ACUTE EFFECTS OF DIFFERENT INTENSITIES OF WEIGHT-LIFTING ON SERUM TESTOSTERONE

The purpose of this investigation was to determine the effect of moder ate weight lifting (MWL) and light weight lifting (LWL) on concentrati ons of serum testosterone in males. Baseline testosterone concentratio ns were determined via an indwelling catheter in the median cubital ve in. An initial sample of blood was followed 7 min later by five sample s taken at 4-min intervals. A final sample was taken 10 min after the last 4-min blood draw. Blood samples were obtained at similar times an d intervals on the weight lifting days. The MWL consisted of four sets of six squats at 90-95% of a six-repetition maximum (RM), while the L WL consisted of four sets of 9 or 10 repetitions at 60-65% of the weig ht used for the sets during MWL. There was a significant increase in s erum testosterone concentrations following the fourth set for both MWL and LWL when compared with baseline concentrations and both MWL and L WL testosterone concentrations returned to baseline levels at 10 min p ostexercise. These results indicate that MWL and LWL caused increases in serum testosterone that were greater than those associated with bas eline levels. Postexercise responses for the MWL and LWL were similar.