The Role of the Heart in Peak Athletic Performance

They say you lose about one beat per minute per year.

Why does that actually occur? For whatever reason, you can't engage that sympathetic nervous system, fight or flight, as much, which engages that max heart

I remember when I was like 21, 22, I used to have a max heart rate of 206 and now it's probably sitting around

but it's definitely come down, you know, almost 40 beats a minute

years, so yeah.

Hello and welcome to the Athletes Compass podcast where we navigate training, fitness and health for everyday athletes. As we learned in the first of the Athletes Compass series on VO2 max, which we'll link to in the show notes, there are several limiters preventing us from having a high VO2 max. In the last episode, we learned about how the lungs can be one of those factors and what we can do about it. But today we are going to talk about how your heart

and the entire cardiac system can be a limiter to a high VO2 max and your power and pace at VO2 max and what we can do about it. We're going to get into the weeds a little bit with the science, but as always, we'll bring it back to practical applications for everyday athletes. So Paul, let's review quickly what we mean by limiters of VO2 max and ⁓ is this a limiter of VO2 max capacity and or your power and pace at VO2 max.

Yeah, right. So thanks, Paul. Again, just to recap and recall, when we're talking about VO2 max, everyone knows we're talking about the maximal volume of oxygen uptake. So you're taking the air, the oxygen that's in the atmosphere, and we're delivering it through the system to get it into the muscle cells so that we can convert that chemical energy into mechanical energy. All right. So we want to get... And the more you can do that...

the higher your VO2 max value, ⁓ there's a very close link between performance and VO2 max. And it just so happens also health and longevity as well. It's an important factor for your overall function, how well you'll live, right? So when we're talking about limiters of VO2 max, we're talking about the various different places along the cascade of that transport that can interrupt or ⁓ prevent

the maximal value that we could attain. And if we know about those, knowledge is power, if we know about those various different limiters, we can make sure that we are checking our own training and practices in terms of how well we're working towards that. So last lecture, as Paul said, we really talked just about the lungs as the limiter. Today we're gonna move into the heart. Remember the heart is probably, exercise physiologists,

they often think that the heart is probably the main limiting factor. In other words, the faster or with the more pressure that you can pump blood around your circulation, the better off your VO2 max is gonna be. And there's a lot of data that suggests there's almost this one-to-one relationship between your maximal, what we say, cardiac output. That's the maximum amount of blood that you pump in a given minute.

You know, guys like, you know, I would always say Lance Armstrong, but whoever, right? Name your ⁓ hero athlete. They're typically up there. What's that? Lionel Sanders, there you go, yeah. Yeah, name your famous athlete that you just, you you idolize, right? They're sitting up there around 40 liters a minute, right? So that's the maximal.

Lionel Sanders. Lionel Sanders.

you know, cardiac output. ⁓ So, yeah, and you know, a lot of us can't get to 40 liters a minute, right? We might be, us mere mortals are probably sitting around at maximal exercise. We're probably sitting around maybe 25. ⁓ And you know, just sitting, so us sitting here doing the podcast, we're sitting at five liters a minute. So that's, yeah, we have five liters of blood and we, and all of it kind of gets pumped around the body in one.

one minute ⁓ and yeah, but that's the more, bigger the capacity we can make that heart to do that job, making it stronger and more efficient, the better off we're gonna be with our VO2 Max. I'll start there.

What specifically is it about the heart that ⁓ sets the ceiling?

Your parents, first and foremost, they often say, choose your parents wisely. Genetic factors. But whatever you got, whatever roll of the dice you got, there's still lots we can do about it. That's kind of the good news, bad news kind of scenario there. ⁓ Yeah, so ⁓ I guess it kind of comes down to the one area of the heart called the left ventricle.

Right? And that is like the large chamber of the heart with the most muscles around it, most cardiac muscle around it. And it is doing the big job of, we call it the stroke volume. In other words, it takes a big contraction and the amount of blood that it pumps in one given beat is called your stroke volume. And of course your cardiac output amount of total amount of blood that you're pumping around is the stroke volume times the heart rate. So you actually do want to have

high levels of both, And the, like, because it's a product kind of factor, right? You can have, if you have both a high stroke volume and a high heart rate, you pump a lot of blood and you can get up towards that, you know, 40 liter per minute ceiling, if we want to think about that. But of course, when we age, I certainly have noticed my maximal heart rate dropping and dropping and dropping. And if there's anyone, you know, anyone else,

who's out there who has monitored this as they've aged ⁓ as an individual. It's quite fascinating. They say you lose about one beat per minute per year. And that is just, ⁓ I don't know, it's an aging factor. Why does that actually occur? For whatever reason, you can't engage that sympathetic nervous system, fight or flight, as much, which engages that max heart rate to the high levels. Like for myself, I know

I remember when I was like 21, 22, I used to have a max heart rate of 206 and now it's probably sitting around 178. So, you know, and yeah, it's still up there for an old fellow like myself, but it's definitely come down, you know, almost 40 beats a minute in my, how many years? Yeah. 35 years, so yeah. Ouch.

No.

you

So can the training that we do change an individual's cardiac limitations on VO2 max or is there a hard physiological cap due to genetics ageing like you just mentioned, heart disease, et cetera?

oh yeah, no, you have a good level of control, not complete control. You can't stop farther time, but you can slow farther time with healthy habits. And exercise is one of those key habits, right? Exercise is going to slow the overall decline in VO2 max. That's well established, so we know that from.

a lot of studies and literatures and case studies that if you continue to do things on a daily or every second day kind of basis, consistency remember, then you're always giving your body the signals to tell it not to slow down. Don't lose that cardiac output. Conversely, if you're just getting off the couch and you're just being introduced to exercise for the very first time.

No problem too, you can join the club right away by just starting to do something right away. So you give your body the signal to adapt. So it's all about that signal, the appropriate signal, stimulus, whatever you wanna kinda call it on the right day, not too much, not too little, but just remember you're doing whatever you can do to ⁓ prepare yourself for the next session, right? So the most important session is the next session, but that consistency of training.

it will continue to tell your body to adapt.

What about inefficiencies of how hard or efficiently your heart is pumping? For example, if you have structural problems with your heart, like the valves are leaky. Because if you have a leaky valve, some of that blood that is being pumped to your circulation kind of like trips back down.

Mm-hmm.

That's right. Yeah, your stroke volume will all of a sudden be inhibited or lessened. And really, it gets a pressure problem. Just imagine it just as a mechanical system. And if all of a sudden we have a, if one of the valves is not completely closing and it's leakage, so all of that nice contraction that we've developed with our training or whatever,

the start effect stroke volume.

it's just like it pushes in the direction that we wanna go, but a little comes out the back, right? So basically you're all of a sudden lowering your blood pressure, your systolic blood pressure, right? So you remember, you go into the doctors, you're gonna potentially get your blood pressure measured and you get like your systolic over your diastolic, know, might spin out a number like, you know, 120 over 80 is a standard measure. So that 120 is the...

the beating pressure whilst the 80 is the diastolic or the relaxing kind of pressure, right? So that 120 is kind of compromised all of a sudden. Less pressure, less ability to kind of pump that blood around the body. yeah, that is a, and again, that could be a challenge. yeah, getting your blood pressure measured is not a bad idea.

Hmm.

the relationship between VO2 max, I mean, we're gonna take a little divergence here from your heart specifically, but the power and pace that we can produce at VO2 max, what's that relationship? Is VO2 max?

link to the power and pace you can hold at VO2 max.

let's just use the Athletica power profile that Andrea has kind of created with our, and that's basically your zone five. And that is the, you know, we use that, you know, we use a marker of your five minute maximal power output.

on your, if we're just gonna talk like the cycling context, say for example, right? So the higher your VO2 max, the higher that number potentially could be. Of course, if you haven't done an all out effort over those five minutes, then it's the data isn't really solid and you can't really pay attention to it as much. ⁓ AI coach should be telling you that we need some efforts in that region.

it's completely, we know it's completely VO2 max related. So that's why ⁓ the number that you get in there in terms of your all out max mean pace or your maximal mean power is very significantly related to that. It relates to the amount, your total VO2 max. And again, linking back, we mentioned that there is this link between the VO2 max value and the maximal cardiac output value. So we're...

Thanks.

We're drawing

a lot of different lines. There's lots of nuances and individual differences across these, in terms of a non-invasive measure, it's a really good litmus test or marker of where your VO2 max sits, is that five minute max mean power.

So if somebody has a high VO2 max, lack in economy and efficiency, that means that they are not able to tap into their VO2 max and like the ceiling is lower. they, yeah, okay.

Correct. Correct. Yeah, and they're probably, I mean, I'm

guessing that I probably fell into that bucket as a young athlete myself. I didn't do enough volume training to be able to, you know, I had the very high VO2 max. I think I was tested at 73 and, you know, could definitely crank various,

Wow.

performance is out in the sort of shorter duration, but I didn't have the coaches and knowledge to know that I needed some training volume. A lot of that 80, the 80 of the 80-20, I need more of that in my diet because that increases what you just mentioned, Marjaana which is the efficiency and the threshold. Those are the other two factors. Like when we look at performance, ⁓

physiologists often say that there are three key markers that go to your endurance performance. ⁓ Number one is VO2 max, which we're talking about in this series. Number two is your so-called threshold or fractional utilization of that VO2. And in the case example you just gave, Marjaana, that would be probably low in that individual. And then number three is your economy or your efficiency.

And again, that would also potentially be low. And the solution for that is a higher volume of training so that you can continue to grab a greater fractional utilization of that VO2 max. So the VO2 max number is still important, but it can certainly, it's not the be all end all in these different contexts.

So let's take somebody who is new to endurance training, has high VO2 max, hasn't done that big volume yet, has ⁓ great potential, but they like that go hard or go home attitude. And they come to Athletica and they set their daily constraints and say, hey,

top 10 hours, I can't do anything more. Eventually they're gonna meet their ceiling pretty fast unless they do a little bit more. Is that what you're saying?

Generally speaking, although, you know, we saw Sammy Inkenen, you know, did has done it on 10 to 12 hours, right? But his quote, you know, he's done things a little bit differently. His sessions on his weekend would be quality and ⁓ of a sufficient sort of duration ⁓ that he wanted to kind of perform at, right? And just for listeners not aware, Sammy I can is ⁓ the CEO of Virta Health.

He rode, he was on the Training Science podcast. He rode a boat with his wife from Los Angeles to Hawaii, which was unassisted and he ate nothing but fat just to prove it could be done. And he also holds, or he at one point held the record for the Kona age group. He won the Kona age group at one point. And he did that on, you know.

between 10 and 12 hours of training a week just to prove also that it could be done. But every session was kind of quality and race specific. So it was an intensity ⁓ biased sort of plan. So it certainly can be done.

Plus I wonder if he had some blocks of high volume training at some point, which would help. I don't know. Yeah.

You'll have to ask him. You'll have to ask him.

Can

you go back and explain what you mean by efficiency and economy? know that they're technically two different things, but let's just go back and make sure that our listeners understand.

Yeah, so economy of motion is kind of like how far you move in any given, for any given metabolic ⁓ energy. So it's like, you know, if your stride length is all of a sudden longer for the same output or energy, then you're more economical ultimately. and you can do, and a lot of times that's why the, you know, the longer the, sorry, the

higher volume can kind of elicit that adaptation where you're almost getting greater, what do call it, a little stretch shortening cycle. So basically your legs can be a little bit more like elastic bands and they're bouncing longer for each landing and takeoff. So you're all of a sudden now more, we say your running economy is superior.

because you're able to ⁓ metabolically burn low amounts of fuel at a set power or pace.

The heart as a

Sure.

does that matter in terms of different sports? Is the heart a limiter differently for cycling, running, swimming, rowing?

⁓ Good question. think it all, think it's, you know, there, I believe there, there can be like an entrainment factor that they've sort of found for things like that are, you know, I guess sports like rowing, like, like running. And when I say entrainment, it's like this, it's the entrainment, it's the cadence and the pulse and the flow of how the body kind of syncs up when it's taking, you know, a

what we call a duty factor, right? Like a stride length and a contraction, you know, in any context, like a rowing motion, right? You think about it, especially at high rates, you have to coordinate this whole ⁓ movement. Cross-country skiing, Marianne, I like imagine that, right? Like you're even at like high rates, right? Like you've got to coordinate the whole system. And same with running too, right? Running at very high rates.

got to coordinate all these sorts of systems. So yes, there are these little nuances between sports and ⁓ VO2 max, but in general, the principles are all relatively ⁓ interlinked and ⁓ they tend to be similar.

I want to double tap on that. I think this is a good example of VO2Max and economy, because a lot of sports are highly technical, cycling is pretty straightforward. Like anyone can ride a bike. But if you take cross-country skiing or swimming,

Hahaha.

Mm-hmm.

So let's take Paul and myself. I grew up skiing, Paul grew up swimming. So is it safe to say...

Me? No. No, I grew up

⁓ running and cycling. Yeah, bad swimmer.

Doing everything. Okay. Running and cycling.

But not cross-country skiing. But our VO2 Max, we haven't been in a lab, but is similar, right? But if we tow the line on a cross-country ski race, because I have the technique, but Paul, I don't know, you didn't come skiing with me, so I don't know about your technique. I just hear rumors. ⁓

No.

Read between the lines, MJ.

Yeah.

It's pretty bad.

So if we toe the line with our similar VO2 max, but my technique is better, I'm more efficient, he's gonna eat my dust or snow.

Yeah, I'm gonna eat your snow, that's for sure. Yeah, I'm not even gonna try. Yeah, that's like, you've got the motor pattern of cross country skiing dialed in from years, you know, as a kid. ⁓ But yeah, it's, and I don't, so ⁓ yeah, but you haven't taken me yet on cycling yet, MJ.

Exactly.

These are fighting words.

Mm-hmm.

Yeah.

Nope.

Yeah. Yeah.

You still got some work to do this summer.

The only other thing I probably should add on to Paul's question was when we talked to sport is the body position and how that affects it as well. So we know that, and this is due to almost like the body weight ⁓ issues and the pressures and ⁓ even in the context of swimming, it's like the hydrostatic pressures too, right? So imagine you've like, we've gone from

cycling or sorry, we've gone from running, we've gone to cycling and then we go to swimming, right? We're kind of going erect to horizontal, right? Across that. And there tends to be a difference and we see this in athletics as well, even in maximal heart rate or critical heart rate, where we've got the highest with the runners and we've got the lowest with the swimmers and the cyclists tend to be somewhere in the middle, although they can be up, you know, in experienced cyclists, they can be a little bit closer to the runner.

So, and I think this kind of relates a little bit to the body positioning where, you know, at high intensity and yeah, hydrostatic pressures and whatnot. So yeah, where it's like the, can think about it, just like, let's just look at running versus swimming, right? In the swimming context, the heart doesn't need to beat as fast and it's not pushing against gravity as much.

anymore, right? It's just pushing sort of straight out. So it can do all the work to supply the body with oxygen at a lower heart rate, a lower maximal heart rate compared to the runner who's at VO2 max screaming down the highway and has to really push against gravity and the heart rate has to probably beat a lot faster.

And that's generally what we see across different athletes and the same athlete across the different exercise modes, say the context of the triathlete.

Is that why runners tend to have, you know, the other endurance zones tend to be higher with heart rate with respect then to, to cyclists.

Exactly.

Absolutely. And it's why we need, you know, different zone targets, right? So again, you go to the overview tab on Athletica and you click through, if you're a triathlete, you click through the different exercise modes, you know, you will tend, and these tend to be taken from your data and your historic data, although of course you can manipulate these if you feel they're off or you know your own historic values, you know what they should be at, you can change these.

But if you just let Athletica do its thing, you should see these ⁓ calibrated ⁓ in accordance with ⁓ whatever the data shows. Of course, that data can be wrong, garbage in, garbage out. So be careful there. And sometimes we have to find the errant file that's sitting in there to delete that, whatever. But yeah, it generally shows that pattern if things tend to be aligned.

notwithstanding lots of individual differences. So it's not a BLM doll.

Can we talk about the individual differences? Sometimes, let's just throw in a 50 year old male has super high max heart rate still. So it's not going down with age like most people. They are outliers, right?

Totally.

So how should, if you don't have lab tests and you're coming into Athletica and you feel like your zones are not set correctly and you're one of those outliers that might have a super high...

Max Hot Raid, Zone Stone Feel Right. What do we do?

To me, and I mean, gosh, we get this question every day, MJ, on the forum and otherwise. And to me, the key solution, and I know this because ⁓ I go through certain examples with Andrea ⁓ often, and the solution is we need a maximal test. So we need an FTP test.

20-minute all-out, we need a power profile test, or we need a 5K run test, or we need a critical power swim test, or any of the rowing tests, right? So we need to, or a race. If you've had a recent race, you can usually go back to that race also and see what that critical heart rate was probably sitting at. we kinda need, if we don't have all-out ⁓ periods of work,

you know, again, back to GIGO garbage in, garbage out. don't, know, Athletica can't know the unknown if you haven't given it that, that Intel. So you got to do, you got to do the tests and a lot of people don't like to test, right? And so we need, but we need, we need some hard efforts. And usually AI coach will tell you that too, especially on your profiles. If you're, if you're shy of, of any ⁓ key, key areas in your profile, it can usually pick those out. So, ⁓

you know, if you're wondering, ⁓ maybe a first point of call is to consider, is to look on your profile, in your charts, look at your, you know, your power profile, your pace profile. And what does AI coach say in there when you click on the, on your avatar in the bottom left-hand corner? Is it recommending that you, that you might be short of some, all out durations, you know, say for example, 30 30s, it'll tell you that often or.

three to five minutes, two to five minutes, ⁓ or something longer. So try to give it that data first. If you can afford the energy and the excitement and enthusiasm to do an all out test, yeah, try to give it that data. And then if it still doesn't update, then come see us, come talk to us.

And does one or two heartbeats ⁓ matter? Why not?

No, one or two heartmates definitely doesn't matter.

Well, I just, think you're, I call it splitting hairs, personally. And again, I'm throwing my coach hat on, right, with you guys. And I just, as a coach, I don't care about one or two beats. That's just too binary. That's just like, it's not, you know, there's gonna be errors, ⁓ you know, natural errors in heart rate readings, in equipment.

⁓ So yeah, I feel, this is why know, feel always trumps this. We're using the tools, and even Athletica just as guides, so, but I don't get hung up on one or two beats, MJ, not me personally.

Heart rate can vary so much day to day based on what you've eaten, slept, life stress.

Yeah,

yeah, for sure. And the tool that you're using too, right? Let's be honest that we know that chest straps, say for example, tend to be much superior than the wrist-borne sensors. I know I get that from mine, right? Like they've come a long way. I give Garmin and others a lot of kudos for the work that they've done. Even in the pool, I can't quite believe how, when I look at my heart rate when I'm swimming, just with the wrist ⁓ sensor.

Hmm.

Wow, pretty good. I'm like, I'm knowing my heart rate for so long. I'm like, yeah, that's actually what I would predict it would be at. I can't believe it. So they've really come a long way, but nevertheless, you will still often see poor heart rate readings if you compare a wrist-based session to a chest-based session. So check your batteries. Batteries will go. They need to be updated. Check your strap as well, too. They...

you

Thank

know, over time they disintegrate and you need to buy a new one. They're not too expensive, but it's a good thing to kind of check on every three years or so, depending on how much you use your heart rate strap. So yeah, that's important.

What specifically should we be doing in our training to improve the cardiac function and improve our VO2 max? What kind of training should we be doing?

Yeah. Well, again, my bias is the athletic training is very good for enhancing this, of course, and within that, you will find ⁓ an 80-20 balance in general. So you want to have the bulk of your training in the aerobic cardiovascular, aerobic development, ⁓ foundational work. And, you know, we've had multiple podcasts before when we've talked about, we know the importance of that.

base foundation for delivering fat oxidation capacity and adaptation power, adaptation energy when we do the HIIT sessions. The foundation of that 80%, the 80-20 kind of percent aerobic, you know, below threshold, know, below first threshold is going to facilitate the adaptation when we do the HIIT sessions, the Via2Max work.

So it's all about the balanced profile that is going to enhance your VO2 max from the cardiovascular standpoint the most. We really sort of need both, Paul.

from your previous life as an exercise physiologist, how fast can you improve and how much can you improve VO2 max?

Yeah, good question. Well, it's interesting. There's some little brain cell went to an old paper and it was, and a story about that actually. I think was, Hickson was the author and it was earlier on, but basically what the researchers did was they took a group of ⁓ completely untrained ⁓ students.

And they said, come with us, we're gonna train you hard for, I forget what the duration was, but it was 12 weeks or whatever. But they were sitting down around 40, and by the end, they had almost all of these young students up around over 60 mils per kg on average. So was quite remarkable. If you are young and healthy, how quickly and how high it can actually go.

Wow.

So yeah, I mean that's the first classic paper. Of course, this is a group of students who are, know, they're 20 something, right? So they should have generally a great capacity to adapt at that age. Now, everyone listening to this is going to be an individual with their own backgrounds and that could range from being sedentary all your life to having some good sporting background and healthy upbringing. So it's just, it really will depend.

but the increase can be ⁓ quite large. And importantly, we all can adapt. We can all improve our VO2 max. ⁓ yeah, everyone, just, again, the training needs to be sensible, individualized, consistent, and progressive, yeah.

So do you think you could take your 54 to over 60? If that was your goal.

Ooh, no, think I...

Well, my goal is 55 if I'm... I guess I'm just an open book right now, right? Like, my goal is 55. Yeah. My age is 54 and my goal is 55. And I'm currently sitting at... Just prove it. I'm currently sitting at 50 in the wintertime. And I'm just using the Garmin system, but I'll...

Yeah, you are.

It's just a number. When I get enough consistent sessions and writing down, it tends to track and follow. So that's how high it was ⁓ last year. So going for one more goal. see what we can do. It might be a crash and burn, and that's OK. I gave it a go. It's getting hard, if I'm honest. ⁓

to be continued.

So what are our final thoughts about your heart as a limiter for your VO2 Max?

MJ, any comments?

Take care of your heart. Keep it pumping.

Mm-hmm.

Yeah, and we didn't even go into any of the AFib ones, but we've done that one before, right, Paul? Yeah, we're just talking about the general limiter of the VO2 max. So if I can kind of think about summing it, it's first and foremost, ⁓ exercise physiologists will say that heart is number one in terms of the factors that are going to be potential limiters. Remember the four that we've talked about.

Yep, yeah we have.

We talked about lungs last time, heart, blood, and then periphery or metabolic machinery. The heart is number one. So if you can deliver that oxygen, it tends to go up, gets sucked up. So it's probably the key one to think about. Number two, ⁓ we know that we're talking about cardiac output. Cardiac output is the total amount of blood that is pumped in a given minute.

This can be as high as 40 liters a minute in the elite, 25 in us mere mortals, and it's sitting here at five liters a minute whilst we sort of sit around. And you want to kind of play with that. And what can you do to change it? Probably following a polarized training plan or a periodized plan with a period of base training and then followed by build phases. And just kind of like what I'm talking about and going to do.

to try to keep it up there. It will fluctuate during the year and that's okay. That's another important kind of consideration. So yeah, that's, you need the balance of the ⁓ high volume, low intensity training, aerobic development training, and then you couple that with the specific HIIT training.

that specific hit training is really important because all of a sudden the whole system is at max, right? So it's like all of a sudden you have this high time at FIA 2 max and that is probably the key signal for going to the next level. So I'm at 50 right now, my next goal is 51, so I want that high intensity effort to be able to...

Increase that one to the next level and on and on it goes and keeps like stepping up so I think those are probably the the key factors, but But yeah a heart is key

Do we care to talk about spicing it up a little bit with heat training and altitude?

Yes, but I think we should save that one for the next lecture, Marjaana, because that couples probably best with the blood and the periphery. And then we can kind of talk about that one in there. But that's a great segue for the next one coming up next week.

Nice.

That was not planned.

Thanks for exploring the path to peak performance with us today on the Athletes Compass podcast. When you subscribe, you'll ensure you're always tuned in for our next journey into endurance, mindset, and performance. And when you share this episode with a friend, teammate, or coach, you'll be helping them discover new ways to level up their training and life. Take a moment now, subscribe, share, and let's keep this endurance adventure going together. For more information or to schedule a consultation with

Check the links in the show notes for Marjaana Rakai and Dr. Paul Laursen Paul Warloski and this has been the Athletes Compass podcast. Thank you for listening.