Androgen receptor content following heavy resistance exercise in men

The purpose of the present investigation was to examine androgen receptor (AR) content in the vastus lateralis following two resistance exercise protocols of different volume. Nine resistance-trained men (age = 24.3 +/- 4.4 years) performed the squat exercise for 1 (SS) and 6 sets (MS) of 10 repetitions in a random, counter-balanced order. Muscle biopsies were performed at baseline, and 1 h following each protocol. Blood was collected prior to, immediately following (IP), and every 15 min after each protocol for I h. No acute elevations in serum total testosterone were observed following SS, whereas significant 16-23% elevations were observed at IP, 15, and 30 min post-exercise following MS. No acute elevations in plasma cortisol were observed following SS, whereas significant 31-49% elevations were observed for MS at IP, 15, and 30 min post-exercise. Androgen receptor content did not change I h following SS but significantly decreased by 46% following MS. These results demonstrated that a higher volume of resistance exercise resulted in down-regulation of AR content I h post-exercise. This may have been due to greater protein catabolism associated with the higher level of stress following higher-volume resistance exercise. (c) 2004 Published by Elsevier Ltd.