RESUMEN
PURPOSE: If ß-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 body mass·d of ß-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 ß-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 ß-alanine supplementation on 1000-m kayak ergometer performance (ß-alanine: 0.26% ± 0.02% vs placebo: -0.18% ± 0.02%) or accumulated 5 × 250-m time (ß-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 ß-alanine (23% ± 11% vs 22% ± 10%) and placebo (26% ± 13% vs 20% ± 5%). CONCLUSIONS: Two-minute MVC characteristics are unaffected by ß-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.