Muscle Strength Recovery Following Acute Bout of Resistance Training: Role of Dehydroepiandrosterone Sulfate

Abstract

The purpose of this study was to investigate the effects of acute bout of moderate intensity resistance exercise on the recovery of maximal isometric muscle strength. Additionally, the association between muscle strength recovery and serum level of dehydroepiandrosterone sulfate (DHEA-S) was examined. Eighteen male hockey players were assigned into either high muscle strength (120.33±7.65 kg/w, HMS, n=9) or low muscle strength (71.66±3.57 kg/w, LMS, n=9) based on their maximal isometric strength of lower extremities. All subjects performed an acute bout of resistance training, consisting of 6 exercises. Three sets of 8 repetitions with 50% 1-RM intensity were performed for all exercises. Fasting blood samples were collected at pre-exercise, immediately after exercise, 48h and 72h after exercise for determining the serum DHEA-S and cortisol levels. Maximal isometric strength of upper and lower extremities was measured at 48h and 72h after acute bout of resistance exercise. No significant differences were detected in anthropometric measures between two groups. The serum DHEA-S level was significantly lower in HMS group at immediately and 48h after acute resistance exercise. However, there were no differences in serum cortisol levels at each time point between two groups. Maximal isometric muscle strength recovery was significantly faster in HMS group compared to LMS group. In addition, serum DHEA-S and muscle strength recovery showed markedly negative correlation. In conclusion, HMS group showed better recovery rate of muscle strength after acute bout of resistance exercise. This faster recovery could be associated with endogenous DHEA-S level, suggesting that endogenous DHEA-S might account for individual differences in training adaptation in response to resistance exercise.