maxim809 wrote: ↑Wed Apr 14, 2021 4:19 am
"Muscle recruitment required for the demands of exercise = maps to oxygen = maps to VO2". For example, as a thought-experiment it seems very unlikely that one could reach their lifetime potential VO2max by training exclusively in hand-cycling. But perhaps this is a bad example because running and cycling are closer to each other on the demands of the exercise.
Good points but if your overall premise (that running inherently demands greater muscle recruitment) were in fact true, there is no way that a person could achieve their maximum heart rate on a bike, which we all know is untrue. Try sprinting up a 8% grade at 120 cadence you will be very close to MaxHR!
The implication here is, yes, running uses a broader range of muscle groups. But the body's overall workout, and by connection energy and oxygen demands, are all limited. In other words, you may use more muscle groups, but you are not using every single muscle fiber in those groups, and they are not being worked at full capacity. Put another way, just because you use a broader range of muscle groups does not mean that you can suddenly do more work. Using more muscle groups may mean that you hit MaxHR and Vo2Max / Vo2Peak sooner, but eventually you hit your body's maximal work capacity and ability to uptake oxygen, hence, you derive your Vo2Max / Vo2Peak.
Here's a real world example. Imagine bending over to pick up a basketball. This series of motions is a "full-body" movement that uses a large number of different muscle groups to execute. However, will you be able to achieve Vo2Max by repeatedly picking up a basketball? No.
So this begs the question - do we really understand what Vo2Max is? In layman's terms (combining elements of Vo2Max and Vo2Peak), it's the point at which your body (as a whole) is doing the most amount of work it is capable of doing. But we can't measure this directly - we can't possibly count all of your muscle fibers, capillaries, mitchondria, biomechanical efficiency, muscular endurance, etc., so we instead indirectly measure the maximum amount of oxygen that your body is able to consume to produce the maximum amount of energy your body is capable of producing. In otherwords, your oxygen uptake serves as a corollary to your maximum exerted effort. And by connection, a higher Vo2Max means your maximum exerted effort results in the production of more energy and work than an equal effort by someone with lower Vo2Max.
Sort of ironically, and very funnily, when researchers were trying to figure out why runners' Vo2Max was lower, there was a hypothesis that this is because the running motion features recoil/springing action of the legs, and therefore that running may actually be an easier activity than cycling.
Of course this was debunked (runners have no problem reaching maximum heart rate so they are definitely capable of doing maximum effort!).
On XC skiing, I'm really really glad you flagged this issue! (I was hoping somebody would because I don't want to spoonfeed you all). XC skiers are also heavily researched.
You know that 80:20 rule? Yeah, worldclass XC skiers don't follow this at all. They do almost all of their training at low intensities (and they do a ton of training). They spend around
1%!!!!of their training doing intervals (caveat that 5% or so of their training becomes high intensity during specific blocks in the race season). They also devote a good amount of time in the gym.
They train betwen 15-20 hours a week (with I believe 1 long session a week). They do two-a-days. They also follow the 45-90 minute block strategy. They have amazingly high Vo2Max with very low intensity training, and are incredibly fit human beings.
All backed by modern recent research.
And to the gentleman who previously said stuff like "this research is a waste of money, I wouldn't spend my money on this research, it's a waste of time" - all this ties into the big picture. Whether you're an elite athlete, a gym teacher, a healthcare professional, a human health policy government official, you want to know how you can elicit the most efficient and effective physical benefits from exercise. To do this you need to make a hypothesis and test it, and then refine and refine and refine with further studies which go down to an increasingly granular level. You know how in gym class they made us run laps, do shuttle runs and play basketball, yelling at you to go faster and stop being lazy? Is this still advisable from a physical fitness perspective?
So, what do world class XC skiiers and World Tour riders have in common? They do a ton of low intensity aerobic exercise. What do they do that is different from amateur cyclists? Or elite marathon runners? Or recreational hobby marathoners? I contend that in the US, most aerobic exercise is conducted at around 140-160bpm for males...too fast while at the same too slow! And this level of exertion was taught to us by naughty gym teachers and Rocky movies as being the key marker of "exercise." No pain no gain! Right? If you're not sweating and grunting, you're not exercising! At the same time, Kenyan marathoners are laughing and making jokes barely breaking a sweat while on their "easy" 12 mile training runs at 5:30 min/mile pace. And everyone is shocked that the US, with all its funding and resources, has continuously underperformed at endurance sports for the past several decades. But hey, someone will gladly sell you an interval training program for the low price of $149.99 that will surely help you take your training to the next level!
But he put us on the right track.
