Effect of Preexercise Glycemic-Index Meal on Running When CHO-Electrolyte Solution Is Consumed During Exercise

• Autores: Stephen H.S. Wong, Oi Wan Chan, Ya Jun Chen, Heng Long Hu, Ching Wan Lam, Pak Kwong Chung
• Localización: International journal of sport nutrition and exercise metabolism, ISSN 1526-484X, ISSN-e 1543-2742, Vol. 19, Nº. 3, 2009, págs. 222-242
• Idioma: inglés
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• Dialnet Métricas: 2 Citas
• Resumen

  • Purpose: This study examined the effect of consuming carbohydrate- (CHO) electrolyte solution on running performance after different-glycemic-index (GI) meals. Methods: Nine men completed 3 trials in a randomized counterbalanced order, with trials separated by at least 7 days. Two hours before the run after an overnight fast, each participant consumed a high-GI (GI = 83) or low-GI (GI = 36) CHO meal or low-energy sugar-free Jell-O (GI = 0, control). The 2 isocaloric GI meals provided 1.5 g available CHO/kg body mass. During each trial, 2 ml/kg body mass of a 6.6% CHO-electrolyte solution was provided immediately before exercise and every 2.5 km after the start of running. Each trial consisted of a 21-km performance run on a level treadmill. The participants were required to run at 70% VO2max during the first 5 km of the run. They then completed the remaining 16 km as fast as possible. Results: There was no difference in the time to complete the 21-km run (high-GI vs. low-GI vs. control: 91.1 ± 2.0 vs. 91.8 ± 2.2 vs. 92.9 ± 2.0 min, n.s.). There were no differences in total CHO and fat oxidation throughout the trials, despite differences in preexercise blood glucose, serum insulin, and serum free-fatty-acid concentrations. Conclusion: When a CHO-electrolyte solution is consumed during a 21-km run, the GI of the preexercise CHO meal makes no difference in running performance.