Mid Sweden University

This study investigated carbohydrate ingestion of varied doses and frequencies during a simulated cross-country skiing time trial. Ten men and three women (age: 30±7years; VO2max: 59.6±5.7 mL/kg/min) completed four, 30-km classic technique roller skiing time trials on a treadmill. A 1:1 maltodextrin-fructose carbohydrate solution was provided at high (2.4 g/min; HC) and moderate (1.2 g/min; MC) ingestion rates, each at high (six feeds;HF) and low (two feeds; LF) frequencies. In the LF trials, blood glucose was elevated following carbohydrate ingestion (at 4 and 19 km) but was reduced at 14 and 29 km compared with HF strategies (P≤0.05). Gastrointestinal discomfort was higher in HC-LF compared with all other trials (P≤0.05). Whole-body lipid oxidation was lowerand carbohydrate oxidation was higher in LF compared with HF trials (P≤0.05). While performance time was not significantly different between trials (140:11±15:31,140:43±17:40, 139:12±15:32 and 140:33±17:46 min:sin HC-HF, HC-LF, MC-HF, and MC-LF, respectively;P>0.05), it was improved with trial order (P<0.001). There was no effect of order on any other variable (P>0.05). Altering carbohydrate dose or frequency does not affect cross-country ski performance. However, low-frequency carbohydrate ingestion resulted in poorer maintenance of euglycemia, reduced lipid oxidation, and increased gastrointestinal discomfort.