Creatine Loading Favors Male Runners

NORMAN, Okla.Short-term, high-dosage creatine supplementation may improve anaerobic running capacity in men, but not women, according to recent research from the University of Oklahoma published online ahead of print in the Journal of Strength and Conditioning Research. Acknowledging creatine loading has been linked to increased body weight and may impact weight-bearing exercise, the researchers studied 50 moderately trained male and female volunteers in randomized, double-blinded, placebo (PL)-controlled, repeated-measures design. They used the critical velocity test, which provide variable anaerobic running capacity (an estimate of anaerobic energy reserves in the muscles), to quantify the relationship between total running distance and time to exhaustion.

A three-day testing procedure was conducted, including maximal oxygen consumption test (o2max) on day one while on treadmill. Days tow and three featured treadmill running at varying percentages of Vmax.

As for supplementation, subjects were randomly assigned to receive 4 packets per day of either creatine (1 packet = 5 g creatine citrate, 18 g dextrose) or placebo (1 packet = 18 g dextrose) for five consecutive days. Results showed men on creatine loading had 23-percent higher anaerobic running capacity (ARC), while bodyweight increases were non-significant. There was not a significant increase in ARC in women taking creatine preload.