Volek, J. S., Duncan, N. D., Mazzetti, S. A., Mutukian, M., Gomez, A L., Staron, R. S., & Kraemer, W. J. (1999). Performance and muscle fiber adaptations to 12 weeks of creatine supplementation and heavy resistance training. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 362.

The effects of resistance training and creatine supplementation on physiological adaptations were observed in resistance-trained males (N = 19) over 12 weeks. Ss were matched into a creatine (N = 10) or placebo (N = 9) group. Heavy training was performed 3-4 times per week. For the first week, 25 g of creatine or placebo was consumed. For the remainder of the study, 5 g of supplement or placebo was ingested.

Body mass, fat-free mass, maximal squat and bench press strength, and total muscle fiber cross-sectional area were significantly elevated in both groups. Fat-free mass and bench-press strength were significantly greater in creatine Ss. Creatine Ss also increased delta changes in type I, IIA and IIAB fibers, and in the volume lifted in bench press during weeks 5-8 (which could account for the increased strength in bench press in the creatine group).

Implication. Creatine supplementation increases muscle mass, performance, and muscle fiber hypertrophy presumably because of the high quality of training it supports.

Return to Table of Contents for this issue.