Hormonal And Heart Rate Changes To Maximal Exercise In Elite Adolescent Athletes

Abstract

One of the main biomarkers of stress is the steroid hormone cortisol (C), while testosterone (T) and estrogen (E) steroid hormones are associated with physical activity. PURPOSE: To determine the relationship between a maximal swimming exercise and hormone level changes and acute training’s influence on the stress level in elite adolescent athletes. METHODS: The study was conducted with 31 participants (boys: n=19, mean age±SD: 16.34±1.12 years; girls n=12, 15.17±0.81 years) from the field of water sports (swimming: n=10; water polo: n=21). The young elite athletes completed a maximal freestyle swimming test (200 meter) after a 25 minutes unified warm-up. Saliva samples were collected before (C1), immediately after the exercise (C2) and after a 30 minutes rest (C3). Free hormone levels in saliva were quantified by using IBL ELISA kits. Heart rate (HR) was measured throughout the whole procedure (Polar V800). We used the Brunel questionnaire to determine the participants’ mood states after the field test. RESULTS: There was significant rise in boys’ C levels compering to the C1 (0.176±0.134 μg/dl) with C2 (0.339±0.278 μg/dl; p=0.030) and C3 (0.426±0.319 μg/dl; p=0.001) measured results. Rise in girls’ C level was not significant (p=0.057), however their C2 (r=0.71) and C3 (r=0.60) levels correlated with their peak HR in swimming test. Boys’ T levels decreased significantly after the exercise (0.0046±0.0023 μg/dl) compared to basal levels (0.0061±0.0028 μg/dl) and T/C ratio also decreased (basal: 0.047±0.032 μg/dl; after exercise: (0.02±0.015 μg/dl). There was no significant difference in girls’ E levels, however their C3 levels correlated with their happiness (r=0.62), and C3−C1 concentration difference correlated also with happiness (r=0.68) and calmness (r=0.71) items of the Brunel scale. CONCLUSION: These results justify the application of the swimming field test to monitor maximal performance induced hormonal changes in adolescent athletes. Changes in T and T/C levels go against the experienced trend in literature therefore we feel the need of further analysis of our results. Moreover, the repeated measures might be an effective way to register the alarming symptoms of the common overtraining syndrome in swimming. Supported by the ministry of human capacities [ÚNKP-18-3-I-TE-6].