Maximal Oxygen Uptake Adjusted for Skeletal Muscle Mass in Competitive Speed-Power and Endurance Male Athletes: Changes in a One-Year Training Cycle

We compared the changes in maximum oxygen uptake ([Formula: see text] max) calculated per skeletal muscle mass (SMM) with conventional [Formula: see text] max measures in a 1-year training cycle. We hypothesized that the pattern of changes would differ between SMM-adjusted and absolute or weight-adjusted values, and the differences between groups of distinct training specialization and status will depend on the measure used. Twelve sprinters (24.7 ± 3.3 years), 10 endurance runners (25.3 ± 5.3 years), and 10 recreationally trained controls (29 ± 4.5 years) performed a treadmill test until exhaustion to determine [Formula: see text] max. Their SMM was estimated based on the dual X-ray absorptiometry method and a regression equation. The significance of differences was assessed using analysis of variance (p ≤ 0.05). The pattern of the longitudinal change was not different between [Formula: see text] max/SMM and standard measures. Also, the significance of differences between sprinters and endurance athletes remained similar regardless of the [Formula: see text] max measure. Sprinters and controls had similar absolute (~4.3 L·min(−1)) and total weight-adjusted (~52 vs. ~56 mL·min(−1)·kg) [Formula: see text] max, but they significantly differed in SMM-adjusted [Formula: see text] max (~110 vs. ~130 mL·min(−1)·kg SMM(−1)). In summary, SMM-adjusted [Formula: see text] max is not more useful than standard measures to track longitudinal changes in competitive athletes. However, it allows to better distinguish between groups or individuals differing in training status. The results of our study are limited to male athletes.