First, I really enjoyed the piece on Tinman. Great insight.
I have an issue with this paragraph though.
Copied from the piece:
Schwartzâ€™s key postulation centers around Type IIa fibers. Type IIa fibers produce energy and sustained power â€” say the kind a runner would need during the final 400 meters of a mile â€” but because they rely on oxygen, not glucose, to produce energy, they are more resistant to fatigue. Furthermore, Schwartz discovered that, through training, Type IIb fibers can be converted to Type IIa fibers, allowing an athlete to fight off fatigue even longer.
Type IIa fibers are more oxidative than their IIb cousins, but oxygen does not supply energy (ATP). Glucose or glycogen provide ATP. These muscles use oxygen to create more ATP, but oxygen itself does not provide ATP.