LONG-TERM CREATINE INTAKE IS BENEFICIAL TO MUSCLE PERFORMANCE DURING RESISTANCE TRAINING

The effects of oral creatine supplementation on muscle phosphocreatine (PCr) concentration, muscle strength, and body composition were inves tigated in young female volunteers (n = 19) during 10 wk of resistance training (3 h/wk). Compared with placebo, 4 days of high-dose creatin e intake (20 g/day) increased (P < 0.05) muscle PCr concentration by 6 %. Thereafter, this increase was maintained during 10 wk of training a ssociated with low-dose creatine intake (5 g/day). Compared with place bo, maximal strength of the muscle groups trained, maximal intermitten t exercise capacity of the arm flexors, and fat-free mass were increas ed 20-25, 10-25, and 60% more (P < 0.05), respectively, during creatin e supplementation. Muscle PCr and strength, intermittent exercise capa city, and fat-free mass subsequently remained at a higher level in the creatine group than in the placebo group during 10 wk of detraining w hile low-dose creatine was continued. Finally, on cessation of creatin e intake, muscle PCr in the creatine group returned to normal within 4 wk. It is concluded that long-term creatine supplementation enhances the progress of muscle strength during resistance training in sedentar y females.