E. S. Rawson, M. L. Wehnert, and P. M. Clarkson, FACSM. University of Massachusetts, Amherst, MA. Supported by a grant from Pfanstiehl Laboratories, Inc. Supplement provided by The NutraSense Company.

The purpose of this investigation was to determine the effects of oral creatine supplementation on body composition, maximal strength of the elbow flexors, and fatigue of the knee extensors in males over the age of 60. Twenty males aged 60-82 years old were placed into two groups, creatine (Cr) and placebo (P), and supplemented in double blind fashion. Subjects ingested either 20 grams of Cr (5 grams of Cr plus 7 grams of dextrose 4 times per day for 10 days) or an identical looking and tasting dextrose placebo for the same duration. Following this loading phase, subjects ingested either 4 grams of creatine or the placebo once per day for 20 days. All tests were conducted pre and again following 10 and 30 days of supplementation. Body Composition was assessed using hydrostatic weighing. Maximal strength (MVC) of the elbow flexors was assessed using a modified preacher bench attached to a strain gauge. Leg fatigue was determined using a Biodex isokinetic dynamometer. Subjects performed 5 sets of 30 maximal voluntary contractions at 1800 per/second with 1 minute of recovery between sets. Leg fatigue was expressed as the total peak torque generated during the five sets of exercise. There was a significant difference over time in body mass (p<0.05). Although this difference was not statistically significant between groups, the mean increases in body mass were 0.78 ± 0.27 and 0.32 ± 0.28 kg for the Cr and P groups, respectively, possibly indicating a trend. There were no significant differences in MVC, body density, or fat free mass between groups from pre to post. There was a significant difference (p<0.05) between groups over time in leg fatigue following supplementation. The data suggest that 30 days of creatine supplementation may have a beneficial effect on reducing muscle fatigue in men over the age of 60.