β-Alanine supplementation enhances human skeletal muscle relaxation speed but not force production capacity

Hannah, Ricci, Stannard, Rebecca Louise, Minshull, Claire , Artioli, Guilherme Giannini, Harris, Roger Charles and Sale, Craig (2015) β-Alanine supplementation enhances human skeletal muscle relaxation speed but not force production capacity. Journal of Applied Physiology, 118 (5). pp. 604-612. ISSN 8750-7587

Full content URL: https://doi.org/10.1152/japplphysiol.00991.2014

Documents
β-Alanine supplementation enhances human skeletal muscle relaxation speed but not force production capacity

Request a copy
[img] PDF
Hannah et al 2015 β-Alanine supplementation enhances human skeletal - Copy.pdf - Whole Document
Restricted to Repository staff only

408kB
Item Type:Article
Item Status:Live Archive

Abstract

PURPOSE: β-alanine (BA) supplementation improves human exercise performance. One possible explanation for this is an enhancement of muscle contractile properties, occurring via elevated intramuscular carnosine resulting in improved calcium sensitivity and handling. This study investigated the effect of BA supplementation on in vivo contractile properties and voluntary neuromuscular performance. METHODS: Twenty-three men completed two experimental sessions, pre- and post-28 days supplementation with 6.4 g·d-1 39 of BA (n = 12) or placebo (PLA; n = 11). During each session, force was recorded during a series of knee extensor contractions: resting and potentiated twitches and octet (8 pulses, 300 Hz) contractions elicited via femoral nerve stimulation; tetanic contractions (1 s, 1 – 100 Hz) via superficial muscle stimulation; and maximum and explosive voluntary contractions. RESULTS: BA supplementation had no effect on the force-frequency relationship, or the force responses (force at 25 ms and 50 ms from onset, peak force) of resting or potentiated twitches, and octet contractions (P > 0.05). Resting and potentiated twitch electromechanical delay and time-to-peak tension were unaffected by BA supplementation (P > 0.05), although half-relaxation time declined by 7-12% (P < 0.05). Maximum and explosive voluntary forces were unchanged after BA supplementation. CONCLUSION: BA supplementation had no effect on evoked force responses, implying that altered calcium sensitivity and/or release are not the mechanisms by which BA supplementation influences exercise performance. The reduced half-relaxation time with BA supplementation might, however, be explained by enhanced reuptake of calcium, which has implications for the efficiency of muscle contraction following BA supplementation.

Keywords:beta-alanine, muscle contractile properties, electrical stimulation, force-frequency relationship
Subjects:C Biological Sciences > C600 Sports Science
Divisions:College of Social Science > School of Sport and Exercise Science
ID Code:49268
Deposited On:24 May 2022 14:11

Repository Staff Only: item control page