CREATINE LOADING DOES NOT INCREASE PCr RESYNTHESIS IN INTERMITTENT EXERCISE
Vandenberghe, K., Van Hecke, P., Van Leemputte, M., Vanstapel, F., & Hespel, P. (1999). Phosphocreatine resynthesis is not affected by creatine loading. Medicine and Science in Sports and Exercise, 31, 236-242.
The effect of creatine loading on muscle PCr (creatine phosphate) breakdown and resynthesis and muscle performance during high intensity intermittent muscle contractions was investigated. It was hypothesized that this might contribute to creatine's effect on exercise of this type. Creatine (25 gm/day) or a placebo was ingested for five days, each experience being five weeks apart. Ss (N = 9) performed knee extensions after days 2 and 5 in each condition.
Creatine caused resting muscle PCr to increase 11% after two days and 16% after five days. Torque production was also increased. PCr breakdown and resynthesis was similar for both conditions.
Implication. Creatine loading does not facilitate muscle PCr resynthesis during intermittent isometric muscle contractions when its performance effects are evident.