Carnosine: from exercise performance to health

Abstract

Carnosine was first discovered in skeletal muscle, where its concentration is higher than in any other tissue. This, along with an understanding of its role as an intracellular pH buffer has made it a dipeptide of interest for the athletic population with its potential to increase high-intensity exercise performance and capacity. The ability to increase muscle carnosine levels via β-alanine supplementation has spawned a new area of research into its use as an ergogenic aid. The current evidence base relating to the use of β-alanine as an ergogenic aid is reviewed here, alongside our current thoughts on the potential mechanism(s) to support any effect. There is also some emerging evidence for a potential therapeutic role for carnosine, with this potential being, at least theoretically, shown in ageing, neurological diseases, diabetes and cancer. The currently available evidence to support this potential therapeutic role is also reviewed here, as are the potential limitations of its use for these purposes, which mainly focusses on issues surrounding carnosine bioavailability.

Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males

“…Beta-alanine supplementation (e.g., 3–6 g/day for 2–4 weeks) has been reported to increase muscle carnosine levels, buffer acidity, and enhance exercise performance [6, 21–24]. Research has indicated that length of time of supplementation affects the impact that beta-alanine supplementation has on muscle carnosine levels and potential ergogenic benefit [27, 60–62]. Thus, it is possible that consuming 3 g/day of beta-alanine for 8-weeks could have provided ergogenic benefit during resistance-training.…”

Effect of β-alanine supplementation on 20 km cycling time trial performance

“…However, the strength of the currently available evidence to support the e ects of carnosine on calcium handling is limited 2,9 , with only one study 3 being conducted on human muscle bres. If calcium handling were the main mechanism for an e ect of elevated muscle carnosine on exercise performance, signi cant e ects of β-alanine supplementation would be expected across a wider range of exercise performance tests than have currently been shown 2,9 . Whilst the present study was not designed to examine the mechanisms related to increased exercise performance as a result of elevated muscle carnosine levels, the lack of an e ect of β-alanine would be consistent with the lack of an e ect of carnosine on calcium handling.…”

“…As such, the expansion of the imidazole ring content in human skeletal muscle through an increase in the muscle carnosine concentration o ers a means to increase muscle bu ering capacity and high intensity exercise performance and capacity [1][2] . Other potential physiological roles of carnosine, such as increased calcium sensitivity [3][4] and antioxidant capacity [5][6] might also contribute to a positive e ect on exercise capacity and performance, although literature is inconclusive 7 .…”

β-alanine supplementation improves in-vivo fresh and fatigued skeletal muscle relaxation speed

“…BA supplementation has been shown to consistently increase human skeletal muscle carnosine concentrations, and by an equal amount in both type I and II muscle fibres (Hill et al 2007), with increases of 40–80% evident depending upon dose (3.2–6.4 g day −1 ) and duration of administration (4–10 weeks) (Harris et al 2006; Hill et al 2007). Increasing skeletal muscle carnosine concentrations via BA supplementation in both upper and lower limbs has consistently been shown to benefit high-intensity exercise capacity and performance, as highlighted by several reviews (Sale et al 2010, 2013) and a recent meta-analysis (Hobson et al 2012). …”