Too, B. W., Cicai, S., Hockett, K. R., Applegate, E., Davis, B. A., & Casazza, G. A. (2012). Effect of a natural versus commercial product on running performance and gastrointestinal tolerance. Presentation 2361 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

red line

This study examined the effects of raisins and chews on running performance and gastrointestinal tolerance in male runners (N = 11). Ss completed three randomized trials (raisins, chews, and water only) separated by 7 days. Each trial consisted of 80-min submaximal (75%VO2max) running followed by a 5-km time-trial. Heart rate, respiratory exchange ratio, glucose, lactate, free fatty acids, glycerol, insulin, electrolytes, creatine kinase, GI symptoms, and rating of perceived exertion were recorded every 20 minutes during the submaximal trial and at the end of the time-trial. Whole body muscle soreness and fatigue were also measured.

Muscle soreness and fatigue, VO2, heart rate, electrolytes, lactate, and rating of perceived exertion did not differ between treatments. Respiratory exchange ratio and blood glucose were significantly higher during the carbohydrate treatments. Plasma creatine kinase was higher for raisins compared to the other two conditions. Time to complete the time-trial was shorter for both carbohydrate treatments. GI disturbance was mild for all treatments.

Implication. Both the raisins and chews maintained high blood glucose levels and improved running performance compared to water only. Running performance between the raisins and chews were similar with no significant GI differences.

Return to Table of Contents for this issue.

red line