Effects Of β-alanine Supplementation On Human Skeletal Muscle Contractile Properties And Voluntary Muscle Performance

Stannard, Rebecca L., Hannah, Ricci, Minshull, Claire , Artioli, Guilherme, Harris, Roger and Sale, Craig (2016) Effects Of β-alanine Supplementation On Human Skeletal Muscle Contractile Properties And Voluntary Muscle Performance. In: 21st Annual Congress of the European College of Sport Science: Crossing Borders through Sport Science, 6-9 July 2016, University of Vienna, Vienna, Austria.

Full content URL: https://doi.org/10.1249/01.mss.0000477334.63406.fe

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Item Type:Conference or Workshop contribution (Presentation)
Item Status:Live Archive

Abstract

Elevated intramuscular carnosine content achieved via β-alanine supplementation (BA) can improve human exercise performance. This is most likely due to improved intracellular pH regulation and/or enhanced muscle contractile properties as a result of improved calcium (Ca2+) sensitivity.

PURPOSE: To examine the effects of BA on in vivo human skeletal muscle contractile properties and voluntary performance.

METHODS: Twenty-three participants completed two experimental sessions, before and after 28 d supplementation with 6.4 g·d-1 of β-alanine (n=12; 26 ± 7 y) or placebo (PLA; n=11; 25 ± 5 y). Knee extensor force and surface electromyography (EMG) were recorded during a series of voluntary and electrically-evoked (nerve and superficial muscle stimulation) contractions. Data were analysed using repeated measures ANOVA; significance was accepted at P<0.05.

RESULTS: BA had no effect on force-frequency relationship (1 s stimulation, 1-100Hz), or peak force during evoked twitches or octets (8 pulses, 300 Hz). No changes in evoked twitch electromechanical delay (EMD) or time-to-peak tension were shown, although resting and potentiated twitch half-relaxation time (HRT) decreased by 12% and 7% after BA (Table 1). BA did not alter maximal or explosive force (25 ms intervals up to 150 ms from onset) during voluntary contractions.

CONCLUSION: BA had no effect on the force-frequency relationship, supported by lack of change in twitch force data, implying a lack of influence of muscle carnosine elevation on Ca2+ sensitivity. Nevertheless, HRT was reduced after BA, which may be explained by improved cross-bridge detachment rates or reuptake of Ca2+, potentially providing important implications for the efficiency of muscle contraction.

Keywords:supplementation
Subjects:C Biological Sciences > C600 Sports Science
Divisions:College of Social Science > School of Sport and Exercise Science
ID Code:49276
Deposited On:24 May 2022 15:05

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