RESISTANCE EXERCISE VOLUME AFFECTS METABOLIC AND HORMONAL RESPONSES
Ratamess, N. A., Kraemer, W. J., Volek, J. S., Maresh, C. M., Van Heest, J. L., Rubin, M. R., French, D. N., Sharman, M. S., Vescovi, J. D., & Silvestre, R. (2004). Effects of heavy resistance exercise volume on post-exercise androgen receptor content in resistance-trained men. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 1659.
This study examined the acute hormonal response in the blood and androgen receptor content in the vastus lateralis muscle following two resistance exercise protocols consisting of different volumes. Men (N = 9) with resistance training experience performed a squat exercise for a single set and multiple set (six sets) of 10 repetitions with 80-85% of 1 RM in a random, counter-balanced order separated by one week. Muscle biopsies were performed at baseline (10 days before the first protocol), and one hour following each protocol. Blood was collected before, immediately following (IP), and every 15 minutes after each protocol for one hour.
Both protocols resulted in significant reductions in plasma volume and elevations in lactate immediately following exercise with the magnitude of increase significantly greater following the multiple set. For serum total testosterone, no acute elevations were observed following the single set whereas significant elevations were observed at IP (16%), 15 (23%), and 30 (18%) minutes post-exercise following the multiple set. For plasma cortisol, no differences were observed for the single set over time except for a reduction at 60 minutes post-exercise whereas significant elevations were observed for the multiple set at IP (31%), 15 (48%), and 30 (49%) minutes post-exercise. For the free androgen index (ratio of total testosterone to sex hormone-binding globulin), significant reductions were observed at IP and 45 minutes post-exercise following the single set whereas only trends for elevations were observed at 15 and 30 minutes post-exercise following the multiple set. Androgen receptor content did not change one hour following the single set but significantly decreased by 46% following the multiple set.
Increasing the volume of resistance exercise significantly affects acute metabolic and hormonal responses. In addition, the higher volume of resistance exercise resulted in a reduction in androgen receptor content in skeletal muscle one hour post-exercise possibly due to greater protein catabolism associated with the higher level of stress.
Implication. High volumes of resistance exercises affect metabolic and hormonal responses.
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