Acute creatine supplementation in older men.
The hypothesis of this study was that short term creatine (Cr) ingestion in older individuals would increase body mass and exercise performance, as has been shown in younger subjects. Seventeen males 60-78 years old were randomly placed into two groups, Cr and placebo (P), and supplemented in double-blind fashion for 5 days. Subjects ingested either 5 g of Cr plus 1 g of sucrose 4x per day or 6 g of a sucrose placebo 4x per day. Isometric strength of the elbow flexors was assessed using a modified preacher bench attached to a strain gauge. Isokinetic exercise performance was assessed using an intermittent fatigue test of the knee extensors. Subjects performed 3 sets of 30 repetitions with 60 sec rest between sets. There was a small (0.5 kg) but statistically significant increase in body mass (p < 0.05) in the Cr group after supplementation. There was a significant overall interaction between groups in isokinetic performance from pre to post supplementation (group x time x set, p < 0.05). However, analysis of the groups separately revealed that the subjects in the Cr group demonstrated a small non-significant increase in isokinetic performance while subjects in the P group demonstrated a small non-significant performance decrement. There was no significant difference in isometric strength between groups from pre to post supplementation. These data suggest that acute oral Cr supplementation does not increase isometric strength and only produces small increases in isokinetic performance and body mass in men over the age of 60.
Rawson
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ES
Department of Exercise Science, University of Massachusetts, Amherst 01003, USA. erawson@excsci.umass.edu
Clarkson
P M
PM
D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition; D003401:Creatine / Q000494:pharmacology*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D014891:Weight Lifting
D003401:Creatine