We know we need to increase the strength of the left ventricle as a starting place. If we do that, that will allow or actually produce and result in an increase in stroke volume. So, what does that mean for training?
Well, fundamentally, outside of things like exercise technique and timing and nutrition and all that other stuff, if we're just talking about the background physiology, we have two avenues or areas to push on to improve our VO2 max. We have our stroke volume and our a-vO2 difference. So, there's a lot of ways we go about improving both of them.
I am of the opinion that you need to train across a wide spectrum of exercise intensities to optimize both factors. If you in fact look at classic training logs of endurance athletes, going back to even what we know about Oscar's training, they are typically going to spend something like 70% or so of their time at a low intensity. What's that mean exactly?
Mm, depends on the athlete, but you're probably talking about something like between 60 to 80, maybe up to 82% of their heart rate peak. Most of their time is there. I'll explain why in a second.
Then, you've got another additional maybe 20 to 25% of your time being spent at a moderate intensity. Mm, typically something like, again, 82 to 90 or so percent of your heart rate peak. And then, three to maybe 6% of the time at the remaining higher heart rate.
So, this is 92, 93% or so plus. The reason I'm giving you kind of rough guidelines there is every scientific paper has those zones, if you will, a little bit differently. All kinds of different endurance coaches historically have set different landmarks and so, there's no exact numbers there.
And so as a very rough guideline, I think it is very safe to assume some split like that should be highly effective at improving your VO2 max. What's that mean in terms of exercises? Well, actually it's entirely up to you.
VO2 max is, remember, dependent upon how many milliliters of oxygen per kilogram of muscle per minute, which means the more muscles you utilize, the higher the VO2 max is. If you were to go to get a VO2 max test done, and let's say you were not specifically trained on like a bike, if you were to get that same exact test done on a bicycle versus a treadmill, where you're running versus cycling, the score on the treadmill is going to be about 10% or so higher than it is on the bike. And that's simply because there's a small increase in the amount of muscles involved when it comes to running versus cycling.
Now, if you are specifically trained on the bike and you cycle a lot, that may not actually be the case. And in fact, highly endurance-trained folks on, cyclists, rather, will score higher on a VO2 max test on the bike than they will on a treadmill. But that really is now coming down to test specificity, efficiency, like all the things that are, that's not what we're trying to talk about here.
And so, generally, the more muscles involved, the more oxygen being utilized, the higher that VO2 max. So when it comes to training, we want to think about the same thing. The exercise mode, I don't want to say it doesn't matter.
It is relevant, but you have unlimited options. If you want to bike or swim or cycle or row, that's great. If you don't like any of those traditional modalities and you want to use something like an assault bike or pull a sled, run uphill, drag something, those are also incredibly viable options.
It's not the exercise per se that determines the adaptation, it's the application of the exercise, right? The body works and physiology works on a principle called the SAID principle, S-A-I-D, which stands for specific adaptation to imposed demand. So you put a demand on a tissue to bring in and utilize oxygen at a high rate, it will adapt to that specific demand.
So challenging your muscles continuously to bring in and utilize oxygen at a rapid rate is all fundamentally that needs to happen for you to improve that. And so again, the mode of the exercise is not that big of a deal. If you are new to exercise, I would generally recommend you being careful of exercises that involve a lot of eccentric action.
So, jumping and landing, because you're going to get really sore really fast. But if not, feel free to choose whatever exercise modality or a combination of them. Switch it up a little bit, Do some cycling, do some running uphill, jump in the pool.
Really up to you. The intensity in which you do that is more like what I just explained. As I apologized at the beginning of the program, I, earlier in my life, grossly underappreciated the cardiovascular system as a whole, and I certainly underappreciated the importance of low-intensity exercise.
I'll also be candid with you here. I am not as fond of zone two exercise as some other folks are. I certainly don't think it's bad.
It is good for you. I just don't think you need to be that worried about what exact zone you're in. You want to be something probably in that lower intensity, 60 to 80-ish percent of your heart rate.
I don't really care where your millimolars are. In any of those low intensities, you're going to be challenging the ability to bring in and utilize oxygen over a long period of time. Look at any amount of research on that.
It is very clear. Steady-state, lower-intensity exercise, especially over time, six months to a year, is generally going to improve VO2 max, probably upwards of five to 10% depending on the person, the training history and other contexts like that. So it's very, very effective and something I have absolutely incorporated more and more into both my life personally as well as my coaching practice.
So, really important to do that stuff. On the other end of the equation, you can do things at an extremely high intensity for a short about. Depending on the study you want to pull here, you can see things like high-intensity intervals.
This could be a combination of 30 seconds of maximal exercise, resting 30 seconds, and repeating that anywhere between like four and 12 times can equally improve VO2 max, if not greater and more so than your steady-state exercise. There's a lot more context that go into that. It's not necessarily meaning high intensity is better.
There are some significant downsides and concerns with only doing high-intensity exercise, another thing I've changed my opinion on. And so, I think we want to use high-intensity exercise. There's clear benefit there.
It's fundamentally different, though, than low-intensity exercise. So, we're challenging a different part of the system, which is why I'm going to argue you should be incorporating both most of the time. It doesn't have to be always in all of your training, but you wouldn't want to leave either one of these things entirely off if the pure goal here is to maximize VO2.
The reason is, when you do something at a higher intensity, the point of failure in the tissue becomes different. So, extending my ability to move at a lower or moderate intensity for a long period of time is challenging different aspects than it is when I ask it to introduce a tremendous amount of fatigue. So, I'm now into anaerobic metabolism when I'm going really hard and really fast.
I can't use oxygen, so I'm building up a ton of byproducts. pH is being disturbed, potential damage is happening, other things are occurring, CO2 is getting extremely high. And so, enhancing my ability to deal with that is a similar thing in terms of increasing mitochondria biogenesis.
So, more mitochondria, higher-functioning mitochondria, larger mitochondria, increasing aerobic capacity. All of these same things occur. And so, again, I don't want to make the argument that one, higher intensity or low intensity is better than another.
I think you should do both. I will make the same argument for moderate intensity. While that isn't as specific and precise in terms of what it's challenging, it's reasonable to build some of that into your equation as well.
Another thing you're going to find commonly in the research is a longer about of intervals. This is described in a lot of different ways. A good friend of mine and an expert in endurance physiology, Joel Jamieson, has talked a lot about high-intensity continuous training, HICT.
If you're not familiar with that stuff, I would encourage you to look it up. It's very, very effective. Lots of different things and tools we can pull out here.
One example would be something like, let's go with a classic runner, who would do something more like one mile repeats. So, run a mile as fast as you can. This is going to take most folks, you know, six to eight or nine minutes or so.
However long it takes you to run that mile, rest that same amount of time. So, it's a one to one work to rest ratio. So six minutes of running, six minutes of rest, and then you repeat that again for a total of two or three or perhaps four repetitions.
That's a very long workout and the average person would not be able to do that. But those of you that are not average, that are good to high to strong performers listening right now, that's absolutely within your capabilities and in fact, you've probably done it before. It doesn't have to be that extreme.
You could use shorter durations, say two minutes, three minutes. Four minutes is a very, very common one you'll find in research. So four minutes of all out exercise, four minutes of recovery, repeat it again two to four times.
What's critical to understand here is these work when you're actually achieving a maximum in that time domain. So, you can't do four minutes at 70%, rest for four minutes and do that again. That's going to burn you some calories and has other benefits of just making you feel better today and some other stuff like that.
But in terms of VO2 max, it's probably not the most efficient thing you can do. So to summarize all of that stuff, spend a good amount of time at a lower intensity. That's going to drive efficiency, a common adaptation there, since it's going to be the highest activity you can do to maximize utilizing fat for fuel.
You're still going to be burning primarily carbohydrates, don't get that confused, but that's the best way to burn some fat. So, this is typically associated with higher metabolic efficiency, getting better at using fat as a fuel source and things like that. It's also easy to recover from.
It's not going to change your autonomic nervous system that much, so you typically don't see big drops in HRV scores. We don't really see as much over-training or non-functional overreaching, elevations in respiratory heart rate, other signs of hunger or fatigue, not wanting to train. Things like that doesn't really happen when we spend time at lower intensities.
Higher intensities are phenomenal. Really, really, really time efficient, but they've got consequences as well. They're going to be entirely or mostly anaerobic, which is okay too 'cause you'll still use the aerobic side of the equation to recover from that.
So, super important. But there's a price to be paid there. People can run into problems and you're more likely to see issues with those metrics I just described.
If you're doing too much intensity too often, especially if you're combining this with a normal stressful life. So you're doing this kind of exercise, then you're going right back into your day job. You're having difficult meetings, even if they're exciting and happy meetings, you're thinking hard, you're working, you're getting back to forth, and you're in a kind of a long, high-stress environment all day.
Really, really challenging on the system to be in that high of a stress at all times. So other ways you can mitigate that, we can talk about those in future episodes. But just wanted to say, while high intensity exercise is very time efficient, it's not necessarily a free pass either.
Low intensity, not a free pass either. It's going to leave things on the table that you're missing. So to round all that up, again, I would recommend a combination of lower intensity, moderate intensity, and high intensity training.
The mode of the exercise in terms of what you choose, bicycle, kettlebells, circuit training, it's entirely up to you. Spin class, whatever you'd like to do. Frequency can be as high or as low as you'd like.
There are plenty of studies showing kind of the higher intensity stuff done two to three times per week can improve VO2 max. But you can also do the lower intensity stuff every day or a combination. So really, you can modify this based on your lifestyle and what's going on.
And finally, rest intervals, they're not incredibly applicable here. In fact, we've already baked them in. If you're not doing intervals, there is no rest interval.
If you are, we typically look for something like a one-to-one work to rest ratio. But you're welcome to do two to one, one to two, or any combination of that. If you train appropriately, and of course you've got all the other factors like your nutrition and sleep and stress management under control, it's not unrealistic to expect a 30 to 50% improvement in VO2 max after six to 12 months.
You'll find plenty of studies that land in that ballpark. The rate of increase obviously goes down as you become more and more trained. Now, candidly, you don't have the ability to improve your VO2 max probably as much as you do something like your strength, but you can improve it significantly nonetheless.
So, you will find plenty of studies showing even a 10 to 20% increase in highly-trained individuals after a year. In untrained folks, that probably takes about half that time, so 10 to 20% improvement in four to six months or so. So if you know where you're at right now, you train appropriately, fairly consistently, again, those are reasonable numbers to expect after a half a year or so of training.
And as we understand it, the biggest limiting factor at this point is probably the time needed to fill the ventricles back up with blood.
