Diedrich, D., Davidson, C. J., Zderic, T. W., Wolf, A. J., & Coyle, E. F. (2001). The effect of pre-exercise carbohydrate ingestion on maximal neuromuscular power during moderate intensity exercise. Medicine and Science in Sports and Exercise, 33(5), Supplement abstract 252.

Endurance-trained cyclists (N = 18) ingested either 0.5 g/kg of glucose or sweet placebo 35 minutes before exercising at 90% lactate threshold intensity.

Insulin levels rose and FFA levels declined after ingestion. Plasma glucose fell to hypoglycemic levels by 14 minutes of exercise and remained low until the end of exertion. Ss performed four maximal power tests using the inertial load method during the 15-21 minute period. Power was lower for the CHO than the placebo group.

It was concluded that transient hypoglycemia caused by pre-exercise carbohydrate ingestion may slightly impair maximal neuromuscular power in trained cyclists at certain time points.

Implication. Pre-exercise carbohydrate ingestion impairs sprint performance.

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