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

Abstract

PurposeIn fresh muscle, supplementation with the rate-limiting precursor of carnosine, β-alanine (BA), results in a decline in muscle half-relaxation time (HRT) potentially via alterations to calcium (Ca2+) handling. Accumulation of hydrogen cation (H+) has been shown to impact Ca2+ signalling during muscular contraction, carnosine has the potential to serve as a cytoplasmic regulator of Ca2+ and H+ coupling, since it binds to both ions. The present study examined the effect of BA supplementation on intrinsic in-vivo isometric knee extensor force production and muscle contractility in both fresh and fatigued human skeletal muscle assessed during voluntary and electrically evoked (nerve and superficial muscle stimulation) contractions.MethodsTwenty-three males completed two experimental sessions, pre- and post- 28 day supplementation with 6.4 g.day−1 of BA (n = 12) or placebo (PLA; n = 11). Isometric force was recorded during a series of voluntary and electrically evoked knee extensor contractions.ResultsBA supplementation had no effect on voluntary or electrically evoked isometric force production, or twitch electromechanical delay and time-to-peak tension. There was a significant decline in muscle HRT in fresh and fatigued muscle conditions during both resting (3 ± 13%; 19 ± 26%) and potentiated (1 ± 15%; 2 ± 20%) twitch contractions.ConclusionsThe mechanism for reduced HRT in fresh and fatigued skeletal muscle following BA supplementation is unclear. Due to the importance of muscle relaxation on total energy consumption, especially during short, repeated contractions, BA supplementation may prove to be beneficial in minimising contractile slowing induced by fatigue.Trial registrationThe trial is registered with Clinicaltrials.gov, ID number NCT02819505.

Comparison of sustained-release and rapid-release β-alanine formulations on changes in skeletal muscle carnosine and histidine content and isometric performance following a muscle-damaging protocol

“…Ahlborg et al (1972) predicted the time to exhaustion at 45% of maximal voluntary contraction to be about 80 s, whereas the hold-time of participants in Derave et al (2007) study lasted longer than 175 s. Exercise of longer duration utilizes the oxidative system for metabolic energy production to a greater extent than shorter-duration exercise, leading to lower H + accumulation. Furthermore, our results contradict with those of Kendrick et al (2008) who reported no improvement in quadriceps isokinetic force after β-alanine supplementation (6.4 g day −1 for 10 weeks), and Hannah et al (2015) and Jones et al (2017), who reported no change in quadriceps maximal voluntary isometric force production or the force-frequency relationship after β-alanine supplementation (6.4 g day −1 for 28 days). The differences in findings may be related to the exercises utilized, as the isometric protocols by Kendrick et al (2008), Derave et al (2007), Hannah et al (2015) and Jones et al (2017) may not have elicited the extent of fatigue to maximize the benefits achieved from a greater buffering capacity.…”

“…Furthermore, our results contradict with those of Kendrick et al (2008) who reported no improvement in quadriceps isokinetic force after β-alanine supplementation (6.4 g day −1 for 10 weeks), and Hannah et al (2015) and Jones et al (2017), who reported no change in quadriceps maximal voluntary isometric force production or the force-frequency relationship after β-alanine supplementation (6.4 g day −1 for 28 days). The differences in findings may be related to the exercises utilized, as the isometric protocols by Kendrick et al (2008), Derave et al (2007), Hannah et al (2015) and Jones et al (2017) may not have elicited the extent of fatigue to maximize the benefits achieved from a greater buffering capacity. Carnosine is known to enhance intracellular buffering of H + (Abe 2000), improving performance particularly during high-intensity anaerobic exercise, and β-alanine supplementation does not appear to have an effect on maximal strength production (Hoffman et al 2008;Kendrick et al 2008).…”

“…Carnosine acts as a buffer of H + , decreasing exercise-induced acidosis and, therefore, prolonging high-intensity exercise duration (Abe 2000). Additionally, recent investigations by Hannah et al (2015) and Jones et al (2017) have suggested that β-alanine supplementation and subsequent increases in muscle carnosine content can result in a reduction in muscle relaxation time, which may be especially beneficial for repeated bouts of exercise. This can potentially augment force production and provide a further mechanism for the improvements in exercise performance with β-alanine supplementation.…”

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

“…Exercises requiring maximal strength and power or muscular endurance likely do not stress the anaerobic system enough to elicit a significant elevation in H + concentrations. Furthermore, most studies have reported no significant increases in maximal strength and power or muscular endurance (lasting less than 60 sec in duration) after BA supplementation (Hannah et al 1985;Hoffman et al 2008b;Kendrick et al 2008;Jones et al 2017).…”

Histidine in Health and Disease: Metabolism, Physiological Importance, and Use as a Supplement

“…Several original and review articles have described the positive effects of long-term beta-alanine supplementation on muscle performance [92][93][94][95][96], and chronic beta-alanine supplementation is a popular ergogenic strategy. It should be noted that a substantial decrease in the HIS content (~30%) in muscles and plasma after beta-alanine supplementation has been reported [89].…”