Effects of Carbohydrate and Branch-Chain Amino Acid Ingestion on Intermittent, High Intensity Running 720

Abstract

Research is beginning to accumulate regarding a possible ergogenic effect of carbohydrate feedings on intermittent high intensity exercise of relatively short duration (= 60 min). Branched chain amino acid (BCAA) supplementation has also been suggested to delay fatigue during prolonged exercise but the effect has not been tested in other exercise situations. Therefore, the purpose of this study was to examine the effects of carbohydrate and BCAA ingestion before and during shuttle running to fatigue. Eight subjects performed three exercise trials consisting of 5 × 15 min sessions of shuttle running (intervals of walking, sprinting, and running at 55% & 95% VO2max) followed by intermittent running (at 55% & 95% VO2max) to fatigue. Trials were completed in a double-blind counterbalanced fashion. Treatments included: flavored water placebo (P), carbohydrate 1h before (5ml/kg; 18%), immediately before and during exercise(2 ml/kg; 6%) (CHO), and carbohydrate+BCAA (7g at 1h and immediately before exercise). Results show that subjects ran longer when fed either CHO or CHO+BCAA as compared to P (CHO 9.65±2.07, CHO+BCAA 9.00±2.26, P 6.36±1.63 min; mean±SE; p<0.05). CHO & CHO+BCAA had higher glucose and lower FFA concentrations that P (p<0.05). These results indicate that drinking carbohydrate solutions 1h before and during exercise improves running capacity during exercise that imitates various sports, and that the addition of BCAA does not further enhance this effect.