The influence of 8 weeks of whey-protein and leucine supplementation on physical and cognitive performance.
The purpose of this study was to investigate the ability of whey-protein and leucine supplementation to enhance physical and cognitive performance and body composition. Thirty moderately fit participants completed a modified Air Force fitness test, a computer-based cognition test, and a dual-energy X-ray-absorptiometry scan for body composition before and after supplementing their daily diet for 8 wk with either 19.7 g of whey protein and 6.2 g leucine (WPL) or a calorie-equivalent placebo (P). Bench-press performance increased significantly from Week 1 to Week 8 in the WPL group, whereas the increase in the P group was not significant. Push-up performance increased significantly for WPL, and P showed a nonsignificant increase. Total mass, fat-free mass, and lean body mass all increased significantly in the WPL group but showed no change in the P group. No differences were observed within or between groups for crunches, chin-ups, 3-mile-run time, or cognition. The authors conclude that supplementing with whey protein and leucine may provide an advantage to people whose performance benefits from increased upper body strength and/or lean body mass.
Air Force Research Laboratory, Brooks Air Force Base, San Antonio, TX, USA.
Thomas B
TB
Walker
Jessica
J
Smith
Monica
M
Herrera
Breck
B
Lebegue
Andrea
A
Pinchak
Joseph
J
Fischer
D015502:Absorptiometry, Photon; D000222:Adaptation, Physiological / Q000187:drug effects / Q000502:physiology; D000328:Adult; D000704:Analysis of Variance; D001823:Body Composition / Q000187:drug effects / Q000502:physiology; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D004044:Dietary Proteins / Q000378:metabolism / Q000494:pharmacology; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007930:Leucine / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008889:Military Personnel; D008894:Milk Proteins / Q000378:metabolism / Q000494:pharmacology*; D053580:Muscle Strength / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000254:growth & development; D000067816:Whey Proteins
D004044:Dietary Proteins; D008894:Milk Proteins; D000067816:Whey Proteins; D007930:Leucine