Examination of the relationship between HPA and heartrate variation in individual and team sports

Aim: This study aimed to investigate the relationship between heart rate variability (HRV) and hypothalamic-pituitary-adrenal (HPA) axis activity in adolescent male individual and team sport athletes and to determine the differences between the groups. Materials and Methods: The study included basketball, judo, athletics, football, and baseball athletes (n=25) aged 13-16 and sedentary healthy male volunteers (n=15). The Yoyo test was used as an aerobic capacity test, and saliva samples and electrocardiogram (ECG) recordings were taken from all participants before and after the test. HRV recordings were performed using the TLC 5000 holter. The t-test was used to analyze differences between groups, and Pearson correlation was used to examine the relationships between parameters. The level of significance was set at p<0.05. Results: The findings showed that there was a statistically significant difference in cortisol levels before the Yoyo test between individual and team sport athletes (p<0.05). In individual athletes, Min. R-R and AVRR were related to MaxVO2 before the test, while in team athletes, Max. R-R, AVRR, SDNN, RMSSD, VLF, LF, HF were related to MaxVO2 after the test, and in sedentary individuals, RMSSD and HF were related to MaxVO2 after the test (p<0.05). No statistically significant correlation was found between cortisol levels and HRV values in any group before or after the test (p>0.05). Conclusions: In conclusion, this study found that there was no difference in cortisol and HRV responses to an aerobic capacity test between individual/team sport athletes and sedentary individuals in adolescent males. HRV parameters were found to be related to MaxVO2 in all groups. HRV parameters can be recommended as a practical method for use in athlete selection and performance evaluation as a non-invasive application. Keywords: Cortisol, Heart rate variability, Exercise