It’s a too-common belief that VO2max (aka aerobic capacity) isn’t trainable. I recently spent 10 straight hours with some of the top coaches and exercise scientists in the world learning about aerobic and anaerobic capabilities, lactate/pyruvate dynamics, how one system influences the other, and how tremendously trainable both are, especially aerobic capacity.
Suffice it to say, VO2max is highly trainable, but like so many things, it has a ceiling. As you approach it, gains become far more minuscule in nature, but it’s still alterable.
And yep, there’s a huge genetic factor that determines the height of your capacity (you get this from your mom, by the way), but that doesn’t change the fact that it’s very trainable, and therefore detrainable.
I bring this up to point out that it’s self-limiting and a bit of a cop-out to just pin your performance capabilities, or lack thereof, on a low VO2max when it’s both trainable and isn’t the only thing that influences performance and impressive results (see Brad’s less than stellar VO2 measurement above).
Ride lots of miles, VO2max improves. Routinely engage in properly formulated and progressed HIIT intervals or sprint training, VO2max improves. Lose or gain weight, relative VO2max changes. Sit on the couch for a couple months, VO2max declines. Point being, it’s trainable.