Abstract des Autors

To examine the effects of endurance cycle training on urinary free cortisol (C) and serum testosterone (T), 27 male club-level cyclists (mean of the sample maximum oxygen consumption (XVO2max) = 3.95+/-0.30 L/min) progressively trained to an intensity of 85% VO2max for 60 min/session four times weekly for 7 weeks. Venous blood and a 24-h urine sample were collected each week and analyzed for hemoglobin (Hb), hematocrit (Hct), serum T, and urinary C. With training, VO2max was significantly increased to 4.42+/-0.30 L/min without significant changes from initial Hb (15.6 g/dl) or Hct (46%). Mean serum T levels were initially at the low end of the normal range (11.3+/-0.67 nM) and did not change significantly with training (10.0+/-0.88 nM). Urinary C levels were significantly greater than values in eight sedentary control subjects (74.8+/-10.4 nmol/day) and increased further with training from 111.4+/-8.6 to 210.5+/-15.9 nmol/day. The T/C ration was significantly decreased from 10.2(10**-2) to 4.8(10**-2) by the end of training. These results suggest that strenuous endurance cycle training alters the ratio of anabolic to catabolic hormones. With further investigation, urinary C may become a useful indicator of exercise training stress. Verf.-Referat