Hormone Response to Jumping Tests in Adolescent Sprinters

The aim of this study was to investigate the effects of three different duration (1, 3 or 5 min) rest intervals on hormonal response in 10x10 hurdle jumping series. Eleven adolescent male sprinters and jumpers (16.2±0.9 years, height 170.5±7.9 cm, body mass 70.9±11.1 kg, body mass index 22.0±3.4 kg/m2) participated in the study. An exercise session consisted of 10 two-legged jumps with arm swing over ten 76 cm high hurdles in 10 series which were separated by either 1-, 3or 5-minute rest intervals. Venous blood samples were obtained before and after the session and cortisol (CORT), testosterone (TEST) and the growth hormone (GH) concentrations were analyzed. Mean jumping times over 10 hurdles using one (7.67±0.92 sec), three (7.44±0.66 sec) or five (7.14±0.54 sec) minutes of recovery were not significantly different from each other (p>.05). No significant changes were noted in CORT and TEST concentrations as a result of different exercise sessions. Compared with the initial value, GH increased rapidly (p<.001) after the jumping test with a 1-min rest interval. A negative correlation (r=-.791) was found between mean jumping time using 5-min rest intervals and changes in the TEST concentration. This study indicates that short jumping series with different length rest intervals do not significantly change TEST or CORT concentrations. However, the shortest rest interval (one minute) causes significant changes in GH concentration in adolescent sprinters and jumpers.