Abstract des Autors

Chronic endurance exercise might induce suppression of HHGA in athletes. The effects of intensity of endurance exercise (EX) on HHGA in older athletes under adrenal suppression with dexamethasone (DEX) are not known. Therefore, we investigated HHGA in older athletes (age: 62.5 yrs) under 6 different conditions: A: without EX after DEX (orally, 22 p.m. the day before, 1.5 mg); B: without EX without DEX; C: during and after 5 hrs of low intensity bicycle ergometer-EX (55% VO2max) without DEX; D: 24 hrs after C and DEX at 22 p.m.: E: during and after 5 hrs of high intensity bicycle ergometer-EX (75% VO2max) without DEX; F: 24 hrs after E and DEX at 22 p.m. EX had no effect on serum concentrations of LH, FSH or testosterone (T). DEX had no effect on GnRH-induced increase of LH, FSH and T, induced, however, a reduction of T before GnRH. Neither low nor high intensity EX had any effect on LH, FSH or T after GnRH. Compared to young athletes, serum LH and FSH concentrations were elevated, T was not age-dependent. in contrast to young athletes, T-increase after EX was unaffected, which indicates a higher stability of the peripheral part of HHGA in older compared to younger athletes. Verf.-Referat