Leptin and steroid hormone responses to exercise in adolescent female runners over a 7-week season

The purpose of the study was to investigate the responses of leptin and ste roid hormones to maximal exercise in adolescent female runners over a compe titive season. Seven adolescent female distance runners completed three tes ting trials during weeks 1, 4 and 7 of their high-school track season. Bloo d samples were collected before and after a discontinuous graded exercise t est to exhaustion (GXT) for each trial. Tests were administered during the subjects' normal training time (3:30 p.m.-5:00 p.m.). Compared to week 1, p eak O-2 uptake rose significantly during the season and was 10% and 7% high er at weeks 4 and 7, respectively. Levels of dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), cortisol, testosterone, and leptin increased significantly in response to the graded exercise tests. Testoste rone levels were also changed over the course of the study. Resting testost erone levels and testosterone responses to exercise in weeks 4 and 7 were b oth higher than in week 1. Resting concentrations and acute increases of th e other hormones were not changed over the season. It appears, therefore. t hat DHEA, DHEAS, cortisol, testosterone and leptin concentrations increase in response to running in adolescent female runners. Data also suggest that training and/or maturation increases resting testosterone concentrations a nd testosterone responses to running in adolescent female runners during a training season.