How carbohydrate amount and timing affect metabolism, stomach comfort, and cross-country skiing performance

Ten participants completed four 30-km roller skiing trials with varying carbohydrate ingestion rates and frequencies.

• Low-frequency carbohydrate ingestion led to elevated blood glucose levels at 4 and 19 km but reduced levels at 14 and 29 km compared to high-frequency strategies.
• Higher gastrointestinal discomfort was reported in high carbohydrate intake with low frequency compared to all other trials.
• Low-frequency trials showed lower whole-body lipid oxidation and higher carbohydrate oxidation compared to high-frequency trials.
• Overall performance time did not significantly differ across trials, although it improved with trial order.
• No significant effects were observed from the order of trials on any other measured variables.

Simplified