The accumulation of metabolites and other exercise waste products such as hydrogens (H+, which are produced together with lactate) is a limiting factor of performance, especially during high-intensity exercise (also known as ‘anaerobic’ exercise). This accumulation of H+ results in a decrement of the organism’s pH, increasing acidity and impairing muscle contraction. Our organism has several mechanisms called “physiological buffers” to avoid this diminution of pH, being one of the most important the bicarbonate buffer system.
Similarly, muscle carnosine also acts as a buffer against the diminution of intramuscular pH. Beta-alanine supplementation has proven to increase the levels of intramuscular carnosine. For instance, a study observed that the intake of 3.2 g/day of Beta-Alanine increased muscle carnosine around 50% above basal levels (Stegen et al. 2014). Moreover, when these subjects consumed 1.2 g/day of Beta-alanine during 6 weeks carnosine levels remained 30-50% higher than at baseline (Stegen et al. 2014). Beta-alanine supplementation appears therefore effective to increase the ‘buffer’ capacity of the organism, and might potentially improve performance during high-intensity exercises (those that elicit a greater diminution of pH).
With the aim of clarifying the ergogenic potential of this supplement, a recent meta-analysis published in the prestigious British Journal of Sports Medicine analysed a total of 40 studies and almost 1500 participants. Results showed that the beta-alanine supplementation significantly improves performance, especially during exercises lasting from 1 to 10 minutes (Saunders et al. 2017). Thus, these results confirm those obtained by a previous meta-analysis that reported improvements of around 3% with the intake of this supplement (Hobson et al. 2012).
Several specific studies have also shown promising benefits of beta-alanine supplementation on endurance performance. For instance, a recent study (Santana et al. 2018) observed that the intake of this supplement (5 g/day) during 23 days reduces the time needed to complete a 10-km running race compared to the intake of a placebo (those ingesting beta-alanine improved their time by 2 minutes 30 seconds, whereas those ingesting the placebo improved only one minute). On the other hand, another study (Van Thienen et al. 2009) assessed the effects of beta-alanine supplementation (2-4 g/day for 8 weeks) on a 10-minute time trial and a final 30-second sprint performed under fatigue (after a simulated race of 110 km). Their results showed that, although the power output achieved during the time trial was similar between the placebo and the beta-alanine groups (~300W), the latter improved their peak and mean power during the final sprint (11 and 5% more, respectively, compared to the placebo).
In summary, beta-alanine supplementation has proven to increase muscle carnosine levels, a physiological buffer that prevents from exercise-induced decreases in pH. Moreover, growing evidence supports the benefits of this supplement on performance, especially during high-intensity efforts (1-10 minutes). These results are of great interests not only for short-duration sports, but also for those that require performing high-intensity efforts under fatigue (e.g., during a cycling stage).
References
- Hobson RM, Saunders B, Ball G, et al (2012) Effects of β-alanine supplementation on exercise performance: A meta-analysis. Amino Acids 43:25–37. doi: 10.1007/s00726-011-1200-z
- Santana JO, de Freitas MC, dos Santos DM, et al (2018) Beta-Alanine Supplementation Improved 10-km Running Time Trial in Physically Active Adults. Front Physiol 9:1–6. doi: 10.3389/fphys.2018.01105
- Saunders B, Elliott-Sale K, Artioli GG, et al (2017) β-Alanine supplementation to improve exercise capacity and performance: A systematic review and meta-Analysis. Br J Sports Med 51:658–669. doi: 10.1136/bjsports-2016-096396
- Stegen S, Bex T, Vervaet C, et al (2014) β-Alanine dose for maintaining moderately elevated muscle carnosine levels. Med Sci Sports Exerc 46:1426–1432. doi: 10.1249/MSS.0000000000000248
- Van Thienen R, Van Proeyen K, Eynde B Vanden, et al (2009) β-Alanine improves sprint performance in endurance cycling. Med Sci Sports Exerc 41:898–903. doi: 10.1249/MSS.0b013e31818db708
