Kern, M., Heslin, C. J., & Rezende, R. S. (2004). Metabolic and performance effects of raisins versus sports gel as preexercise feedings in cyclists. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 1174.

This study determined the differences in metabolism and cycling performance after consumption of raisins (a moderate to low glycemic index food) versus a commercial sports gel (a high glycemic index food). Endurance-trained cyclists (M = 4; F = 4) completed two feeding-performance trials in random order. Participants were fed 1g carbohydrate/kg body weight from either raisins or a sports gel 45 minutes before exercise on an electronically braked cycle ergometer (45 min at 75% VO2max). Immediately thereafter, participants completed a 15-minute performance trial in which total power output was determined. Blood was collected before exercise as well as after the 45th minute of exercise to determine serum concentrations of glucose, free fatty acids, triglycerides, lactate, and beta-hydroxy-butyrate.

There was no performance difference between conditions. Serum concentrations of fuel substrates before exercise were similar for the two conditions. After exercise, free fatty acid concentration increased significantly only during the raisin trial. No other differences in blood-borne substrates were detected between the trials. Ss reported no difference in gastrointestinal symptoms between the two trials.

Implication. Raisins provide better nutrition than, are a cheaper alternative to, and have similar performance effects to commercial gel CHO products.

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