Effects of Twenty-Eight Days of Beta-Alanine and Creatine Monohydrate Supplementation on the Physical Working Capacity at Neuromuscular Fatigue Threshold

• Autores: Jeffrey R. Stout, Joel T. Cramer, Michelle Mielke, Joseph O'Kroy, Don J. Torok
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 20, Nº. 4, 2006, págs. 928-931
• Idioma: inglés
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• Dialnet Métricas: 6 Citas
• Resumen

  • Stout, J.R., J.T. Cramer, M. Mielke, J. O'Kroy, D.J. Torok, and R.F. Zoeller. Effects of twenty-eight days of beta-alanine and creatine monohydrate supplementation on the physical working capacity at neuromuscular fatigue threshold. J. Strength Cond. Res. 20(4):928-931. 2006.-The purpose of this study was to examine the effects of 28 days of beta-alanine (b-Ala) and creatine monohydrate (CrM) supplementation on the onset of neuromuscular fatigue by using the physical working capacity at neuromuscular fatigue threshold (PWCFT) test in untrained men. Fifty-one men (mean age ± SD = 24.5 ± 5.3 years) volunteered to participate in this 28-day, double-blind, placebo-controlled study and were randomly assigned to 1 of 4 groups: placebo (PLA; 34 g dextrose; n = 13), CrM (5.25 g CrM plus 34 g dextrose; n = 12), b-Ala (1.6 g b-Ala plus 34 g of dextrose; n = 12), or b-Ala plus CrM (CrBA; 5.25 g CrM plus 1.6 g b-Ala plus 34 g dextrose; n = 14). The supplement was ingested 4 times per day for 6 consecutive days, then twice per day for 22 days before posttesting. Before and after the supplementation, subjects performed a continuous incremental cycle ergometry test while a surface electromyographic signal was recorded from the vastus lateralis muscle to determine PWCFT. The adjusted mean posttest PWCFT values (covaried for pretest PWCFT values) for the b-Ala and CrBA groups were greater than those for the PLA group (p 0.05). However, there were no differences between the CrM vs. PLA, CrBA vs. b-Ala, CrM vs. b-Ala, or CrM vs. CrBA groups (p > 0.05). These findings suggested that b-Ala supplementation may delay the onset of neuromuscular fatigue. Furthermore, there appeared to be no additive or unique effects of CrM vs. b-Ala alone on PWCFT.