Effect of Creatine and Protein Supplementation Combined With Resistance Training on Muscle Mass and Strength in Older Men

Muscle loss with age has a negative effect on strength and power. Factors contributing to the age-related loss of muscle include physical inactivity and undernutrition. The purpose of this thesis was to determine how to maximize muscle accretion and strength through the combination of nutritional supplementation and resistance training in older men, and to determine whether these interventions could eliminate deficits in muscle mass and strength compared to young men. This purpose was achieved by: (a) determining differences in muscle mass, strength, and power in upper and lower body muscle groups between young and older men; (b) investigating the effects of protein supplementation before and after resistance training sessions in older men; and (c) investigating the effects of creatine combined with protein supplementation in older men. The first study showed that muscle mass, strength, and power for the knee flexors and extensors and ankle plantar flexors were reduced more with age than measures for the elbow flexors and extensors. These results were used to determine whether nutritional supplementation and resistance training in older men could eliminate deficits in muscle mass and strength compared to young men. The second study determined the effects of protein supplementation immediately before and after training sessions for 12 weeks in older men ages 59–76 years, and whether this intervention could eliminate deficits in muscle mass and strength compared to young men from the first study. Results showed that the timing of protein supplementation, either before or after resistance training, had no effect on lean tissue mass, muscle thickness, or strength. At the end of the study the older group still had lower lean tissue mass, lower muscle thickness of the knee extensors and flexors and ankle plantar flexors, and lower bench press strength compared to young men, suggesting that a longer intervention in required. The third study determined the effects of creatine and protein supplementation during 10 weeks of resistance training in older men. In addition, these results, combined with the results of 17 subjects from the second study, determined whether PhD ABSTRACT