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Branched-chain amino acid supplementation improves cycling performance in untrained cyclists

Manaf, F.A., Peiffer, J.J.ORCID: 0000-0002-3331-1177, Maker, G.L.ORCID: 0000-0003-1666-9377 and Fairchild, T.J.ORCID: 0000-0002-3975-2213 (2020) Branched-chain amino acid supplementation improves cycling performance in untrained cyclists. Journal of Science and Medicine in Sport, 24 (4). pp. 412-417.

Link to Published Version: https://doi.org/10.1016/j.jsams.2020.10.014
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Abstract

Objectives

To investigate the effects of acute branched-chain amino acid (BCAA) supplementation on cycling performance and neuromuscular fatigue during a prolonged, self-paced cycling time-trial.

Design

Randomised double-blind counterbalanced crossover.

Methods

Eighteen recreationally active men (mean ± SD; age: 24.7 ± 4.8 years old; body-weight, BW: 67.1 ± 6.1 kg; height: 171.7 ± 4.9 cm) performed a cycling time-trial on an electromagnetically-braked cycle ergometer. Participants were instructed to complete the individualised total work in the shortest time possible, while ingesting either BCAAs (pre-exercise: 0.084 g kg−1 BW; during exercise: 0.056 g kg−1 h−1) or a non-caloric placebo solution. Rating of perceived exertion, power, cadence and heart rate were recorded throughout, while maximal voluntary contraction, muscle voluntary activation level and electrically evoked torque using single and doublet stimulations were assessed at baseline, immediately post-exercise and 20-min post-exercise.

Results

Supplementation with BCAA reduced (287.9 ± 549.7 s; p = 0.04) time-to-completion and ratings of perceived exertion (p ≤ 0.01), while concomitantly increasing heart rate (p = 0.02). There were no between-group differences (BCAA vs placebo) in any of the neuromuscular parameters, but significant decreases (All p ≤ 0.01) in maximal voluntary contraction, muscle voluntary activation level and electrically evoked torque (single and doublet stimulations) were recorded immediately following the trial, and these did not recover to pre-exercise values by the 20 min recovery time-point.

Conclusions

Compared to a non-caloric placebo, acute BCAA supplementation significantly improved performance in cycling time-trial among recreationally active individuals without any notable changes in either central or peripheral factors. This improved performance with acute BCAA supplementation was associated with a reduced rating of perceived exertion.

Item Type: Journal Article
Murdoch Affiliation(s): Psychology, Counselling, Exercise Science and Chiropractic
Publisher: Elsevier BV
Copyright: © 2020 Sports Medicine Australia.
URI: http://researchrepository.murdoch.edu.au/id/eprint/58943
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