Heavy resistance training and peri-exercise ingestion of a multi-ingredient ergogenic nutritional supplement in males: Effects on body composition,Muscle performance and markers of muscle protein synthesis

This study determined the effects of heavy resistance training and peri-exercise ergogenic multi-ingredient nutritional supple-ment ingestion on blood and skeletal markers of muscle protein synthesis (mps),body composition,and muscle performance. twenty-four college-age males were randomly assigned to either a multi-ingredient sizeon maximum performance (size) or protein/carbohydrate/creatine (pcc) comparator supplement group in a double-blind fashion. body composition and muscle performance were assessed,and venous blood samples and muscle biopsies were obtained before and after 6 weeks of resistance training and supplementation. data were analyzed by 2-way anova (p ≤ 0.05). total body mass,body water,and fat mass were not differentially affected (p > 0.05). however,fat-free mass was significantly increased in both groups in response to resistance training (p = 0.037). lower-body muscle strength (p = 0.029) and endurance (p = 0.027) were significantly increased with resistance training,but not supplementation (p > 0.05). serum insulin,igf-1,gh,and cortisol were not differ-entially affected (p > 0.05). muscle creatine content was significantly increased in both groups from supplementation (p = 0.044). total muscle protein (p = 0.038),mhc 1 (p = 0.041),mhc 2a,(p = 0.029),total irs- (p = 0.041),and total akt (p = 0.011) were increased from resistance training,but not supplementation. in response to heavy resistance training when com-pared to pcc,the peri-exercise ingestion of size did not preferentially improve body composition,muscle performance,and markers indicative of mps. © journal of sports science and medicine.