Beta-alanine (Carnosyn™) supplementation in elderly subjects (60-80 years): effects on muscle carnosine content and physical capacity

Abstract

The aim of this study was to investigate the effects of beta-alanine supplementation on exercise capacity and the muscle carnosine content in elderly subjects. Eighteen healthy elderly subjects (60-80 years, 10 female and 4 male) were randomly assigned to receive either beta-alanine (BA, n=12) or placebo (PL, n=6) for 12 weeks. The BA group received 3.2 g of beta-alanine per day (2×800 mg sustained-release Carnosyn™ tablets, given 2 times per day). The PL group received 2× (2×800 mg) of a matched placebo. At baseline (PRE) and after 12 weeks (POST-12) of supplementation, assessments were made of the muscle carnosine content, anaerobic exercise capacity, muscle function, quality of life, physical activity and food intake. A significant increase in the muscle carnosine content of the gastrocnemius muscle was shown in the BA group (+85.4%) when compared with the PL group (+7.2%) (p=0.004; ES: 1.21). The time-to-exhaustion in the constant-load submaximal test (i.e., TLIM) was significantly improved (p=0.05; ES: 1.71) in the BA group (+36.5%) versus the PL group (+8.6%). Similarly, time-to-exhaustion in the incremental test was also significantly increased (p=0.04; ES 1.03) following beta-alanine supplementation (+12.2%) when compared with placebo (+0.1%). Significant positive correlations were also shown between the relative change in the muscle carnosine content and the relative change in the time-to-exhaustion in the TLIM test (r=0.62; p=0.01) and in the incremental test (r=0.48; p=0.02). In summary, the current data indicate for the first time, that beta-alanine supplementation is effective in increasing the muscle carnosine content in healthy elderly subjects, with subsequent improvement in their exercise capacity.

Fig. 1

a Individual data for muscle carnosine content (arbitrary units) at baseline (PRE) and after 12 weeks of beta-alanine supplementation (POST-12). b Relative change (%) in muscle carnosine content (from PRE to POST-12). Asterisk indicates p < 0.05 when compared with the placebo group

Fig. 2

a Relative change (%) in total time of exercise during the TLIM test (TLIM) from baseline to 12 weeks of beta-alanine supplementation. b Relative change (%) in time to exhaustion during the incremental test (TTE). Asterisk indicates p < 0.05 when compared with the placebo group

Fig. 3

a Correlation between the relative change (%) in the time-to-exhaustion in the TLIM test and the relative change (%) in the muscle carnosine content. b Correlation between the relative change (%) in the time-to-exhaustion in the incremental test and the relative change (%) in the muscle carnosine content