[Blood testosterone levels before and after races of various duration].

The blood testosterone levels have been measured in nine middle-distance runners seven walkers and in eighteen marathon runners before and after races of different duration. Most of the athletes (24 out of 34, 70,6% of the population) have shown an increase in testosterone levels soon after physical exercise. The values varied from an average of 5,83 to 7,72 ng/ml in middle distance runners, from 4,70 to 6,70 ng/ml in walkers, and from 5,00 to 6,82 ng/ml in marathon runners. The Authors hypothesize that prolonged physical activity in well-trained athletes may determine an augmented incretion of testosterone.