This investigation compared concentrations of circulating serum testosterone before during, and after a submaximal treadmill run (30 min at 800% [latin capital V with dot above]O2 max) with samples obtained on a baseline (nonexercise) day. Baseline testosterone concentrations were obtained from 6 men (mean age 24 yrs) via an indwelling catheter in the medial cubital vein. An initial sample of blood was followed 10 min later by 10 subsequent samples each taken at 10-min intervals. Blood samples were obtained at similar times and intervals on the day of the treadmill run. There was a significant (p gt; 0.05) increase in serum testosterone concentration immediately after the treadmill run when compared to baseline concentrations. No other significant differences were found between baseline and postexercise samples up to 60 min. These results indicate that submaximal treadmill running caused an increase in circulating serum testosterone immediately postexercise that was greater than baseline levels.
(C) 1996 National Strength and Conditioning Association