McClaughry, A. C., Harger, S., Gaskill, S. E., & Ruby, B. C. (2005). Effects of carbohydrate feeding on muscle glycogen and substrate oxidation during extended exercise in females. Medicine and Science in Sports and Exercise, 37(5), Supplement abstract 1613.

Moderately trained females (N = 6) ingested either a CHO (0.6 g/kg of 20% maltodextrin) or placebo each hour. Ss completed 10, 60-minute bouts of exercise at 70% ventilatory threshold. Each 60-minute bout consisted of 9 minutes of self-selected intensity on a double-poling arm ergometer, 19 minutes on a cycle ergometer, 20 minutes on a treadmill, and a 10-minute rest and feeding period.

Whole body CHO oxidation was significantly higher and rates of muscle glycogenolysis lower on the treadmill in the CHO trial than in the placebo condition. Blood glucose and RPE were similar in both conditions.

Implication. Females benefit from intermittent carbohydrate feedings in very long exercises (~10 hours).

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