β-Alanine Ingestion Increases Muscle Carnosine Content and Combat Specific Performance in Tactical Athletes: 2197 Board #1 May 29, 9

PURPOSE: To examine the effect of β-alanine ingestion on tissue carnosine levels and the impact such changes would have on combat specific activity. METHODS: Eighteen soldiers (19.9±0.8y) from an elite combat unit were randomly assigned to either a β-alanine (BA) or placebo (PL) group. Before and following a 30-day supplementation period carnosine content of the gastrocnemius muscle and brain was determined by proton magnetic resonance spectroscopy. During each testing session participants performed military relevant tasks that included a 2.5km run, a 1-min sprint, 50-m casualty carry, repeated 30-m sprints with target shooting, and a 2-min serial subtraction test (SST) to assess cognitive function under stressful conditions. RESULTS: A significant elevation (p=0.048) in muscle carnosine content was noted in BA compared to PL. Changes in muscle carnosine content was correlated to changes in fatigue rate (r=0.633, p=0.06). No changes (p=0.607) were observed in brain carnosine content. Following supplementation, no differences were noted in 2.5km run, 1-min sprint, repeated sprint, or marksmanship performance, but participants in BA significantly (p=0.044) improved their time for the 50-m casualty carry and increased their performance (p=0.022) in the SST compared to PL. CONCLUSIONS: 30-days of β-alanine ingestion can increase muscle carnosine content and improve aspects of military specific performance. Although cognitive performance was significantly greater in participants consuming β-alanine compared to placebo, current study methods were unable to detect any change in brain carnosine levels, thus the precise mechanism underlying these effects remains elusive.