McConell, G., Kloot, K., Hargreaves, M. (1996). Effect of timing of carbohydrate ingestion on endurance exercise performance. Medicine and Science in Sports and Exercise, 28, 1300-1304.

The effect of carbohydrate (CHO) ingested throughout exercise was compared to CHO ingested late in exercise. Men (N = 8) cycled for two hours at 70% VO2peak. That was followed immediately by a 15-minute performance ride. A 7% CHO solution, a placebo (control), or a placebo for 90 minutes and then a 21% CHO solution were the ingestion treatments.

The best indexes at the start of the 15-minute ride resulted from the continuous 7% CHO regimen. Seven of eight Ss performed best in the 7% condition. Some indexes were no different between the 21% CHO and placebo conditions.

CHO ingestion late in exercise did not improve subsequent performance whereas continuous ingestion of CHO did.

Implication. CHO ingestion spread across exercise at a 7% concentration has a positive effect on subsequence performance.

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