MEDIUM-CHAIN TRIGLYCERIDES DO NOT IMPROVE CYCLING PERFORMANCE IN FEMALES

Eimer, A. J., Webster, M. J., Boyd, J. C., Eschbach, L. C., McArthur, P. D., Zoeller, R. F., Krebs, G. V., & Angelopoulos, T. J. (1999). Physiological and performance responses of female endurance cyclists to supplementation with medium-chain triglycerides and carbohydrate. Medicine and Science in Sports and Exercise, 31(5), Supplement abstract 459.

The purpose of this study was to compare the physiological and performance responses of female endurance cyclists to supplementation with either a 10% CHO solution or a combination of CHO (10%) and medium-chain triglycerides (4.3%). Previous research reported that medium-chain triglycerides (MCT) improved cycling performance and CHO metabolism in males. Considering the reported gender differences in fat and CHO metabolism, this study was conducted to evaluate gender differences.

Trained female cyclists (N = 8) cycled for two hours at steady-state (~58% VO2max) and then performed a simulated 10-Km time trial under each supplement condition. Five minutes before the exercise, 400 ml of the target solution was ingested. During the 2-h ride, 100 ml of the assigned solution was consumed every 10 minutes.

Subjects varied significantly for RPE, heart rate, and respiratory exchange ratio. There were no significant differences for any measure (RPE, HR, RER, lactate, glucose, performance) between the conditions.

Implication. Medium-chain triglyceride supplementation did not enhance performance or substrate utilization in female cyclists when CHO supplementation was used.

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