AUTHOR=Theos Apostolos , Bogdanis Gregory C. , Jansson Daniel , Nevill Alan M. , Papaspyrou Aggeliki , Maridaki Maria 

TITLE=Oxygen Uptake in Repeated Cycling Sprints Against Different Loads Is Comparable Between Men and Preadolescent Boys

JOURNAL=Frontiers in Physiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.814056

DOI=10.3389/fphys.2022.814056

ISSN=1664-042X

ABSTRACT=<p>Children recover faster than adults in repeated sprints, but it is unclear if their aerobic responses differ.</p><sec><title>Purpose</title><p>This study tested the hypothesis that aerobic response (VO<sub>2</sub>) during repeated sprints is greater in preadolescent boys than in men. Further, this study compared normalization with conventional ratio-scaling and scaling with the use of body mass (BM) as a covariate.</p></sec><sec><title>Methods</title><p>Nine boys (age: 11.8 ± 0.6 years, swimmers) and 11 men (age: 21.7 ± 0.6 years, recreational athletes) performed 10 maximal 6-s cycling sprints separated by 24-s of passive recovery, against two loads (optimum and 50% of optimum). Oxygen uptake (VO<sub>2</sub>) was measured continuously.</p></sec><sec><title>Results</title><p>Men’s mean power output (MPO) was greater than boys in each sprint, both in absolute (unscaled) values ( <italic>p</italic> &lt; 0.05) and when adjusted for lean leg volume ( <italic>p</italic> &lt; 0.05). Children had lower absolute VO<sub>2</sub> ( <italic>p</italic> &lt; 0.05) than men, but when it was adjusted for BM or power-output, VO<sub>2</sub> was comparable between men and boys. Thus, most of the difference in VO<sub>2</sub> between men and boys was due to body size and power-output differences.</p></sec><sec><title>Conclusion</title><p>Our results suggest that men and boys have similar VO<sub>2</sub> during repeated sprints when appropriately adjusted to body mass or power output. Results highlight the importance of using appropriate scaling methods to compare adults’ and children’s aerobic responses to high-intensity exercise.</p></sec>