VO2max. What actually is VO2max? It is the maximal amount of oxygen an athlete can take up during hard exercise. Coaches but also researchers have used this metric to assess how aerobically fit a person is.
Endurance athletes have reported the highest VO2max, while strength athletes or sedentary people have typically lower VO2max. But what about CrossFit athletes? They do strength and endurance at the same time.
They are super fit so they must have a very high view to max too right? I did a study in collaboration with the University of Basel to find out. In that study we measured the view to max of 60 well-trained and world-class CrossFit athletes.
In this video I will discuss why CrossFit athletes have a lower view to max than you would think. I will discuss the physiological reasons why and how you can use this information as a coach. or an athlete. Ready for it? Let's dig into it!
Hi everyone, I'm Gomar. I'm a researcher at ETH Zurich based in Switzerland. And for the last decade or so I studied the impact of nutrition as well as exercise on muscle mass and health. And now I want to provide some of that science back to you. you guys.
First of all what is VO2max? VO2max is the maximal amount of oxygen an athlete can take up right and it's typically measured in we call this a ramp test to exhaustion where an athlete has to run or bike or row always at a higher intensity until he or she cannot perform anymore or when he or she is completely exhausted and now we measured amount of oxygen the person actually can take up mostly by the muscles and you can see here that the oxygen uptake increases linearly with the intensity that makes sense right the more energy is needed to move let's say the pedals also the more oxygen is needed to propel the muscles and at the end so when the person is almost at exhaustion you see that you can reach a plateau this means that even though the intensity increases the oxygen uptake the oxygen uptake actually doesn't increase anymore and that is your true vo2 max you can also have let's say a vo2 peak we call this and that is just when there's no plateau it's just the the oxygen uptake reaches a typical peak and then it drops down because the athlete is exhausted so that's that's one that's how you typically define it and it all has to do with the thick equation so VO2 can be defined as the cardiac output, so how much oxygen you can deliver, how much oxygenated blood you can deliver to the tissues, times the arteriovenous oxygen difference. That's a difficult word for just how much oxygen the muscle can actually utilize or extract from the oxygenated blood that is entering the muscle. So that is always something you have to look at. Not only the heart, how much you can pump out, how much oxygenated blood you can pump out.
but also how much you can obviously use by the muscle. And that's an important point for later in this discussion. So Bengt Saltin, who is one of the most famous physiologists ever lived, he unfortunately died in 2014. He did a lot of super cool studies. So if you're interested in physiology and VO2max, just look up his work, Bengt Saltin.
And he did, already in the 70s, he did a study where he assessed the VO2max of different types of sporting or athletes, right? And they. have for example here at the top you have the skiing or the cross-country skiers the runners the speed skaters they obviously have very high vo2 max because they need to produce a lot of energy aerobically and here you can see they measured uh here five athletes and they came up to 80 milliliter oxygen per kilogram body weight so that's a relative way of saying how much oxygen someone can take up right so you're always divided by the body weight elite elite endurance athletes i have reported that's above 90 really the maximum of oxygen uptake. Then when you go down the line you see more less aerobic sports such as biathlon, walking, canoeing, ski alpine, running 400 meters some more the sprinters and then you also have a whole more at the bottom so where the VO2 max is quite low 40 to 50 would be wrestling, weightlifting or untrained people as you would expect.
Good so more combat sports or strength sports. So what about CrossFit athletes? That's always something that was in my mind because CrossFit athletes athletes they do a lot of strength work a lot but also a lot of endurance work and also a lot of let's say mixed work where they combine strength and endurance at let's say one session or even one workout what about their vo2 max must be quite high right let's see so we did a study in collaboration with the university of basel where we tested 60 world you ...was to well-trained...
crossfit athletes. I'm talking about games athletes, semi-finalist athletes and all quarterfinal athletes. So a good group of trained people, 30 men 30 women. And we subjected them to a battery of tests where we also assessed their body weight, their anthropometrics, their lung function and also how good their friend time was and their 1RM back squat.
But also we measured them aerobically, so with a mask, so testing their VO2max and their endurance capacity. capacity and also several strength tests. So typical physiological profiling that you could do in the lab with also other types of athletes.
I will put the link to this study in the description so you can read through this study because now I will only talk about the VO2max but we measured several other things. And what you can immediately see here is that we defined well-trained athletes as anyone who was in the top five percentile of the Open, right, but did not make it to the semifinals. That's important.
important and then the elites also were a sub cohort of people who made it to the semi-finals or the game so really really well-trained athletes right and then males and females you can see here that the elite crossfit athletes only had 56 on average VO2 max so that's we can call this moderate right like decent it's obviously not sedentary but it's also not the same as a well-trained endurance athlete the same for the women who had 51 on a relative basis for some was asking absolute VO2max was also not substantially high right so let's say a mediocre VO2max. So obviously this is one study right so I was looking at other studies in literature where they reported VO2max of well-trained athletes crossfit athletes and they all were sitting you can see here the studies at around 47 to 50 of milliliters O2 so it's not a very high VO2max at least not what is reported. into the literature which corresponds well to our study in very well-trained athletes. So the question is why do these CrossFit athletes have such a relatively low view to max? And before I go into this I want to talk briefly about a new platform we are collaborating with.
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And also we get a little kickback which supports the channel and supports the page. So if you're interested in Stri-V, just have a look in the link in the description. So why do CrossFit athletes have a lower VO2max?
There's several explanations. I have four of them that I think are important, but obviously they always intertwine and not one is separately determining. Good. First of all, if you think...
Think about the CrossFit, right? So the CrossFit Games 2007 compared to now are completely different. And I think, except for this year, but all the previous years, CrossFit was quite heavily strength biased.
Think about snatches. If you, at this point, cannot snatch 285 as a male and whatever, 190 as a female, you will not make it to the semis or certainly not to the Games. So you need to have a certain certain amount of strength, let's say 280 snatch, you don't want to be too weak. If you're too weak, you don't make it to the top.
If you're too strong, that's probably also not the goal of the coach and the athlete, because then you probably will have to fail or have weaknesses on the other part, for example, endurance. So always think about at the middle size of the bell curve. Good. So strength-biased CrossFit, that's one.
So that's one reason why top athletes or well-trained athletes don't have the same VO2 max. as an elite cyclist because obviously the elite cyclist needs much less strength and much more endurance capacity. This ties well with the second reason which is the interference effect.
Interference means basically that strength impacts endurance or conditioning or conditioning impact strength gains. I did a big video on this not so long ago which pops up above on your screen, it's also linked in the description where I explain how and what's the best way to Combine strength in endurance for hybrid athletes. So if you want to learn more about that, just have a look.
So interference, why is this important? If you are a CrossFit athlete, you have let's say 30 hours of training time per week, maybe a bit more, maybe a bit less, doesn't really matter, right? And you always have to divide your training time between endurance, mixed and strength. You always have to kind of combine them some way or another, on different sessions or in the same session, whatever, right?
While on the other hand, an endurance athlete, he or she can do nothing. 90% of the work in endurance and only 5% will be strength. So obviously on the long term, after five, six, seven, eight years of training, the endurance part would be much more developed in an endurance athlete compared to a CrossFit athlete, just because of the volume or the accumulated volume into one modality or the other. And that's important to understand because it's known from previous studies, and actually there's a lot of data about this, is that if you do concurrent training, which is basically doing endurance and strength in the same session or at least in close proximity certainly in moderately trained and highly trained athlete there will be some kind of interference where one modality will actually have some kind of plateau compared to yeah the other modalities this you can really nicely see if you have a look at the data from our crossfit study where i just talked about what we did here is we compared the results from our cohort of crossfit athletes to let's say real experts in the field.
For example the VO2max of our cohort of athletes, the CrossFit athletes had a VO2max of let's say 50 to 55 and then we compared it to the VO2max of elite cyclists. And here you can very nicely see that on the endurance side of things also let's say critical power and threshold power, so we're sitting at 75% of the values of elite cyclists in endurance sports. It's a bit less I'm not gonna say problematic or at least less interference in the strength part. You can see for example counter movement height Actually there the CrossFit athletes were close to the same values as elite weightlifters here I'm talking about the meals also for the females You see a similar pictures where mostly the endurance values are at least 10 to 15 percent lower than their female specialist their counterparts but the specialists and then you also have the strength parameters who are less affected by the interference effect.
Okay so that's quite interesting is that is something that long-term concurrent training would do. So back to our reasons. Reason number three is a little bit more biochemical.
Here you see a depiction of the muscle fibers and the pink lines here are the capillaries and obviously the capillaries are small blood vessels that provide oxygen to the working tissue or the muscle fibers and how it works is that the oxygen arrives and then it diffuses. diffuses towards let's say the middle or at least more inside the muscle fiber towards the mitochondria which then obviously use the oxygen to provide energy via the electron transport chain good so you have to think about it that the oxygen has to diffuse passively diffuse into the middle of the muscle fiber and the more capillaries you have the easier this diffusion goes so when you have an endurance trained athlete he has small muscle fibers relatively small it doesn't have big muscles muscles and a lot of capillaries. But then you also have a strength biased or more a CrossFit athlete.
We all know that CrossFit athletes, they are strong. They have a lot of muscle mass and there the capillary to muscle size or muscle fiber ratio decreases, meaning that the muscle size is bigger than the amount of capillaries. So the diffusion of oxygen is going to be more difficult for a CrossFit athlete than for an endurance trained athlete.
That's why. just the amount of muscle mass can probably interfere with the aerobic capacity of a CrossFit athlete. And then we have the fourth one and that is not really physiological but also an important thing to do to mention. There's also a method of testing.
What we did we put those CrossFit athletes on a stationary bike and we let them bike until exhaustion. Obviously CrossFit athletes sometimes hop on a c2 bike but they're much less familiar with such a movement. than for example a cyclist or a rower with a rowing machine.
A CrossFit athlete is much more familiar with burpees, snatches, pull-ups or thrusters. And I found a study that was recently published where they actually tested the VO2max of CrossFit athletes while doing FRAN, which is obviously we all know 21-15-9 of thrusters and pull-ups. And that is obviously something we didn't do yet and there is not a lot of data on it. It's...
We could use more CrossFit specific movements to test the VO2max of athletes and then maybe you would see much different results. For example a good way to test this would be from kind of dead by thrust. thrusters and pull-ups.
For example, you put on a mask as depicted here on the athlete and the first minute you let them do one thruster, one pull-up, second minute two thrusters, two pull-ups until exhaustion. It's similar as a REM test to exhaustion but with CrossFit specific movements. And if you would do such a test in highly skilled, highly trained athletes, you likely, in my opinion, would see higher VO2 maxes compared to what we just tested.
So the question arises, what can I do with that information? We know now that CrossFit athletes, because of the strength and also the interference, don't have the highest VO2 max ever reported, right? They have much less endurance capacity.
likely than elite cyclists or elite runners that's one so if you then go back to our study we actually tested if there would be a correlation between the VO2max of a specific athlete and their open rank so how well they performed in the open and here you can see certainly in the men there was actually no correlation literally zero correlation there was a very weak correlation in the women who which was statistically significant but it was not very strong. Good? So maybe VO2 max is not a super important determining factor for performance in CrossFit.
Indeed we actually found that anthropometrics, so how long your femurs are, how long your arms are, is much more important in determining your open rank as an elite athlete. That's something to consider. So height definitely plays a role here. So as a coach it might make more sense to not just focus on VO2 max or absolute or maximal oxygen uptake but rather on movement efficiency and using oxygen uptake during tests of movement efficiency for example if you have a portable oxygen analyzer right oxygen uptake analyzer you could do certain movements and try to improve the movement efficiency so that you can do the same amount of work at the lower oxygen uptake that would be much more useful for an athlete than just testing their maximal oxygen uptake which anyway doesn't really define elite performance.
All right that was a long one thank you for sticking until the end this was hopefully quite valuable for you if you found is interesting give us a like and also a subscribe it really helps out the channel. For me that was it see you in the next one ciao