@article{ajssm2021914,
author={{Bailey, Janel and Irving, Rachel and Dawson, Paula and Brown, Dialo-Rudolph and Campbell, Eon},
title={Influence of Training-induced Testosterone and Cortisol Changes on Skeletal Muscle and Performance in Elite Junior Athletes},
journal={American Journal of Sports Science and Medicine},
volume={9},
number={1},
pages={13--23},
year={2021},
url={http://pubs.sciepub.com/ajssm/9/1/4},
issn={2333-4606},
abstract={This study aimed to investigate the influence of testosterone (T) and cortisol (C) on Skeletal Muscle Markers (SMM) at each phase of a track and field macrocycle. On a secondary basis, we also sought to determine whether C or T moderates the relationship between SMM and performance. Twenty-eighth (28) elite junior sprint athletes (15.48 ¡À1.89 years), and 13 non-athletic (16.15 ¡À1.51 years), age and gender-matched controls participated in this study. Isometric muscle strength (MS) and muscle thickness (MTH) were considered SMM. Salivary C and T levels, MS and MTH were collected between 2:30 and 3:00 p.m. before training sessions, twice during the preparatory phase [baseline (T1) and midway into the specific preparation period (T2)] and twice in competition phase [midway point of pre-competition (T3) and midway of the major competition period (T4)]. Performance data were collected during the competition phase only. No significant improvements in SMM were observed. T and T/C ratio significantly increased (p<0.05) across the season, while C levels increased relative to baseline only. While T levels did not significantly predict SMM at any phase, C levels significantly explained (p<0.05) a 60% and 74% variance in MTH and performance respectively. However, neither C nor T significantly moderated the relationship between SMM and performance. These findings suggest that raising T levels across a season may be more indicative of a response to training load, rather than a reflection of skeletal muscle adaptation. While training-induced C, which was demonstrated to have a greater influence on SMM is more sensitive to muscle function changes and performance compared to testosterone.},
doi={10.12691/ajssm-9-1-4}
publisher={Science and Education Publishing}
}