Effects of an Amino Acid–Carbohydrate Drink on Exercise Performance after Consecutive-Day Exercise Bouts

Rebecca A. Skillen ^[1] ; Massimo Testa ^[2] ; Elizabeth Applegate ; Eric A. Heiden ^[2] ; Andrea J. Fascetti ; Gretchen A. Casazza ^[3]
1. [1] University of California System
  
  University of California System
  
  Estados Unidos
2. [2] Hospital Ortopédico de Passo Fundo
  
  Hospital Ortopédico de Passo Fundo
  
  Brasil
3. [3] California State University, Sacramento
  
  California State University, Sacramento
  
  Estados Unidos
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Localización: International journal of sport nutrition and exercise metabolism, ISSN 1526-484X, ISSN-e 1543-2742, Vol. 18, Nº. 5, 2008, págs. 473-492
Idioma: inglés
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Resumen
- This study examined the effect of amino acids in a carbohydrate beverage on cycling performance. Twelve male athletes (28.5 pp2.1 yr) cycled at 75% VO2peak for 90 min followed by a ride to exhaustion at 85% VO2peak, before (T1) and on 2 consecutive days (T2 and T3) after 2 weeks of supplementation with 3.6% carbohydrate plus 1% amino acids (AA) or 4.6% carbohydrate-only (CHO) isocaloric beverages. Muscle damage was assessed by plasma creatine kinase (CK), and muscle fatigue by changes in vertical jump pre- to postexercise. Muscle soreness, overall fatigue, and changes in mood state were assessed using questionnaires. Plasma CK was lower for AA in T3 (214.0 ss13.5 vs. 485.9 11191.4 U/L immediately post, 213.9 ÷ 13.1 vs. 492.0 ÷ 199.4 U/L 5 hr post, and 194.9 ÷ 17.9 vs. 405.9 ÷ 166.6 U/L 24 hr postexercise in AA and CHO, respectively). Time to exhaustion decreased from T2 to T3 only in CHO (10.9 ÷ 2.5 to 12.6 ÷ 3.2 vs. 13.8 ÷ 2.8 to 7.8 ÷ 1.5 min in AA and CHO, respectively). Vertical-jump change from pre- to postexercise was greater in T3 for the CHO treatment. Total fatigue score and mood disturbance decreased significantly only with AA in T3. The addition of AA to a carbohydrate beverage after consecutive-day exercise bouts reduced muscle damage as indicated by CK levels, decreased fatigue, and maintained exercise performance compared with consuming carbohydrate alone.