Oral creatine supplementation and upper extremity anaerobic response in females

The purpose of this study was to investigate the influence of creatine monohydrate (CrH2O) on upper extremity anaerobic response in strength-trained females involved in overhand sports. Two movements were utilized in this evaluation: elbow flexion (EF) and shoulder internal rotation (IR). Subjects were pair-matched and assigned to receive placebo (n = 13) or 25 g CrH2O (n = 11) for 7 days. Pre- and post-treatment measurements included peak concentric and eccentric isokinetic torque, isotonic 1RM, and fatigue (FAT) during EF; isotonic 1RM, FAT, and peak velocity during IR; and body weight. MANOVAs revealed significant interaction between treatment and trial for EF (p < .05) but not for IR or weight. Univariate analysis indicated a significantly greater change in EFFAT following CrH2O than following placebo. Thus, CrH2O did not influence peak EF or IR strength, IR work to fatigue, or IR velocity, but was associated with greater work capacity during fatiguing EF. These data suggest that CrH2O may enhance upper extremity work capacity, but this enhancement may not extend to the muscles primarily responsible for overhand sports performance.