Prolactinemia in exercising male athletes

8 male collegial athletes were submitted at random to three (55, 70 and 85% of VO2 max) ergocycle exercises of 20-min duration. Venous blood samples were obtained before, during and after ergocycling sessions by antecubital catheterization. Serum prolactin was measured by RIA using specific antiserum. The exercise treatments induced a blood prolactin response proportional to the intensity of the work loads.