No effect of β-alanine on muscle function and kayak performance

TY - JOUR

T1 - No effect of β-alanine on muscle function and kayak performance

AU - Bech, Signe Refsgaard

AU - Nielsen, Tobias Schmidt

AU - Hald, Martin

AU - Jakobsen, Jarl Pors

AU - Nordsborg, Nikolai Baastrup

N1 - CURIS 2018 NEXS 075

PY - 2018/3/1

Y1 - 2018/3/1

N2 - Purpose If β-alanine supplementation counteracts muscular fatigue development or improves athletic performance was investigated. Methods Elite kayak rowers (10 men and 7 women) were supplemented with either 80 mg·kg -1 body mass·d -1 of β-alanine or placebo for 8 wk. Muscular fatigue development was investigated by applying a 2-min elbow flexor maximal voluntary contraction (MVC). EMG was recorded continuously, and voluntary activation was determined 30, 60, 90, and 115 s into the 2-min MVC. In addition, performance was evaluated as 1000-m and 5 × 250-m kayak ergometer rowing. Results Force reduction during the 2-min MVC was similar before and after supplementation with β-alanine (30.9% ± 10.3% vs 36.0% ± 14.1%) and placebo (35.5% ± 7.7% vs 35.1% ± 8.0%). No time effect was apparent in voluntary activation during the 2-min MVC. In addition, there was no detectable effect of β-alanine supplementation on 1000-m kayak ergometer performance (β-alanine: 0.26% ± 0.02% vs placebo: -0.18% ± 0.02%) or accumulated 5 × 250-m time (β-alanine: -1.0% ± 0.3% vs placebo: -1.0% ± 0.2%). In 5 × 250 m, mean power output was reduced to a similar extent from first to fifth interval before and after supplementation with β-alanine (23% ± 11% vs 22% ± 10%) and placebo (26% ± 13% vs 20% ± 5%). Conclusions Two-minute MVC characteristics are unaffected by β-alanine supplementation in elite kayakers, and likewise, both a 1000-m kayak ergometer time trial lasting 4-5 min and a 5 × 250-m repeated sprint ability were unaltered by supplementation.

AB - Purpose If β-alanine supplementation counteracts muscular fatigue development or improves athletic performance was investigated. Methods Elite kayak rowers (10 men and 7 women) were supplemented with either 80 mg·kg -1 body mass·d -1 of β-alanine or placebo for 8 wk. Muscular fatigue development was investigated by applying a 2-min elbow flexor maximal voluntary contraction (MVC). EMG was recorded continuously, and voluntary activation was determined 30, 60, 90, and 115 s into the 2-min MVC. In addition, performance was evaluated as 1000-m and 5 × 250-m kayak ergometer rowing. Results Force reduction during the 2-min MVC was similar before and after supplementation with β-alanine (30.9% ± 10.3% vs 36.0% ± 14.1%) and placebo (35.5% ± 7.7% vs 35.1% ± 8.0%). No time effect was apparent in voluntary activation during the 2-min MVC. In addition, there was no detectable effect of β-alanine supplementation on 1000-m kayak ergometer performance (β-alanine: 0.26% ± 0.02% vs placebo: -0.18% ± 0.02%) or accumulated 5 × 250-m time (β-alanine: -1.0% ± 0.3% vs placebo: -1.0% ± 0.2%). In 5 × 250 m, mean power output was reduced to a similar extent from first to fifth interval before and after supplementation with β-alanine (23% ± 11% vs 22% ± 10%) and placebo (26% ± 13% vs 20% ± 5%). Conclusions Two-minute MVC characteristics are unaffected by β-alanine supplementation in elite kayakers, and likewise, both a 1000-m kayak ergometer time trial lasting 4-5 min and a 5 × 250-m repeated sprint ability were unaltered by supplementation.

KW - Kayak ergometer

KW - VO2

KW - MVC

KW - Twitch force

KW - EMG

U2 - 10.1249/MSS.0000000000001447

DO - 10.1249/MSS.0000000000001447

M3 - Journal article

C2 - 28991036

SN - 0195-9131

VL - 50

SP - 562

EP - 569

JO - Medicine and Science in Sports and Exercise

JF - Medicine and Science in Sports and Exercise

IS - 3

ER -