Research
Mixed
The maximum rate of oxygen consumption (VO2max) per unit volume is inversely proportional to muscle fiber cross-sectional area (CSA) due to oxygen diffusion constraints, creating an evolutionary design constraint where larger fibers cannot support high oxidative capacity without developing anoxic cores.
As muscles get larger, their ability to use oxygen efficiently per unit of volume decreases. This is why bodybuilders often have lower VO2max relative to their muscle mass compared to endurance athletes. You cannot simply 'train' away this physical diffusion limit, though capillary density can help mitigate it.
GoodSupportsHIGH confidence
Muscle fibers with a high oxidative capacity are relatively small compared to fibers with a low oxidative capacity... The relationship between cross-sectional area and mitochondrial density implies that a muscle fiber can hypertrophy (and become stronger) at the expense of its maximum steady state power per fiber volume (i.e., endurance capacity).
Why this rating
Review of biophysical models and experimental data.
Source
The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?
T. van Wessel et al. · European Journal of Applied Physiology · 2010
DOI 10.1007/s00421-010-1545-0
narrative_reviewCited 286×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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