β-Alanine ingestion increases muscle carnosine content and combat specific performance in soldiers

Abstract

The purpose of this study was to examine the effect of β-alanine (BA) ingestion on tissue carnosine levels and the impact such changes would have on combat specific activity. Eighteen soldiers (19.9 ± 0.8 year) from an elite combat unit were randomly assigned to either a 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 2.5 km 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. 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 2.5 km 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. In summary, 30-days of BA ingestion can increase muscle carnosine content and improve aspects of military specific performance. Although cognitive performance was significantly greater in participants consuming BA 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.

Effects of β-alanine supplementation on physical performance, cognition, endocrine function, and inflammation during a 24 h simulated military operation

“…These results were not consistent with recent animal studies suggesting that when BA ingestion occurs prior to stressful stimuli, elevations in brain carnosine content is associated with an increased resiliency to various stressors by reducing the inflammatory response (Hoffman et al. , ). Whether elevations in muscle carnosine content has similar anti‐inflammatory or muscle protective properties is not well‐understood.…”

“…A subsequent study using the same dosing protocol (6.0 g/day for 4‐weeks) resulted in a significantly faster time for a 50 m casualty carry in soldiers supplementing with BA compared to soldiers consuming the PLA (Hoffman et al. ). This present investigation appears to be the first study to examine the effects of BA supplementation during a 24 h SUSOP consisting of sleep deprivation, caloric restriction, and physical exertion.…”

“…These elevations also appear to increase the expression of BDNF (Murakami and Furuse ; Hoffman et al. , ), which may promote synaptic plasticity and neurogenesis (Wetmore et al. ; Figurov et al.…”

“…), potentially reducing neurodegeneration associated with the inflammatory response to stress, leading to improved cognitive function and mood states (Thomas and Russo ; Murakami and Furuse ; Hoffman et al. , ). BA supplementation has been previously demonstrated to increase brain carnosine concentrations in murine models (Murakami and Furuse ; Hoffman et al.…”

“…Elevations in brain carnosine also appear to increase the expression of brain‐derived neurotropic factor (BDNF) in the hippocampus and cerebral cortex (Murakami and Furuse ; Hoffman et al. , ). BDNF plays a key role in brain health by promoting synaptic plasticity and neurogenesis (Wetmore et al.…”