Effects of resistance exercise volume and nutritional supplementation on anabolic and catabolic hormones

Seven resistance-trained men performed six bouts of resistance exercise, each separated by at least 1 week, in a crossover design. High, moderate and low volumes of exercise were used, each performed twice and followed immediately post-exercise by either a placebo or carbohydrate-protein supplementation. All bouts of resistance exercise were performed using a load equal to 100% of each subject's ten-repetition maximum (10-RM), and all rest periods between sets of exercise were 1 min. Blood was obtained before and at intervals after exercise until 120 min post-exercise. Lactate levels were significantly (P<0.05) elevated immediately post-exercise, and to a significantly greater extent after the greatest volume of exercise. Levels of growth hormone rose significantly after the greatest volume of exercise only. Those of insulin and glucose rose significantly after supplementation only. Cortisol levels tended to be higher after the greatest volume of exercise, but the differences were not significant. Supplementation had no effect on the lactate, growth hormone or cortisol responses to resistance exercise. The data indicate that volume of exercise and protein-carbohydrate supplementation can alter the metabolic and hormonal responses to resistance exercise independently. However, cortisol levels remain high after a high volume of resistance exercise, irrespective of whether a post-exercise carbohydrate-protein supplement is used.