Rauch, H. G., Hawley, J. A., Woodey, M., Noakes, T. D., & Dennis, S. C. (1999). Effects of ingesting a sports bar versus glucose polymer on substrate utilization and ultra-endurance performance. International Journal of Sports Medicine, 20, 252-257.

The effect of ingesting a sports bar (fat 7 g; protein 14 g; CHO 19 g) on ultra-endurance cycling performance was compared to that of ingesting an equal-calorie amount of CHO. Highly trained endurance cyclists (N = 7) were tested on two occasions, seven days apart. The testing consisted of riding for 5.5 hours at 50% peak power output, followed by a 400 kJ time trial.

Rates of fat oxidation were significantly greater at the end of the submaximum ride when the sports bar was ingested than under the CHO condition. Two Ss failed to complete the time trial ride under the sports bar condition but all Ss completed it under the CHO condition.

Implication. Ingestion of a sports bar increased fat metabolism but impaired subsequent high-intensity performances.

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