is the parasympathetic nervous system. You've heard the term vagal responses and an accelerator. That's the sympathetic nervous system and you're constantly balancing brake and accelerator throughout your life during
Sir sighs you take your foot off the brake you withdraw the vagus nerve and you increase the sympathetic nerves. That's what speeds the heart rate during exercise and that comes from signals and skeletal muscle. That's how your brain knows what to do during exercise. So we know that if you is going to be a little bit. I'm going to take a step back for one second. We know that if you have an acute heart attack and if I in a dog if I tie off a coronary artery
With a little snare while they're running on the treadmill some dogs will develop ventricular fibrillation and have a cardiac arrest and they'll do it every single time and if we resuscitate them and then we put them on the treadmill and stimulate the vagus nerve to the heart and tie off the coronary. None of them have been trickling fibrillation. They don't die and if you train them
Before you type the coronary artery without even stimulating the vagus nerve you have the same effect. So the ability to increasing in Vegas tone or or or neural activity in that parasympathetic nerve may be very protective against sudden cardiac death and those things will happen even if you start training in your 70s, so and the lastly of course is people get fitter. We know I can make them fitter right I told
Sure that and that's good that's important because unfortunately with aging you get less fit, even if you're a masters athlete you get less fit. I would be a fool. If I sat here in front of you and told you that extra has training can completely prevent the aging process. I wish that it could but it doesn't but one of the most important things is that it preserves your aerobic power this vo2max. And so
Think about a cliff right and you're heading towards that Cliff with aging and that Cliff is where the maximal effort that you have in your body that you can do is what you need to do activities of daily living that's in that 32 for metabolic equivalents met is the amount of oxygen you need to just sit here quietly three and a half. Ml. So of oxygen per minute per kilogram of body mass and once you
Get to that you're really kind of in trouble right because then everything you do in life is a maximal effort. Well, if that point is here and your Masters athlete and you're up here when you're young right and you train all your life, you stay above that really? Well, if now you're unfit and you don't exercise your life and you're heading towards that Cliff. What you want to do is change that trajectory and either push it up or flatten the Curve.
Bit so that you prolong that period before you become disabled and that comes down to both endurance training and strength training because you need both of those to be able to maintain functional capacity.
I this is great. I do want to get it a little bit more into both of those the the cardiorespiratory Fitness and certain what it means for longevity, but just before a couple more questions on your intervention study exercise dose intensity. So what about people
People that let's say they're they're exercising their doing the committed exerciser right there for 25 days a week. Yeah, but they think well, I don't you know, I'm exercising frequently. I don't need to get my heart rate up to a high intensity, you know vigorous for nearly 80 85 percent max heart rate. What do you think about that is important because in your study at least in the the cheer intervention people were definitely doing vigorous intensity exercise in addition, right?
So that's
I think one of the more challenging questions to sort out right because if you were I know you were listening carefully your end reading carefully. I'm very quite impressed by how prepared you've been to come to this interview, but we only stratified people by frequency. That's two two three four to five or six to seven. We didn't stratify them based on how many interval sessions they did or how long was there long run? You know, those are factors the
Other components of dose of includes not just frequency but intensity and duration and you can imagine trying to quantify that over 25 years is kind of tough. People can tell you. Yeah, I trained Tuesdays and Thursday. I went out for a walk, you know, I did my Zumba class, but if you ask them well, how hard did you work? And what was your heart rate and Helen do you know that's a little harder to manage. So I think that there clearly are advantages to hire.
Intensity exercise there are also greater risks. So we know that that exercise by itself does transiently increase risk for anybody at any time and that's greater risk with higher intensity. Now that risk is relatively small and it depends on how fit you were to begin with. What do I mean by that? Well, you know the classic scenario is, you know, Detroit, Michigan big snowstorm, you know, the
The dad goes out. It hasn't done any exercise and needs to shovel the walk and he has his Cardiac Arrest Berry Franklin published those data many years ago and what we know from a number of studies is that that risk of exercise is dramatically higher if you're unfit, so it may go up 100 fold above background a burst of extras if you don't do anything if you're very fit it may only go up 10%
It or 20% still goes up, but it doesn't go up by that much. So maintaining Fitness reduces the consequences of intense activity, but I think that we all have bursts of exercise during our lives whether that be running up a stairs trying to catch a bus or a train running after a kid whatever and and I think that we also know that high intensity.
Retraining relatively has relative advantages over lower intensity training for improving maximal aerobic power. If you're going to ask me what is high intensity training mean that's a whole nother discussion. I know you you met with my friend Marty Kabbalah and had a discussion with him. Then he few months ago. So when I think about aerobic power, I like to think about Ian Hoffs.
Which is the old Norwegian ski team work out four minutes at 95 percent of Max followed by three minutes or recovery repeated four times. Even if you don't have a heart rate monitor on it's basically as hard as you can go for four minutes and at the end of that four minutes, you need to be ready to stop and then at the end of the three minutes of recovery, you need to be ready to go again, and that's how you judge that intensity completely independent of heart rate, and I think that if I compare
You know 30-minute moderate-intensity session versus a 30-minute 4x4. Clearly. The 4x4 will have a greater benefit on improving aerobic power session per session that being said over time. I think there are great benefits to doing more moderate intensity exercise also its lower risk. It's easier to do it's emotionally easier for many people.
Others love doing short duration burst activity they say oh my God, I can get me and I can get the same benefit by only exercising for four minutes as opposed to 40 minutes. I'll do it. So it's very individual and at the end of the day for certainly when you look at a competitive athlete no athlete does just one thing. That's why a lot of the studies in this field are a little bit artificial because as I I'm going to do only moderate intensity training there's a whole new
Burst of enthusiasm for Zone 2 training. I mean gosh I've had about ten interviews about what is Zone 2 training for your audience. Typically, that means exercising hard enough that you get a little sweat on your brow. You can still talk but you're a little short of breath and I like to tell people you can talk but you can't sing that's a good indicator of that higher level is owned to training. So the ideal
strategy then is to incorporate all kinds of training. That's what the human body is best at adapting to it doesn't really adapt very well to doing the same thing over and over and over again. You will not get fitter. If you do that. And in fact in our two-year training studies very some if you read below the lines a little bit we markedly upscale people these were completely sedentary and we work them very hard for
Year, right including multiple high-intensity sessions prolong sessions, but then we set it right. I want you to sustain that for years. So we dropped into only one interval session a week and one long session a week and we didn't increase the dose, right? We didn't increase the frequency or duration or intensity over that last year and you know what didn't get any fitter and their hearts didn't get any bigger. The only thing that got bigger was the Atria and we can chat about that.
That when we get to talking about toxicity of exercise training so the human to come back to our point the human body doesn't adapt very well to doing the same thing over and over again and so my prescription for a life if you will is one that mixes things up. So I suggest to people that you spend do at least one day of a long session that lasts at least an hour and it should be fun. I don't care what it is it could
Be you know going square dancing. It could be a long walk with your spouse or a long bike ride. It could be some other class that you take but it needs to last over an hour and at least should be fun. Second thing you need to do is do one high-intensity session a week.
I like the 4x4. I think it's very effective this great data about it from the Norwegians, but I don't care if you did Two by six or if you're a Mardi Gras ball fan if you did 30 seconds times 8, it doesn't really matter just do one thing at high intensity and then do two or three sessions of that moderate intensity at least 30 minutes getting the talk test and then supplement
meant that with one or two days of strength training and what I mean by strength training, it doesn't mean you have to go to the gym and pump iron could be Pilates. It could be Strength yoga anything that requires training of strength and skeletal muscle and if you do that over your whole life, I think that's the best strategy for preserving cardiovascular health. Now, if you tell me you want to run an Iron Man you gotta train different than that. Okay, and that's a really important.
And think for your audience to understand training for health versus training for performance, right every coach knows how to train performance. And so if that's your objective if your goal is to have a competitive performance objective, then you have to train differently. If you tell me your goal is I just want to preserve my health and stay fit and have a good life then you don't need to train.
He hours a week, but if you want to compete in Kona, you need to train 30 out 20 to 30 hours a week or you're not going to be successful. So I think you've got to discuss clearly identify what your goal of your Fitness is and your goal of your overall health and that's what will guide your training program over your life. Let me just add one more thing. I can he see the questions circling around in your head. I can't remember I'll pop will come.
To her later. So definitely a lot of questions and I'm trying to figure out where to go first. So I think the the cardiorespiratory Fitness and the vo2max and lots of questions with that starting with you talking about what your goal is, right? So do you want to be a masters athlete do you want to train for Health and Longevity? I loved the way you explained the cardiorespiratory Fitness and function how it's keeps going down with age and how you kind of want to stay above this level.
If you start way up here, you know, it's easier to kind of go down. It's going back to that same analogy like contributing to your retirement fund. Dr. Brad schoenfeld talked about this in the podcast with muscle mass and I just it applies to so many different areas and think cardiorespiratory Fitness is another one, right? If you're starting way up here then the decrease with age, you know, it's not going to be as big of a deal functionally. So why do you think cardiorespiratory Fitness does correlate with longevity? So there the higher the vo2max?
Switches marker of cardiorespiratory Fitness the lower the mortality
risk. So I'm going to remember your question. I remember what I wanted to say. So let me go back to that. Okay. So the one thing I want to say is that exercise needs to be part of your personal hygiene. It can't be something that you just add on at the end of the day when you're tired and you know, you don't really want to do it. It has to be part of your life like brushing your teeth taking a shower changing your underwear.
We're having breakfast. These are things you do to stay healthy and exercise is one of those and the mindset of people who sustained exercise over a lifetime and who are able to do this over and over again and who are able to stay fit and healthy is that it's part of their lives. It's not something they just add on right so you you brush your teeth twice a day because you don't want cavities what you exercise because you don't want cardiovascular disease, right? I mean,
It's there's other reasons your exercise to you eventually, but but yeah, I love that part of your hygiene where it's not just oh, it's this thing. I have time to warn
ya have to go do it.
Right? No, it's it. No, it's you do it. It's like just like you brush your teeth. So the vo2max and long and Longevity correlation. Why do you think vo2max correlates with
longevity? So so first of all, I think it's important to realize that that correlation is relatively weak.
Week, I mean, obviously when we're talking about the effect of aerobic power on longevity. There's a number of reasons why I think that relationship exists. First of all, if you're not sick, it's easier to exercise why I didn't preserve your aerobic power. So there is a bias associated with looking at those factors regardless of how well you try to control for them. Statistically that bias exists. There's
You can do about that. It certainly helps to be well enough to continue to train and and be fit. So if you get cardiovascular disease or cancer or neurologic disease, it's harder to sustain your Fitness. And so just be a little bit careful about that VO2 max is a function of two things. We there's a very famous equation called the thick equation which relates
02 that's the the volume or the ventilatory oxygen uptake. I started this podcast by talking about what that means but it's a function of two things the cardiac output. That's how much blood the heart can pump and the AV O2 difference the arterial venous oxygen difference, which is how much oxygen is extracted in the skeletal muscle. The cardiac output is also a function of two things heart rate and stroke volume stroke.
Time is the amount of blood that the heart can pump per beat. So the heart relaxes and when it's done relaxing, that's the end diastolic volume the time when the heart is completely relaxed at its at its biggest and then it contracts and pushes that blood out. That's the end systolic volume. Right and the difference between those two is the stroke volume. And so the stroke volume times heart rate is the cardiac output now, let's look at an example.
Elite athlete versus a sedentary person. Okay, an elite athlete can extract more oxygen than a sedentary person but you not so much more. It's not a lot more than a cinder a person and the heart rate the max heart rate of an elite athlete if anything is lower than that of a sedentary person. So the biggest difference between being sedentary and have high levels of aerobic power.
Is having a big stroke volume so having a heart that is nice and stretchable and compliant. It can relax to a large amount it let your muscles pump blood back to it and can contract strongly and vigorously and pump that blood out into the blood vessels. That is the biggest adaptation that allows you to be an elite athlete.
Well that goes back to your your you know, how exercise improves cardiac structure and function.
Because the hearts not atrophying it's getting bigger and it's not stiffening. It's be more
exact tractable. So exactly so I think that there are clear advantages into heart structure and vascular function by sending all this Blood Out and pumping large amounts of blood the in a healthy vascular system the aorta and the large blood vessels accommodate that blood it's called the wind Kessel.
It said the but when the heart pumps the blood into the aorta it expands that's why it needs to be nice and compliant and then in between heartbeats, it releases that blood into the rest of the circulation. So so that's sustained dilation is what requires a flexible arterial system as well as a flexible heart and the heart and the blood vessels are coupled together very tightly that's called ventricular arterial coupling in the physiology.
G world, but they need to be coupled and I think having a nice regular flexible aorta becomes really essential. Of course, if you've got aortic diseases Marfan syndrome, for example, genetic diseases of the blood vessels, then exercise can be quite dangerous for some of those people and the or aortic intere that's called an aortic dissection. So we know that exercise clearly does drive more blood out into the aorta.
so I think that the advantages and the reasons why High aerobic power improves mortality is it preserves vascular structure improves endothelial function optimizes autonomic tone preserves the mitochondrial function that mitochondria are those little energy-producing organelles subcellular things within your skeletal muscle within your cardiac muscle even Within
in your brain, which utilize all that oxygen so it preserves the energy-producing architecture of many of your organs and all those things are advantageous and leading to mortality now or preserving of mortality. Now, you know, you have to ask yourself what kills people right? Well one thing that kills people as cardiovascular disease and again, I wish I could tell you that exercise completely protects.
From cardiovascular disease it does not athletes get hypertension. They have high cholesterol. There are genetic effects that influence the development of cardiovascular disease. So so exercise will not provide immortality, right but it will help you manage those diseases of human life. There is some evidence that exercise can be protective against certain.
As of cancerous that that evidence has been challenged recently, but I do think the overwhelming weight of the evidence is that it reduces the risk of breast cancer and colon cancer and how it does that I can't I'm not 100% sure but I think increasing blood flow on a regular basis is beneficial and it of course by utilizing energy it helps to prevent diabetes. And if you have diabetes it helps to manage.
Diabetes it increases blood flow to the brain and has some modest effect about preventing dementia. It will not prevent you from getting Alzheimer's disease if you're genetically inclined I wish we completely understood why people get it. We don't but it certainly will reduce that risk. So I think it is a combination of the physiologic adaptations to exercise at every step of that oxygen Cascade the heart muscle the blood
Vessels that mitochondria the the sustained High rates of energy expenditure of multiple organs that help to protect and improve mortality with higher levels of Fitness. You've I'm sure seeing this this drama study in 2018 that was published and looking at cardiorespiratory Fitness and mortality and the interesting thing to me about that study wasn't so much that okay. Well if you're low cardiorespiratory Fitness you have a
Fivefold increase mortality rate over people that are more Elite. So they're in the top two three 2.3 percent of cardiorespiratory Fitness, but what was so interesting to me and again, you mentioned reverse causation. So that's obviously people that are more fit are able to exercise more with that in mind the fact that when all these other, you know diseases or negative habits were looked at for example smoking it was at least by the data and hazard.
Vo it was clearly worse to be in a low Fitness groups of the bottom 25% of the population that was looked at it was you they had a higher risk of mortality being in that low fitness group than smoking. So be a little bit careful about that for your audience what's been being would often is reported in literature is relative risk not absolute risk. So there is a protection of one compared to the other.
But for example, if being loaf, it were to be a low absolute risk, then a little bit of protection doesn't change. You know, if let's say your risk of dying in the next 10 years is 1% Okay, and I reduce that risk by 50%
1.5 Hazard ratio. I've only reduced your risk by point five percent. So the absolute benefit is relatively small so you I sent me that paper and I of course I was aware of it. It's by my good friend Dermot Feelin when he was at the Cleveland Clinic and his team there so I know the data. Well we knew about that when we put together the scientific statement for the American Heart Association suggesting the cardiorespiratory Fitness be included as a Vital sign.
You know the same thing as your blood pressure and your body weight when you go to see your doctor, you're supposed to get an A have them ask you what's your Fitness level there are ways to do that within the electronic medical record now simple Liz joy and Bob Salas when they were both presidents of the American College of sports medicine have pushed the exercise Vital sign, which is very simple. How many days a week? Do you exercise enough to get a little bit of sweat on your brow and make you a little short of breath and
And how long do you do it multiply the frequency times duration get your your physical activity Vital sign. So your doctor should be asking you that or if he isn't he or she isn't you should tell them but so when you come back down to that Cleveland Clinic study remember there are two things first of all.
These were people who were referred for exercise. Testing is were not healthy people. Okay, these are people all who had some complaint. Some of them had valvular disease. Some of them had heart disease. None of them were a fitness test on a competitive athlete and if you look at the a leak Fitness level they are nowhere near Elite the peak VO2 is in the young people was 50 MLS per kg per minute. I mean, that's
50% less than a competitive athlete at that level. So calling them Elite was a little bit disingenuous in my mind. They were the top percentage of people referred for exercise testing, but they're nowhere near a lead. They didn't these are not people doing 10 12 15 hours of exercise a week. This is 50 MLS per minute per kilogram. That's an average fit, you know, good good fit but
Good fit young person. So, you know by looking at percentages of predicted of healthy people you can get a little bit of a different perspective. So I don't think you should take the message home that you know, there's no upper limit and you can just keep on training and you'll keep getting better. I do think the message that Fitness is as important as other cardiovascular risk factors is critical and I think that's a very important.
Orton take-home message. I don't put too much stock in comparing relative risk scores. I don't think that's helpful without knowing the absolute risk data, but my friends D Blair used to say, I'd rather be fit and fat than lean and sedentary. Yes. It sounds like the the measuring your cardiorespiratory Fitness is a at the very least a good biomarker absolutely of you know your health and you know, like you said relative risk well, so you're talking about a
Rolled. Yeah, their risk of death is quite low. But when you start to get to 70, you got a 75 year old male their VO2 max that relative written that absolute risk matters more right? Because they do have a higher risk of dying from heart surgery or whatever right age related diseases. We're not going to get rid of that. Right? I can
extend the human lifespan forever. But but you're right. I think that and we made a strong case for that in the in our scientific statement. I do think
That the risk is as important as smoking and as hypertension and they have different treatments, right? So, I think the other thing to be careful about is there there's some data from the Cooper Clinic mostly but also from others Jonathan Myers at the VA in California has shown that if you if you measure Fitness at one particular point in time people who gain fitness gain an advantage,
Equivalent to people who have sustained Fitness and people who lose Fitness lose that Advantage there are much fewer studies of changes in Fitness over time as there are about a single point measure. So you have to it's the data are not as robust as what happens if you stop smoking or what happens if you treat high blood pressure or what happens if you treat high cholesterol those data are hundreds of thousands of people.
Alex really high-quality clinical trials treating these diseases so we know what the outcome is. I know less about what happens if I take a 50 year old and I train them and I increase their VO2 max by 10 or 20% What does that do to their subsequent mortality? I don't know that as well that there are data there. I think they are encouraging but they're not
As certain for example, so I know for sure that that I need to lower your blood pressure if it's too high and I think our targets are getting progressively lower same thing with cholesterol. I know for sure the treating it will lower your risk of having a heart attack for example, or having cardiovascular outcomes. So I do think that measuring your Fitness gives you a leverage to say
Okay, let's improve that Fitness and there are many reasons to do it Beyond mortality. You know, i-i've you lifespan as only one objective of healthcare Health span is at least if not more important. Certainly that's true for
me. Right? I also think that you said you mentioned the the
Changes in VO2 max and so like if you're not, you know improving, you know at a certain point like you mentioned earlier about like people that are doing the same thing, for example, they're not really improving their cardiorespiratory Fitness and I'm wondering if that also goes back to this non-response like what what is this non-response where people will they'll meet the requirements for you know, physical activity guidelines are doing two and a half hours of exercise a week and yet they can't improve their cardio.
Three Fitness.
So I think there are a couple of things to think about their number one is if those people were doing nothing they would be a lot less fit. Okay, that's for sure and I can make almost anybody fitter and I there's a little bit of disingenuous - about the non-responders also its non responders to the dose that they've been given the same thing like saying you telling me you look you know when I take one
Tylenol it doesn't get rid of my headache. But if I take two it gets rid of my headache my husband he just fine with just one Tylenol, right? So I think there is a dose response of exercise just like there is for any other medication that's one of the rationales behind Bob Salas is exercise is medicine. And so Carson Monday and his group in Copenhagen has shown very clearly that if you take someone who's a non-response
Under non-responder in quotes and increase their training dose, they all improve so I don't think I'm sure there must be some people who are non-responsive but in our study in Aaron Hayden's study are in now is a player and cardiovascular expert at the baker Heart Institute in Melbourne, Australia in her study about the two-year training in the 50 year olds. We had zero non-responders
zero.
Row, right, but you were also adding in I think some of those non-response like you said the dose changes or the intensity. They got in some high intensity all of a sudden they're responding. So exact again going back to your point where you know mixing it up and you know, you do want to continue to challenge yourself, right? I mean, you don't want to just do the same thing every single day,
right? And I think that there's a number of benefits to that we're talking now as as a you know, how do you adjust your hygiene? Right? I'm not necessarily saying that you want to do things to steadily improve your Fitness.
This progressively over a lifetime. I think that's almost impossible to do you want to achieve a level of fitness and sustain that over Life as a difference and we coming back then to the performance versus the health benefits of exercise. So I think doing the same thing over and over again as for some people they love it. They find that very satisfying and doing that and preserving their Fitness. I think is important for some people it gets boring and they
On to mix it up, you know and they want to change what they're doing and that gives them more joy and it also helps them stay compliant with this guy activity over a lifespan. So I think though and my own bias is that the different kinds of exercise have different roles in improving and preserving Fitness over a lifetime. I mean, if you want to run your 5K faster, you got to train harder, you know what I mean? But if your goal is look I'm happy with
my you know, 30 minute 5K and I don't care about running that faster. I just want to stay well then then increasing the dose has less benefit for you.
So you were mentioning the stroke volume being really important for cardiorespiratory Fitness. I mean is that the limiting factor like is that how what is the limiting factor for improving your VO2 max? Right.
So I think that for for a lead competitive athlete the stroke volume and the cardiac output are the limiting factor and I know this because I mean if I blood though them and I give them more blood their muscles can accept that.
Just fine and they get faster. Right? So it's just the ability to get that blood to the muscle that's important. The muscle has a lot of reserve and you know, obviously there comes a point where you can't make the hard any bigger, but I do think that that is the primary difference between the elite of the a lead and the sub a lead now that's different. If you told me I've got a 50 year old guy who wants to start raining or a patient, you know with hypertrophic cardiomyopathy.
Apathy a genetic disease of the heart muscle James McNamara at our institution has been studying how you make those people fitter. They've been told their whole lives. Don't train they because you know earlier data suggested that patients with that kind of genetic disease were at risk for dying during exercise turns out that now the evidence in the last couple of years. It's become much more obvious that you can those types of individuals can safely train and in fact,
Allure physical activity and fitness is critical to their survival some animal data suggesting that if they trained when they're young and may even prevent the full expression of the disease. We're working on that right now, but those kind of individuals particularly some who may be limited by cardiac limitations will improve their ability of the muscle to extract oxygen and I think when you get to the elite level everything ends up being optimized maximal lung
Maximal cardiac function maximal muscle function and they are all linked together, you know in the entire oxygen Cascade for people who are sub a lead who have not raised each particular part of that physiological process to their limits can improve vo2max by increasing oxygen extraction. They can increase the enzymes producing oxygen in the muscle. They can increase the number and size of my time.
Kandra, they can and they will increase their AV O2 difference.
They can't increase it forever. And so you increase that and particularly if you've got a cardiac limitation if you're sedentary and don't have one you may increase both in parallel, but it's the cardiac limitation that gets differentiates the highest levels of aerobic Power Fitness from the less lower and let me give you an example, you know, we
we tried we took a group of young people because I wondered how much of
This extraordinary aerobic power is genetic and how much is trainable. So we took a group of sedentary young people the 30s and I trained them to be marathon runners. I trained them to be successfully complete either a marathon or a hundred mile bike ride,
and we made them a lot fitter
some of the largest gains in heart size and fitness than anyone's ever seen including long duration.
To our up to to our runs on on the weekend multiple workouts high-intensity sessions over the week. I threw everything I could have them and frankly I could make their hearts as big as our competitive athletes. You know, I just your lighting the lifelong competitive athlete so I don't know these are young people. These are 30, so well lifelong up until then right so high level competitive athletes. I just couldn't get the heart size the same. They got a lot bigger, but not the
Same I've wondered why that is.
One thing to remember is that the heart is constrained by a stiff fibrous Sac called the pericardium and the pericardium is really important it it allows the right and the left ventricles to function together. Remember the right ventricle pumps blood to the lungs. So left ventricle pumps it to the body and they work in concert so that pericardium preserves that ventricular interaction in a positive way.
Way and it may be that training for one year or maybe even two years isn't enough to stretch that pericardium The myocardium skeletal muscle is very adaptive the pericardium less. So it's also possible that you have to train when you're growing to get the biggest bang for your buck that you know, obviously the pericardium constrains the heart of a baby as much as it does the heart of a
Lead athlete and as the heart grows and adds myofibers this the muscle fibers within the heart the pericardium adapts and remodels to accommodate that it may be that those things have to rise together in order to get the truly biggest hearts of the most elite athletes. I don't know that there are some studies ongoing, you know in Europe and in the u.s. To try to address that you do Klassen and Andre Lagares have the pro at heart study that
Are looking at Young athletes. I don't know that anyone's looking at kids that are starting when they're 12, though. Justin Lolly and instruct is trying to do that group in Norway is trying to do that. So I think that we are as a community trying to get that it's hard to study kids, you know, but but I guess I suspect that you've got a train when you're growing to get the maximal ability, you know it Antonio policia from
The Italian Olympic Committee of the really the one could argue the father of the whole concept of sports Cardiology in the world has studied athletes who have participated in multiple Olympics of the four even five Olympics. That's a lot of Olympics, you know, and what he says shows is that if he looks at their heart size over 12 or 16 years of sustained high intensity Olympic competition, it doesn't get a lot bigger.
You know and so these are people who have acquired that Fitness to get to the Olympic level and then to sustain that over time. It's not that they're progressively getting bigger. They're sustaining and preserving their Fitness and their heart size. But there there there may well be a limit to what that how big that can be. Of course. I mean limited by the size of your body right heart can't just go up continue to get big forever. So obviously there's an upper
Limit to that at some point. Can you sort of
differentiate between so I've heard you talk about I mean this these ad at you're talking about the adaptations to endurance. Yes of aerobic exercise. Yes versus I mean Olympic athletes that are more strength training, right? So in terms of this adaptation of the of the hard getting bigger what a talent, how are the adaptations different
well, so I'm going to give you the traditional thought and then I'm going to tell you that that's not probably
Under percent, right? So the traditional thought what has been called the Morgan Roth hypothesis, is that strength training which does not increase venous return that is the blood returning to the heart. It doesn't increase stroke volume very much because it imparts a huge afterload a rise in pressure during a static strength contraction.
Any idea how much the blood pressure goes up during exercise. Do you know this what which kind of exercise strength exercise if I if I were to have you play
hypertension, I mean 186
times. So if you're going to do if I take a competitive athlete and I do a 90% one repetition Max Squad. What do you think the systolic blood pressure gets too. Let's
go like a multi joint squat like 200
higher coupon 250 to 300. Keep going 400 400 millimeters of mercury.
Yeah, John Sutton and his colleagues put arterial lines and showed that many years ago. So you generate that kind of pressure by intense muscle contraction which contracts the blood vessels. So now you're driving stroke volume into a very small much smaller space than you did before there's massive sympathetic activation from something called the exercise presser reflex, which is real effect is a function of both the relative intensity and
Total maximal muscle contraction and and so that raises arterial pressure very high during the contraction, right? And so to adapt to that in order to reduce the load on the heart the heart has to thicken because the wall stress a stress on the heart muscle is increased by the bigger the heart is but is decreased the thicker the heart is so traditionally purely strength.
Trained athletes tend to have thicker hearts and what we call concentric hypertrophy as opposed to dilated Hearts, which we call eccentric hypertrophy and athletes. You do almost exclusively endurance training Runners swimmers cross-country skiers in the days before skating technique. They have massive increases in blood flow. So
So the adaptation of the heart is to get bigger to accommodate and then sustain those big stroke volumes.
So that's the sort of traditional view the endurance athlete has a bigger heart which is eccentrically remodeled. I mean if I just stretched it without making the heart thicker the walls would get smaller. That's not what happens. Right? The heart adapts gets bigger and more muscular, but the walls don't get thicker a strength trained athlete the heart doesn't dilate the walls just get bigger
and it's The Eccentric hypertrophy that's important for stroke volume and thus
Cardiorespiratory Fitness
exactly, that's correct. Now it turns out that it's not probably not so simple and it's not so simple for a number of reasons because even during Dynamic exercise when you contract your muscles and run your actually occluding blood flow during those two and many sports like rowing for example are an intense combination of both static.
And dynamic or strength and endurance type activity. So rowers every time they pull on the oars. They use a massive amount of skeletal muscle that's Contracting, but they're also doing that in a rhythmic basis, like like a runner or a swimmer. So they're doing both strength and endurance and they have the biggest hearts of any athletes the biggest hearts that you ever see are in the rowers and now in some skates.
Skiers so it'll be skating technique in skiing is a huge strength as well as endurance component, you know and in the for I guess gosh since 1984, if for a 40 years, we've been classifying Sports into their static versus Dynamic exercise, and we created a little Matrix, you know low medium and high endurance.
Low, medium and high static so annoying box factor and and in the Bethesda guidelines for managing of athletes with heart disease, we put Sports in these different bins. We're revising those guidelines right those scientific statements right now, and we're going to change how we display that we've eliminated the individual boxes and we say there are increasing amounts of endurance requirements and a sport and increasing amount of strength.
Events in the sport, but it's not so simple. I can't just put them into little bins because I mean even golfers strength train, right and even some strength trained athletes will do aerobic exercise. So, you know, most football American football players don't do anything more than 10 seconds never, you know, I tend to recommend to the trainer's that even the strength drained those athletes.
We'll be better off if we incorporate some higher intensity. They're the perfect people to do. Not just the Ten Second effort. Wich is all they ever do but do a one-minute or a two minute. I mean, I wanted to multiple multiple play series take last in a for a football game. For example American football game and I think they need to do four by fours or two by twos and that's what's going to allow them to sustain their Fitness.
And not get tired when you know, they're they're playing fast and the sport. So I think we we realize that sport is not so simple. I mean even within a sport, you know, the goalies are different than the than the the full-backs the, you know in American football the defensive backs are different than the lineman, you know, it's it's just really different and so we can't just just
In sports and all the sport people will train with strengthener even Runners are training with weight training and doing strength training even Runners are doing strength training these days,
you know to not try not to bend them, but I'm going to bend them. So let's say purely strength trainers. There is there does seem to be an argument then that they should definitely incorporate some endurance training. If not for the stroke volume increase and eccentric hypertrophy.
Be in the effects on cardiorespiratory Fitness
peso. So I think that for I think from strength trained athletes, it's a mistake not to do any endurance we can argue about what endurance means whether the two minutes or four minutes or 40 minutes is endurance. And I think that there are different ways to skin the cat so to speak certainly for long-term Health that becomes critically important and Jonathan Kim and
It is work very closely with the National Football League to help retired NFL players, you know figure out how to change their training in there eating in their habits to to preserve their health over their lifetimes with a football career is just aren't that long. Yeah. So I think you're right that for performance maybe not for Olympic weightlifting, you know, but for other strength Sports, I think there's no question that
Endurance is important and for sports that require repetitive bursts of strength activities. I think some type of endurance training of some degree, whether that be high intensity four by fours or something is critical for performance and will enhance performance when we talk about cardiovascular health, that's a little bit of a different story and I think that there it is important for overall cardiovascular health in fact
Essential to include that over time and and again, I'll come back to the point that no good athlete does just one thing. You know, I think that's where our studies kind of are are a little bit too isolated because in order to do the research, you've got to focus on and ask one simple question. But training is not that simple and real life
right there. There are people that are
Are much more focused on resistance training and strength training that are not athletes. They're just, you know interested in health and you know, some people wonder well, I'm getting my heart rate up, you know to sub almost maximum heart rate when I'm doing my compound lifts my my deadlifts or my squats and you know how much of that counts towards, you know, am I getting this, you know Improvement in his eccentric hypertrophy and stroke volume or you know, do I need to then, you know,
Incorporate some other types of training as well. Right? So I think you're articulating the CrossFit concept basically, right? And so I think that I'll I'll I'll tell you that it kind of depends so I think that if you ask what happens to the
Heart rate in cardiac output during a purely strength activity. There are things that drive the heart rate that are controlled differently in a strength activity and an endurance activity. Let me let me dig into that if that's okay. This is a little bit of science, please please do. All right. So let's first talk about something called the exercise presser reflex. So simply it easiest to study by doing just a hand grenade.
Rip exercise. Okay, but it would be true for any if I squeeze my hand. Okay, that's the same as you know doing a short static exercise do a hand grip and I do it at let's say 30% of a maximal contraction and I hold it. Okay, heart rate will steadily rise blood pressure will steadily rise if I put a little needle and an efferent sympathetic nerve as it passes by the fibular head that's
My Kroner ography I can actually record signals from the brain to the blood vessels which cause vasoconstriction throughout the body. Okay. It's a brain driven process which comes from feedback from skeletal muscle. How do I know that? Let's say I do that and until I can't do it anymore and I take a blood pressure cuff and I blow it up on the arm and I trap all the muscle all the metabolites, you know, the
the things that are happening in the muscle that are causing fatigue that are utilizing that energy and I tracked them there and then I stopped exercise I Let Go
Heart rate comes all the way back to Baseline immediately, but blood pressure stays up and the sympathetic nervous system stays up and that is the essence of the exercise pressure reflects. The heart rate is now you can ask me is the heart rate controlled by the brain then because I've stopped exercising, right? So the brain is no longer trying to make something happen that's called Central Command or is it happening because the muscle tension nothing to do.
Metabolites because I stopped exercising all to address that my one of my mentors Jerry Mitchell went to Copenhagen and put some little sucker injected some cure re into the nerves which paralyzes them and they have them look at a screen.
And they said I want you to try to squeeze as hard as you did before but because the hand was paralyzed they couldn't contract the muscle, but they could try really hard and heart rate went up even higher.
Even though the muscle was not Contracting so we know that this vagal withdrawal and sympathetic activation comes to a some the heart rate in particular comes from the Central Command. The sympathetic activity also is stimulated by by what's called group 3 and group for large and smaller unmyelinated fibers fibers that are not insulated that carry signals.
From the muscle to the brain and say something's wrong. Let's learn let's get that blood pressure up increased nerve activity constricting the blood vessels. So that's called the exercise, press reflex. The harder you squeeze the longer you do it for okay, the more amount of muscle mass the bigger the blood pressure response. So that's one component. Okay. How is the heart rate regulated during dynamic?
size during running for example
Well turns out that it is almost certainly coming from an energetic signal in your skeletal muscle, how do I know that well some patients have diseases of the mitochondria they're called metabolic or mitochondrial myopathy these and one of my colleagues at The Institute for exercise and environmental medicine Ron Haller studied the he was a neurologist that study those patients he since retired he's not dead
Retired and what he found is when those patients started to exercise their cardiac output went through the roof. They're venous blood looked red because they couldn't extract the oxygen. They had a problem in the muscle, but they would if you and I might increase the cardiac output by about 5 liters for every liter of oxygen uptake. These people were increasing it by 10 or 20 liters as it. So even just walking
down the hall is maximal exercise to them and what that tells us. It is a signal that we need energy. We need oxygen delivered and fuel that drives the heart rate response on the cardiac output response during endurance exercise. So those are two fundamentally different things one increases the heart rate during a muscle contraction from Central Command. The other drives muscle contraction cardiac.
To match venous return the more the compliant the heart the more blood could come back the more it can pump out and those two things are happening to a greater or lesser degree with any combination of movements. That's why I mean it's no longer so simple to talk about just strength or just endurance and then that gets me back to the question we started with why are you training? What's the purpose some people tell me they want to look good. They want their
Muscles to be big they want to have you know, relatively little muscle fat they want to be strong. I said, well then you kind of do a lot of strength exercise, you know, if what you want is to perform during a CrossFit competition kind of do CrossFit work. I think CrossFit is very interesting to me because it's a combination of repetitive strength tyke Maneuvers, but they also
Repetitive muscle contraction. So I think that kind of exercise does have both an endurance and a strength component Mike Emery from Cleveland clinic now is a huge fan of the CrossFit type training and believes that it will get you a combination of eccentric and concentric type hypertrophy. And again, it's where you know this Morgan Roth hypothesis.
Is kind of falls apart because it's not one thing or the other. It's kind of a combination of both. I don't think you can lift free weights and expect you know that yeah, I slammed down the weights on the floor walk around in between my sets that you're going to get an endurance type trained heart that requires a more sustained repetitive contraction and more Dynamic type exercise to include
Age I know that's how is little complicated now that
help wonderful. Wonderful. I mean I also love that you did bring up the CrossFit, you know that they have been doing CrossFit for the last few months. And and also there is a Corp incorporation of a lot of high-intensity. There's rowing there's jumping rope. There's getting on the bike. So it is, you know, like you said it's not, you know, you can't just put strength training and resistance training in one bin and endurance and another particular with a lot of these programs now that are available like CrossFit orange theories another
On they do you know, they have something very similar but you're right just like if you're just raising the dumbbells and doing you know, you know, there's not as much of a the endurance kind of training there. So it's good to talk about the science there on that. I kind of want to go back to the blood pressure thing as well because there was an interesting study that was recently published that made a lot of headlines on these isometric types of exercises write the static hold and
Being better at improving blood pressure. What is the best exercise to improve improve blood pressure? Right. I mean
that's so you know in when we take care of patients with hypertension. The first thing the the community tells us to do is lifestyle modification reduce intake of salt reduce intake of alcohol. Make sure you're getting plenty of sleep and increase exercise and and I will say that traditionally my Approach has been that
Hammock exercise is best because that causes relaxation of blood vessels. That's how you get the blood to the exercising muscle and we'll do one more little science thing. Okay, because the body has both a general alerting response as a function of the exercise presser reflex and a local response. So when I'm exercising hard,
the muscles that are Contracting are relaxed
Blood vessels everywhere else or contracted. It's really interesting. So if I'm running the blood vessels in my arms are Contracting as they are in my kidney and my gut that's why you sometimes will get catastrophic gut, ischemia during extraordinary endurance exercise because you just don't have enough blood in your circulation to maintain your blood pressure. If you've got a lot of skeletal muscle that's requiring blood one thing.
That the will call this call at the saltine hypothesis about the cardiovascular limitation to exercise because if you add arm exercise why you're doing intense Lex exercise you start to constrict the blood vessels even in the legs because you simply cannot sustain your blood pressure with all the blood vessels relaxed even with a maximal cardiac output.
So the blood the blood vessels have to constrict but they constrict from this General alerting increased sympathetic activity. But in the muscles, you get something called functional sympathize lysis what that means is the muscles are releasing metabolites as not just from the muscle, but from the blood vessels and from the red blood cells themselves ATP and ADP are dramatically
Didn't they so dilators? So you get constriction in one place and dilation in another place and it is the regular contraction the need the release of those metabolized the driving of the cardiac output response that causes relaxation of the blood vessels and that's what I want and hypertension. I want the blood vessels to be relaxed. Remember we started this by saying blood pressure. I did maybe I didn't we talk about the thick equation blood pressure is also a function.
one of two things
two things only cardiac output and Vascular resistance, right? We talked that cardiac output is heart rate in stroke volume. So blood pressure is the triple product of heart rate stroke volume and Vascular resistance with probably resistance being am a very major component. So so what I typically think is that people need to do sustained and Durance activity to dilate those blood vessels cause that relaxation and let those blood vessels start to
Lacks as a best way to reduce blood pressure. I don't know what to make about the static training study. It's just one study. It's really contradicts a lot of other data in the literature. I don't think that people say, oh, let me quickly switch to doing plank seeing leg sits against the wall just because this one study showed a low blood pressure, you know for the most part.
Janet Leigh, if you have hypertension, and I've already done your lifestyle modification it probably going to need medication to drop your blood pressure hypertension is a cardio vascular disorder and we've learned that you know, a lot of people are going to develop it. And so I think the lifestyle stuff is the foundation. I don't think it's going to make a huge difference whether you
You whether changes my prescription for Life That Remains the Same and I think having a strong component of endurance exercise but incorporating strength because that's important for life and sand and function as you get older. I think all of that is really important and it's not going to change my prescription, you know, I do have specific approaches to hypertension and Physically Active people, but
I will remind your audience that many people are salt sensitive and reducing salt intake in the diet is important if you have hypertension and maintaining a high potassium intake is also important and then watch your alcohol because I think sometimes doctors don't tell you that but that too much alcohol intake is a very strong contributor to hypertension and making sure you've got good.
Ben don't have sleep. Apnea. So sleep apnea is another thing if you're a spouse or partner snores that maybe one and as hypertension talk to a sleep doctor that may be something that's a little easier to manage and will can cause dramatic reductions in blood pressure.
So along with those you think it's possible to with lifestyle intervention reverse
hypertension, I think in some cases
In mild hypertension. I think that that's true. If you got hypertension in a young person under the age of 40, I think you need to look for other causes. I don't think we look hard enough often enough. Probably the single most important is to measure a renin and then I'll down strewn to look for hyperaldosteronism production of one of the hormones that raises the blood pressure by the adrenal gland and the kidneys.
That ends up being really easy much easier and more directed to treat and it's grossly under diagnosed in our country. So you should have a wiener and n and L dosterone level measured. There are other rare causes of hypertension severe hypertension and young people should get a plasma meta nephrons to look for unusual tumors or the adrenal gland, but I think that garden-variety essential hi,
Hypertension at least at its earlier stages can well be modified by behavioral modification that we've been
great. Including someone who may be in their late 60s if they perhaps do the training the Sleep looking to sleep. Yeah alcohol intake. Yes, all of the
things that can have a huge effect. Okay. What about I've heard you
talk about recovery and Recovery days being as as important as
How much load you're putting on your heart and see how much training essentially? I'm curious what you mean by
that, right? So so recovery is a essential part of training and I think most athletes and coaches understand that but but it's a way that many athletes get into trouble because if they're not performing as well as they want. They think oh I just need to train harder.
And that ends up just getting them into a vicious cycle of increasing over training, you know, the athletic Community has thought a lot about this overtraining syndrome for years as a guy from the Netherlands in arm Kuiper's who did a really interesting study with horses, you know, we're starting with a great endurance athletes of our time of our world right biologic world and he tried to over train them. And first thing he did was he increased their base tray.
Load and they all got faster and then he said, okay. Well, let me increase the intensity of their training and they all got faster and they said let me increase the number of intensity training sessions and they all got faster and finally said well, I don't know what else to do. Maybe I'll just change their recovery and what I mean by recovery is, you know, they do a high-intensity session in the morning and then the next
First session after a high-intensity session is something easy. So it's simply a simple Cantor just a walk around to get the blood moving. And as soon as that within the week of increasing the intensity of the recovery sessions, they were all over trained with marked reduction in performance increasing resting heart rate fatigue, you know every sign of overtraining so so in order to reap the benefits of a train
In stimulus the body has to do something right the muscles have to produce protein the blood vessels. There is a release of a variety of Downstream metabolites of from the oxygen sensing Cascade from hypoxia-inducible Factor through vegf the vascular endothelial growth factor thing that make the blood vessels that improve the
the lining the endothelium that that add muscle fibers that make them bigger all these things have to happen. That's what beneath you know, the skin. Those are the things that are happening after you do a training stimulus, right? And if you don't allow those their full expression, then you won't get the benefit of the workout that you do and so most
Good coaches and trainers will always incorporate an easy session after a high-intensity session and always I think should always have a day off whether that day off is some you know strength training or Technical Training or things like that. That's okay by me watching film doing some basic technical things shooting free throws, if you're a basketball player whatever but it has to be something easy. That's unstressed.
And that's what allows you to to get the most benefit and I think that people who are not coached, you know, or who have a coach that's perhaps a bit more inexperienced they get they get driven to do more and more and more and they find that they're not getting better. And that's probably because you're not having adequate recovery and one of the things we did in all our altitude training studies. We spent more than a decade studying. The best way to do altitude training for are USA Track and Field in the
U.s. Olympic Committee is to monitor early morning heart rate. That was our best indicator. So we'd have the athletes put their heart rate monitor on, you know, set an alarm put their heart rate monitor on if you've got a watch it rest. It's pretty accurate during exercise the watches that just use the PPG the platysma G are not accurate. That's a whole other discussion that we should talk about, but put it on at rest and and track it for go back to sleep.
And see what it was for those five minutes before you woke up again. And as you start to get overtrained that resting heart rate starts to climb and that's a signal that okay. I need to reduce the frequency of my intensity sessions need to make them a little shorter or I need to make sure that I'm heading out of with recovery and take a day off
and adequate recovery. If I'm just I want to make sure I understand this it includes on a day your training doing something a little more light
strands of a rubber.
Your size it might if you're used to doing stuff in Zone 3 and zone for or zone 5 you might do in a Zone 1. Okay. So did you know what I mean by those five zones I go ahead and I would be great because it seems like definitions vary depending on what Journal you're reading. And I think that that's true and there are different coaches who use different zones for us, you know, and I learned, you know, my basic practical exercise science from Jim straight understand my partner in crime over.
Sorry, yeah. Yeah, so from Jim straight Gunderson who passed last year my good friend and partner.
I'll get there. Just give me a second.
Okay, so I learned most of my exercise science from my good friend and partner Jim stray Gundersen who unfortunately passed from pancreatic cancer last year and we and all our studies we use 25 training zone model. And typically what that means is we would pick the generally the second ventilatory threshold where ventilation starts to really increase out of proportion.
To oxygen uptake where vev CO2 has gone down to its nadir where a lactate is between the two to four millimolar range. They all reflect what we call the maximal steady-state. That's the highest level that you can sustain for a prolonged period of time most good marathon runners are running at the maximal steady state and let's just say for argument's sake that was at a heart rate of 150.
Because there's no magic to heart rate and it changes on a day-to-day basis. We're not machines. We would bracket that and call let's say the maximal steady state or threshold or is Zone 3 training would be 150 to 160. Okay, then Zone 2 training is about 20 beats below that so 130 to 150. Okay, and then Zone 1 or recovery is less than 130.
So we're recovery effort would be below. The lower limits of Zone to now zone for is probably the the my still pressing this too hard. I'm sorry. Okay. So zone for is probably the hardest to quantify because in the physiology world you need to bring people back and do multiple repeat testing to do that zone for is what we call critical power. That's the high.
Highest intensity you can sustain without failure without a drift towards vo2max. So when kipchoge I was trying to run the under two minute a two hour marathon, but kipchoge was trying to run the under two hour marathon. He worked with Andy Jones and Mike Joiner and trying to say what exactly is my critical power and it's amazing. If you look at Andy Jones from the UK's work, I mean, he does exercise.
NMR magnet and looks at truly, you know phosphocreatine ratios and hydrogen ions one or two. W differences is a difference between sustainability and failure. It's extraordinary and it's delicate and it's hard to pick and it's my belief I think and he's also is that the reason that some of these great Runners from East Africa or some of the Great?
Swimmers spend so much time doing what they're doing is they want to feel what they got to figure out what the Pacers own for is. They have to know what that is and it's hard to prove that in a lab everybody the good athletes know that when can you push that pace and one day after back off? And so we know zone 5 because we're measuring maximum heart rate. And in the model that I gave you let's say the max heart rate was 180. Okay. So the top of the Zone 3
Is 160 so I often what I typically will do in the lab is I'll split the difference and we'll call zone for 160 to 170 in zone 5 170 to 180. And so that gives you a nice broad heart rate 5 Zone, which reflects different kinds of events. So Zone 3 typically is a marathon and all calculate running economy.
And so I know the speed at any given oxygen uptake for a runner for example, and also if I take Zone 3 heart rate and and running economy, I can tell you what your marathon time is going to be and if I figure out what zone for is that's about a 10K Pace or so, so you can't run that pace at an entire Marathon, right, but you can run it for you know, 45 minutes or an hour right and then five.
5K and shorter 5K is run at VO2 max. So 5K is run at so in zone 5 and anything shorter than that, right? We know for sure that you can't run 10 meters a second for a marathon. You can't even run it for 5,000 meters, right, but that's still going to be zone 5, right. So anything that's you know, pretty much.
You know a 5K and shorter will be run at those higher heart rates in those higher training zones for endurance activity. So you mentioned the importance of looking at your resting heart rate early warning for Recovery is sort of a good as a guy the guy raining right? What about you hear a lot about heart rate variability? Yeah. So, you know, we spent decades
There's probably a hundred papers about cardiovascular variability. So first let's ask what is heart rate variability. So hurry variability looks at the change in heart rate over time and there are two this is grossly simplifying it but there are two main stimuli to heart rate variability. Number one is respiration and breathing when you breathe there are two things that happen.
Your brain is sending signals to your diaphragm to breathe the nerve that carries those signals also goes to the heart. That's the vagus nerve. There are also changes in blood pressure and stroke volume that occur as you breathe because when you breathe in your decreasing intrathoracic pressure blood flows into the heart when you breathe out the blood comes out of the heart, so you're changing stroke volume, you're stimulating the arterial baroreceptors which are in the
Added arteries and in the arch of your aorta. So so there are a number of things that happen when you breathe that move blood in and out of the heart and also send neural activity from the brain to the pacemaker of the heart. That's the respiratory variability that happens at the respiratory rate, you know, then there are other intrinsic rhythms within the circulation they happen a little bit slower.
If you think in terms of cycles per second or Hertz, you know Point 1 Hertz or 10 Cycles a second is the low frequency Meyer wave frequency. And if I were to measure sympathetic nerves, the mire frequency is mostly sympathetically driven not entirely it's sympathetic and vaguely driven. So the problem is is that
at all measures of heart rate variability when you use a heart rate monitor do not take those into account. So if I told you to breathe at six breaths a minute, I would slam the high-frequency on top of the low-frequency Rhythm and I would markedly increase your heart rate variability. If I had you breathe a little bit faster, I would separate those out and most of the heart rate variability that's being measured by your heart rate devices.
Bam,
most of the heart rate variability that's being measured by your heart devices is mostly looking at the high frequency variability, but that is absolutely dependent on respiratory rate and nobody controls that right. You're not giving them a tone that tells you you breathe at this frequency and and we'll measure your higher availability. No, it's not doing that and then I'm going to add one more that as you move around.
Around very low frequency rhythms will alter heart rate. So when you stand up heart rate goes up when you lie down our it goes down. When you pee your you have with vagal withdrawals the only way to pee so your heart rate goes up when you pee, you know, when you talk to somebody or are we goes up? These are uncontrolled factors in my laboratory if I control every single Factor so same time of day same food in the body say
same I control how deep and how fast you breathe. I can't get better than plus or minus 25% day-to-day variability.
So I'm just telling you that even under the best of circumstances these measurements are very technique dependent and very variable. So I don't think people should use them as an indicator of anything because I think it's to the science is not there the you can read a lot of articles about heart rate variability. I was the thesis advisor and and opponent for
one of my good friend heikki Ruth goes from Finland from avascular students who tried a lot to look at heart rate variability as an indicator of training and overtraining and it's just too hard to standardize and get right. So I think you if you tried to use that except under extraordinarily controlled conditions, I think in find. Yeah, I think that you'll find you'll make more mistakes than
well. That's that goes with with my gut was telling
Maybe because I can with my training I can see improvements in resting heart rate. I can see it in my heart break my maximum heart rate going even lower like getting lower but my heart rate variability according to my Apple watch nothing. So we you talked a little bit about you know, this the performance cardiorespiratory performance and limitations and and that got me to thinking of, you know, men versus women and the sex differences and what so my husband and I go
go for a run together and he smokes me every time like he's faster. Yeah, and you know that we're not doing a 6 hour run maybe that would change maybe I would outperform him. Who knows but I'm curious like what are the cardiovascular performance differences between men and
women so so you're asking a really interesting question and there are some fundamental differences between men and women particularly, you know, younger men and women which is virtually all due.
The androgenic effects of testosterone testosterone builds muscle reduces fat builds blood volume makes the heart bigger makes the body bigger changes the power outputs of skeletal muscle. So so that's why we have women's sports right is because men and women given equivalent access to training and coaching men are still faster. And if you're interested in reading more about this we
Just published a definitive scientific statement about the biologic differences of sex from the American College of sports medicine Sandra hunter from Marquette is the first author on it. It's been published in the public domain. It just came out a number of months ago. So that that has a lot of information about this, you know, if you looked at I'm not sure I'm going to get the exact numbers, correct, but if you looked at in the some of the great this
Middle distance Runners female middle distance Runners house and Felix Sandra richards-ross, you know, those are the great names that we hear about in know about it and women's women's middle-distance sports. And if you looked at their world records that they set during the peak of their career at the same time twenty thousand or ten thousand boys ran faster.
Boys night these are high school kids if they had to compete against the boys, we would not know their names. This is not this is not benign. And you know, if our society wants and Views having women sports and women to be able to be successful which I think is a tremendously important goal. It's important that women compete against women and men compete against men and let me say that differently. It's important that males compete against males and
females compete against males because there's a difference between sex and gender. I don't want to get into that. I don't think that's what we're here for but biological sex makes a difference particularly the sex that you are your biological sex as you go through puberty, that's where the differences between boys and girls start to become most dramatic before puberty. There's not much of a difference, but it's at puberty when the massive increases in testosterone come about
It and and you know, your husband's going to beat you now, I wouldn't beat you, you know, because I'm an older man and I'm not a probably not as fit as you so it's not that every man is going to be every woman. That's moronic. Right but given the same training and the same level the males are going to run
faster. Now the same age what about this? There was a study this year that was published.
In the Journal of American College of Cardiology claiming that women can reap the benefits of aerobic exercise with doing less exercise as men. So it was like twice as less exercise and they had yeah same
cardiovascular. So I'm underwhelmed. You know, I think that there's not a huge amount of benefit. The bottom line is that premenopausal women that they just don't have a lot of cardiovascular disease. There's
Nari protection against cardiovascular disease by estrogen and progesterone and you know what? I tell many of my patients is is one thing that will turn a woman into a man and that cigarette smoking, you know, so cigarette smoking abolishes most of that difference and we see that clinically all the time, but I think that that women should not necessarily consider that their dose response relationship to
Sighs is fundamentally different and that's why you know after menopause, you know, all those differences basically change. And so what happens is you simply shift now, once you've got a woman who's well past menopause now from an endocrine logic perspective. She's much more similar to a man and now the risks start to accelerate at the same level at the same rate that just pushed off by a decade.
What if she undergoes hormone replacement
therapy? Yeah. Yeah.
It's that's an interesting question and there are risks and benefits of that right? I think that the there are clearly benefits cardiovascular benefits particularly if the hormone replacement therapy is started early in the menopausal transition when it starts later, you lose the protective effect and you increase the risk of breast cancer and other bad things that counteract male female
mortality differ. So the timing of
Of a timing I think is there's obviously been studied by dozens of people and hundreds of thousands of women. So that's a whole another complex task, but I think the simple answer is I wouldn't count on it. I would say that the dose response relationships are the same and we've seen that we have always tried to incorporate women in our studies. We the only studies that included women in all our altitude training studies because women are competitive athletes and we need to know how they
On to altitude we did the same thing in our year-long training program. So to our community everybody knows this but we have to include women in all our studies. It is essential but I don't think women should think they are special in terms of their adaptation to exercise. We mostly found in the same except except that in our year-long training study women increase the size of their heart in the first three months.
Similar to men and then they stop they plateaued and the men continue to increase and I think that's a testosterone phenomenon. It's another example of why testosterone enhances the building of cardiac as well as skeletal muscle. So that's one of the fundamental differences.
Well, I really want to get into some of these risks with now comes with extreme exercises are really also an expert in that area and there's been a lot of interest and worry in
You know in extreme exercise like I guess we should Define what that is, but in some instances you can find study saying seven and a half hours of exercise a week can in some cases what they call Double the risk of cardiovascular disease in I think you'll clarify maybe the depends on they're actually looking at other biomarkers not necessarily someone dying of cardiovascular disease, but what what is Extreme exercise? How does it affect coronary plaque?
Calcium what is coronary plaque calcium? Why is that significant? Okay. All right. So so first I think extraordinary exercise in couldn't be defined by multiple different things from a epidemiological cardiovascular health perspective. I think what we're talking is about people who do more than three to ten thousand minutes a week and I'll tell you why I chose that in
Studies in the Cooper Clinic, we used more than 3,000 minutes a week, which is about a tower and on about six hours. But on average are high volume exercises did about 8 hours a week. So the nadir where you reach the maximal cardiovascular benefit is about five hours a week five, maybe up to 10 hours a week for heart failure outcomes once you get more than about 10 hours.
Hours a week you're starting to get to well, I think most would agree on Extreme exercise the coronary calcium story is interesting, right the original concern about coronary calcium came from the German study by mollenkamp. What they looked at a group of Runners who had done lots of lots of marathoners and found that they had more initially when they compared them to a population-based study the Heinz next door fecal study. They didn't have more coronary calcium.
But that the authors of that study kind of said well, that's not fitting. Our hypothesis part of it is the athletes had better risk factors than the controls. So they said let's only select athletes wear the same risk factors as a controls and then the athletes had a little bit higher coronary calcium and a little more nonzero calcium's but 50% of those Runners were smokers and they all started training later in life. And that's a that's a consistent.
Theme in much of this world. So a lot of the the Masters athletes tend to start later in life. They're not the young Elite Olympic athletes and many of them are doing it to try to combat bad behavior when they were younger. So so just keep that in mind when we look at then the next big study was the one
out of the UK, which did CT angiography which looked at more than just coronary calcium. And now it's a good point to step into that. Right calcium is the footprint of atherosclerosis. So as the atherosclerosis the hardening of the arteries that we think about is cholesterol mediated as that progresses from accumulation of cholesterol their import into macrophages the cells that suck up the cholesterol into the lining of the blood vessels and injured and start to
to accumulate and obstruct the blood vessels as that heels or progresses. There's always a little bit of there's a plaque little plaque rupture a little bit of injury here and and the blood vessel calcifies.
It's not the calcified blood vessel that I worry about. It's the company it keeps because calcified blood vessels. Don't crack don't rupture and don't cause heart attacks. Okay, it's the non calcified. What's often called Soft that's not really soft. It's just non calcified plaque that ruptures and causes a heart attack occludes the blood vessel. That's what a heart attack is. So the more calcium you have it's really just a sign that there's more non calcified plaque.
That makes sense so that the atherosclerosis dick burden is higher and that what the British study showed was that first of all.
They're female participants and almost no coronary calcium and no atherosclerosis. So let's talk about toss out the women for a moment. But the male's the the higher intensity more volume athletes and more plaques and more calcified calcium. What was interesting though is all the plaques were almost all calcified and in the non-athletes, it was a mix of calcified and on calcified plaque and they're the ones who first
Raise this issue is maybe exercise training stabilizes plaque and makes it more calcified and that's why it's the athletes tend to have a lower mortality in a lower risk of a heart attack. So but none of those studies looked at events, right? They just looked at the anatomy of the arteries. And so that's where our Cooper Clinic study came in lower a defeatist paper in Jama from 2019. We looked at
25,000 people, you know with multiple different ranges of physical activity from the middle Group, which is sort of that guideline directed three to five hours a week a low group who did less than three hours a week and then a high volume exercise. Was it about 8 hours a week? Okay, and it turned out that about 75% of both group all three groups about 75 percent of them had
Lovely little coronary calcium and and the number we worry about a score of 100 because that's where the the higher the calcium level above 100 the greater the risk. So that's sort of our clinical cut point where it becomes really clinically meaningful and among those individuals who have the majority. So 75% of our group had coronary calcium scores less than 100. There was no difference in coronary calcium among the
Three different activity groups and a 50% reduction in events quite dramatic. Now there was a small about 11 percent increase in the risk of having a calcium score over 100. I'm parsing my words carefully. There was a little bit of a greater risk of having a higher score. But if I look in all the individuals who had scores over 100, there was no difference in the absolute score between those who did no activity and those who did
Eight hours a week and there was a 25% reduction in events didn't quite reach the testicle significance, but it wasn't a greater increase for sure. No greater increase. It was a lowering and the bottom line. If you look at now absolute versus relative risk, which were coming back to we talked about at the beginning you're better off having no calcium than having a lot of calcium. Absolutely, right because calcium is a sign of atherosclerosis.
Yes, if you've got calcium you're better off being fit then unfit. Okay, and in Nina radford's paper also from the Koopa Clinic, we showed that there's an interaction between calcium and fitness. So the higher your Fitness the closer the high calcium group comes to those with no calcium. So if you're unfit with a high calcium score, that's a disaster if you're very fit with a hike.
Same score you're worse than if you had no calcium, but not that much worse because the thickness ends up being protective what causes calcification and atherosclerosis. I mean if I knew that I'd have the Nobel Prize, right? We have lots of I mean billions of studies about the nature of atherosclerosis. Ohmic losses it but it's due to many of the risk factors. We know high cholesterol how that cholesterol interacts with the vascular wall hypertension smoking diabetes.
He's and your parents
it genetics if you are so the question is if you're measuring let's say by CT angiogram looking at the quote unquote soft plaque which isn't so soft but it's not chalcedony cast fight back then it does physical activity reduce plaque
formation. So the I have to say that just a few months ago or last year the the pro at heart study that I mentioned you before kind of threw a big
Wrench into this because they looked at Elite low young and older athletes and they did show more plaque related to high intensity endurance activity. I don't know exactly what that's going to mean. I don't think that exercise removes plaque. I don't think you can count on that it may it certainly provides protection.
it makes against cardiovascular bad outcomes and it may cause the non calcified plaque to be more calcified and more rupture resistant, but I don't think it makes it go away, you know, there are idiosyncratic studies, you know, looking at, you know this training and this reduction but there's also a dios a syncretic studies showing you no you no air bag of show didn't run across the America that when they did that
That they had an increase in plaque, you know, I will tell you because I just got it. I got notification yesterday that we have a new paper in from the Cooper Clinic showing that if you look at try to parse out the exercise dose into intensity versus duration as you increase the intensity.
Calcium goes is less. And as you increase duration calcium goes up. So I think the higher intensity efforts are probably more protective and the very longer duration. That ones are probably more calcium inducing why that is I don't know. You can look at some of Wendy courts data from Colorado. She's the one who's shown that that when you start to exercise
sighs calcium in the blood goes down that causes an increase in parathyroid hormone and parathyroid hormone causes leaching of calcium out of the bones and where that calcium is going when it goes out of the bloodstream. I don't know, you know, maybe some of it gets deposited in the blood vessels. We don't know exactly what the path of that calcium is. I think this is an area of active investigation, but it's one of the reasons why endurance athletes, you know, always
I told this is going to protect my bones, but it doesn't doesn't protect your bones and actually may worsen it. Some of that is nutritional. But also it's because of sustained increases and parathyroid hormone and sustained leaching them of calcium from the bones to preserve blood calcium levels, which are essential to everything that is necessary for Life the other
I would say the other outcome. We're not necessarily outcome, but risk factor for a negative outcome that people are worried about the extreme particular extreme endurance activity is atrial fibrillation afib. Yeah, so what's interesting though is that you look at numerous studies. There's a decreased risk in afib with increasing physical activity, but it seems as though there might be a certain point when that changes. It's
absolutely true and it's the one thing I tell all my
His athletes, this is one of the consequences of the duration and the intensity of activity that you do is you'll increase your risk of atrial fibrillation. We know why it's a very elegant study by again ghetto Klassen and André laguerre which talks about the damning effect of the valves. Remember that the heart has a upper chambers called the Atria that collect the blood and pumping chambers called ventricles, which eject the blood out of the heart.
In between them are valves AV atrioventricular valves on the left side. It's the mitral valve and let's talk about that one for a moment because most of the atrial fibrillation is probably generated within the left atrium. So when the heart contracts that mitral valve snaps closed, right and the blood gets ejected out but the blood continues to flow into the atrium because the cardiac output is increased right? So it's got to keep flowing in the blood doesn't
just stop it accumulates in the entry and that's called the reservoir effect of the of the Atria and then when that valve opens the pressure that has built up in the Atria drives a blood into the ventricles to help fill it and then so there's blood to pump in during the next cardiac cycle that make sense. Okay. So now let's take exercise which increases the cardiac output so increases the speed and volume of blood that's being pumped.
Pumped and now the other thing it does is increases the heart rate and when you increase the heart rate now, you have more Sicily's so instead of having the valve open.
now it's
And you spend more time with those valves closed and so it creates a damn in between the Atria and the ventricles and the Atria just dilate and as you dilate the Atria you increase the risk of atrial
fibrillation at what point I like is there like a amount of
exercise? Yeah. So so that's a good question because the Trump so heart study is probably the one also from Norway which shows the point that you made and we all know that
Being unfit is also a risk for atrial fibrillation and probably that targeted middle dose. If you will three to five hours moderate intensity physical activity gets you to the nadir in their population based study as you got past that you started to increase the risk. There was a lot of noise around the point estimate and nowhere near that, you know, increase it by I can't remember exactly. Bye.
One and a half time something like that. Nowhere near the fivefold increase that you see in the competitive athletes. So so I don't think anyone who is doing recreational or even occupational exercise needs to worry about afib, I think, you know particularly as we've talked about the optimal dose for health and joy and wellness, you know is up three hours is what's recommended up.
25 3 to 5 hours probably gets you most of the bang for your buck. And as you start to get beyond that for performance, then you accept to accept the risk of atrial
fibrillation. Now the risk of afib the reason Peds people worry about it is increases stroke do athletes have an increased risk of
stroke athletes in general don't have an increased risk of stroke. Anybody with atrial fibrillation has an increased risk of stroke do athletes have less of an increased risk, Maybe.
But we don't really know that for sure. So so I think that you know, it's easy to protect yourself from Stroke by taking in a coagulation. They are of course we base that there's obviously risk to taking blood thinners because you know, you may bleed and for some athletes like cyclists who get into crashes. That's a bad thing. Right? So depending on the nature of the athletic athletic event. Someone is a runner or swimmer.
I think you have to worry about it. Right but cyclists when you are risk for a crash or you know other kind of athletic events than involve collision and that becomes an increased risk if you're on a blood thinner, so we don't know the best way to manage that some of it depends on how often you're in afib afib is some can be paroxysmal meaning it only occurs intermittently or it can be perceived.
Assistant or permanent but ends up being persistent or frequent then ablation is a way to go just keep it from happening. There's a new study out called react. It's actually recruiting right now and and we're saying we're asking the question if someone develops a fib, can I just
Take an accumulation for a couple of weeks right then and then take a medicine to get rid of it. And then when I'm back in sinus rhythm, stop taking the medication so only take it when you're in afib that requires you to be able to detect it either symptomatically with your watch and we just don't know most right now are saying, you know, if you have other risk factors older age hypertension diabetes heart failure other heart.
Eases but increase your risk of a stroke. It's probably better off taking the anticoagulation depending on what your risk of bleeding is and that depends on your sport and the most endurance athletes have a lower risk factors. Probably. I mean generally speaking most of them. Do you know and if we there's a scoring system that we use called Chad's vasc don't worry about the details of that that help you define that risk. Unfortunately there weren't a lot of elite athletes in
It's the populations that developed that scoring system. So I don't know how perfect it is for a competitive athlete but for a middle-aged athlete under the age of 65 with no other risk factors, no hypertension of diabetes. No other heart diseases the risk of anticoagulation is probably greater than the risk of stroke. You know, you have to say well, you know, look, I'd rather take anticoagulation than have a stroke. You know, I'm willing to accept a little bit of a risk.
Uuuuuugh that's a discussion to have with your
doctor, right? I want to be mindful of your time. I know you have to leave one quick question life expectancy of what we would call this extreme type of endurance training. Yeah, what data is there to support or
refute? Yeah, you know, I think that as you get out to the extremes of age most things start to fall apart, you know, so I think that what enables somebody to sustain extraordinary
Eyes at the edges of lifespan. So after let's say 85, for example, the extreme old is really joints and muscles. It's nothing to do with the cardiovascular system. So you need to be able to run, you know, those durations or without injury requires some unique genetic predisposition. So I don't think that anyone should be an extreme athlete because they hope that it will make them live longer.
And I think that would be presumptuous regardless of whether there's you know, a small study here or small study there. I don't think it increases the risk, you know, there was this the Danish Copenhagen heart study which frankly should never have been published as ridiculous which looked at Runners who did a lot of running this one that generate a lot of press but people who did a lot of running
An increased risk of death. How do they know that there were two deaths? What are they die of I have no idea maybe that guy hit by a car while they were running, you know, and the confidence limits on that point estimate were so big as to be useless. I think that was a terrible study. And in fact, we have we presented at the American Heart Association a few years ago. We looked at the coup again the Cooper Clinic database we looked at more than 10,000 meant minutes a week. This was stimulated by a burfoot by the way, who asked us this question.
What about you know, you say only 8 hours a week. That's nothing from any of my Runners. I said, okay. These are bad guys average 30 hours a week and there was no increase in mortality. There was no increase in events the number of car. It wasn't a lot of people twice the number and the Copenhagen heart study, by the way, you know, how many cardiovascular death zero so so I I would not I would not say I'm worried that my extreme athletes are going to take my life.
I don't think that that there's the evidence is strong in that regard. I don't think there's evidence that it will prolong your life and you have to as you start to get to older and older you really it's healthspan lifespan that matters the most.
Thank you so much. Dr. Levine. I mean this has been incredibly informative. I have so many more questions that I would like to ask you. Maybe we can do around to some time and thank you again.
For all your research all your contributions, I mean just moving the field forward in our understanding of how physical activity affects the you know cardiovascular adaptations in the how that does improve our health span and to some degree our lifespan. So
what's absolutely my pleasure. Thank you. And therefore your you know, Wonderful your homework that you do prior to these interviews. It's really quite quite impressive and you know, the your podcast is high quality and reaches a
Lot of people, so thank you for
inviting me. Thank you.
A huge thank you to dr. Benjamin Levine for coming on the podcast to share some of the most valuable information on how exercise prevents and reverses aspects of heart aging and a big thank you for listening only a few quick reminders and mentions first. Make sure to check out the recent guide on all things omega-3 supplementation this valuable distillation of a mega three science will put you on the right path to understanding how to pick a good omega-3 supplement some of the benefits how proper
dosing can significantly enhance your omega-3 index and many common concerns. You can find that Omega 3 guide at no cost at FMF omega-3 guide.com. Once again, that is FMF omega-3 guide.com. The other thing I'd like to mention is that some aspects of fitness and athletic performance are genetic if you have used a consumer genetic tests, you can reveal some interesting information.
About those traits for those of you with raw genetic data from services, like 23andMe or ancestry DNA. You can get a free report on my website. This includes genes that affect endurance levels those that affect VO2 max through training your muscles ability to transport lactate and even your susceptibility to muscle fatigue and injuries in tissues such as the ACL and others to get your free genetic fitness report visit.
Visit found my fitness.com forward slash genetics and scroll down to access our free reports. It's a really great way to use scientific insights to enhance your fitness journey. Once again, that's found my fitness.com forward slash genetics. And lastly if you're not already following along you can find me on social media under the handle found my fitness all one word on Twitter Facebook Instagram and tick-tock.
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