Effect of post-exercise supplement consumption on adaptations to resistance training

• Published in: Journal of the American College of Nutrition 2004-08, Vol.23 (4), p.322-330
• Main Authors: Rankin, J.W, Goldman, L.P, Puglisi, M.J, Nickols-Richardson, S.M, Earthman, C.P, Gwazdauskas, F.C
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Adolescent; Adult; Animals; athletes; Basal Metabolism - physiology; Beverages; Biological and medical sciences; body composition; Body Composition - physiology; dietary carbohydrate; Dietary Carbohydrates - administration & dosage; dietary protein; Dietary Supplements; ergogenic aids; exercise; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Humans; Hydrocortisone - blood; hypertrophy; Insulin-Like Growth Factor I - analysis; Male; Milk; Muscle, Skeletal - physiology; nutrition for strength athletes; sports nutrition; strength training; testosterone; Testosterone - blood; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Weight Lifting - physiology; weight training
• ISSN: 0731-5724; 1541-1087
• DOI: 10.1080/07315724.2004.10719375

Objective: Athletes are interested in nutritional manipulations that may enhance lean tissue gains stimulated by resistance training. Some research demonstrates that acute consumption of food containing protein causes superior muscle protein synthesis compared to isoenergetic foods without protein. This benefit has not been verified in longer-term training studies. We compared body composition and muscle function responses to resistance training in males who consumed a carbohydrate or a multi-macronutrient beverage following each training session. Methods: Nineteen, untrained men (18-25 years) consumed either a milk (MILK) or a carbohydrate-electrolyte (CHO) drink immediately following each workout during a 10 week resistance training program. Muscle strength (1RM for seven exercises), body composition (DXA scan), fasted, resting concentrations of serum total and free testosterone, cortisol, IGF-1, and resting energy expenditure (REE) were measured prior to and at the end of training. Results: Resistance training caused an increase (44 ± 4%, p < 0.001) in muscular strength for all subjects. The training program reduced percent body fat (8%, p < 0.05, -0.9 ± 0.5 kg) and increased fat-free soft tissue (FFST) mass (2%, 1.2 ± 0.3 kg, p < 0.01). MILK tended to increase body weight and FFST mass (p=0.10 and p=0.13, respectively) compared to CHO. Resting total and free testosterone concentrations decreased from baseline values in all subjects (16.7%, 11%, respectively, p < 0.05). Significant changes in fasting IGF-1, cortisol, and REE across training were not observed for either group. Conclusion: Post-resistance exercise consumption of MILK and CHO caused similar adaptations to resistance training. It is possible that a more prolonged training with supplementation period would expand the trend for greater FFST gains in MILK.