Effects of pre- and post-exercise intake of performance supplements on body composition, circumferences, and muscle strength in trained men during 6 weeks of resistance training

Background Resistance training (RT) enhances muscle protein synthesis and increases muscle strength and hypertrophy. Protein and amino acid supplements have been shown to augment the physiological improvements associated with RT such as improved body composition, muscular strength, and hypertrophy while suppressing exerciseinduced proteolysis. Supplements that also contain creatine and caffeine have been shown to improve lean mass and muscular strength in moderately-trained recreational athletes. Recently, consumption of a supplement before RT that contains protein, caffeine, and creatine has been shown to increase fat-free mass (FFM) and upper-body strength in sedentary, untrained males. Therefore, the purpose of this study was to investigate the impact of preand post-workout performance supplementson body composition, circumferences, and maximal strength in resistance trained men.