A Low Carbohydrate�Protein Supplement Improves Endurance Performance in Female Athletes

• Autores: Erin McCleave, Lisa Ferguson-Stegall, Zhenping Ding, Phillip G. Doerner, Bei Wang, Lynne Kammer, John L. Ivy
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 25, Nº. 4, 2011, págs. 879-888
• Idioma: inglés
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• Dialnet Métricas: 1 Cita
• Resumen

  • The purpose of this study was to investigate if a low mixed carbohydrate (CHO) plus moderate protein (PRO) supplement, provided during endurance exercise, would improve time to exhaustion (TTE) in comparison to a traditional 6% CHO supplement. Fourteen (n = 14) trained female cyclists and triathletes cycled on 2 separate occasions for 3 hours at intensities varying between 45 and 70% [latin capital V with dot above]O2max, followed by a ride to exhaustion at an intensity approximating the individual's ventilatory threshold average 75.06% [latin capital V with dot above]O2max. Supplements (275 mL) were provided every 20 minutes during exercise and were composed of a CHO mixture (1% each of dextrose, fructose, and maltodextrin) + 1.2% PRO (CHO + PRO) or 6% dextrose only (CHO). The TTE was significantly greater with CHO + PRO in comparison to with CHO (49.94 ± 7.01 vs. 42.36 ± 6.21 minutes, respectively, p < 0.05). Blood glucose was significantly lower during the CHO + PRO trial (4.07 ± 0.12 mmol·L-1) compared to during the CHO trial (4.47 ± 0.12 mmol·L-1), with treatment × time interactions occurring from 118 minutes of exercise until exhaustion (p < 0.05). Results from the present study suggest that the addition of a moderate amount of PRO to a low mixed CHO supplement improves endurance performance in women above that of a traditional 6% CHO supplement. Improvement in performance occurred despite CHO + PRO containing a lower CHO and caloric content. It is likely that the greater performance seen with CHO + PRO was a result of the CHO-PRO combination and the use of a mixture of CHO sources.