Sex-Specific Accumulated Oxygen Deficit During Short- and Middle-Distance Swimming Performance in Competitive Youth Athletes

Introduction Since sex-specific accumulated oxygen deficit (AOD) during high-intensity swimming remains unstudied, this study aimed to assess AOD during 50, 100, and 200 m front-crawl performances to compare the responses between sexes and analyse the effect of lean body mass (LBM). Methods Twenty swimmers (16.2 ± 2.8 years, 61.6 ± 7.8 kg, and 48.8 ± 11.2 kg LBM—50% males) performed 50, 100, and 200 m to determine accumulated oxygen uptake (V̇O 2Ac ). The swimmers also performed an incremental test from which five submaximal steps were selected to estimate the oxygen demand (V̇O 2demand ) from the V̇O 2 versus velocity adjustment. V̇O 2 was sampled using a gas analyser coupled with a respiratory snorkel. AOD was the difference between V̇O 2demand and V̇O 2Ac , and LBM (i.e. lean mass not including bone mineral content) was assessed by dual-energy X-ray absorptiometry (DXA). Results A two-way ANOVA evidenced an AOD increase with distance for both sexes: 19.7 ± 2.5 versus 24.9 ± 5.5, 29.8 ± 8.0 versus 36.5 ± 5.8, and 41.5 ± 9.4 versus 5.2 ± 11.9 ml × kg −1 , respectively, for 50, 100, and 200 m (with highest values for females, P