Carbohydrate ingestion during prolonged high-intensity intermittent exercise: impact on affect and perceived exertion

This study was designed to determine the effects of ingesting a carbohydrate (CHO) solution on affective states and rating of perceived exertion (RPE) during prolonged intermittent high-intensity exercise. Seventeen male soccer players completed a prolonged intermittent high-intensity exercise protocol for 90 min on two occasions, separated by at least 7 days. Participants consumed either a 6.4% CHO (0.6 g/kg body mass (BM)/h) or an artificially sweetened placebo (PLA) solution immediately before (8 mL/kg BM) and every 15 min (3 mL/kg BM) during exercise in a double-blind, counterbalanced design. Pleasure-displeasure, perceived activation, RPE and plasma glucose concentration was assessed. The results showed that compared with the CHO trial, perceived activation were lower in the placebo trial during the last 30 min of exercise and this was accompanied by lowered plasma glucose concentrations. In the CHO trial, RPE was maintained in the last 30 min of exercise but carried on increasing in the PLA trial. Therefore, CHO ingestion during prolonged high-intensity exercise appears to elicit an enhanced perceived activation profile that may impact upon task persistence and performance. This finding is in addition to the physiological and metabolic benefits of the exogenous energy supply.