The effect of galactose ingestion on affect and perceived exertion in recreationally active females

The beneficial effects of acute carbohydrate (CHO) supplementation on exercise performance have been well described. Also reported is the attenuation of perceived exertion and enhancement of affect during prolonged exercise following CHO ingestion. However, no studies to date have assessed the impact of the type of CHO ingested on affective responses during moderate intensity exercise, lasting 60 min or less. Therefore, the aim of the present study was to investigate the effects of consuming a galactose (GAL) CHO drink versus a glucose (GLU) CHO or placebo (PLA) drink before and during exercise on affect and perceived exertion. Nine recreationally active females undertook three trials, each consisting of running for 60 min at 65% VO2max followed immediately by a 90 min rest period. Prior to (300 ml) and at every 15 min during exercise (150 ml), participants consumed either a GLU or GAL drink each containing 45 g of CHO, or an artificially-sweetened PLA drink. Ratings of pleasure-displeasure and perceived activation were measured throughout exercise and the rest period and measures of perceived exertion were measured during exercise. Plasma glucose and serum insulin were significantly greater throughout exercise and rest following the GLU trial compared with the GAL and PLA trials (P < 0.05). Measures of perceived activation and pleasure-displeasure were not enhanced nor RPE reduced as a result of ingestion of a CHO solution. In conclusion, the GAL beverage elicited a more favourable metabolic profile in the exercising females but this did not translate into an enhanced affective profile. Indeed, CHO ingestion had no noticeable effect on the assessed psychological indices during 60 min of moderate-intensity exercise in females. It is suggested that the maintenance of a positive affective profile may be explained more by the level of hydration as opposed to fuel availability. Therefore, those seeking to use beverages containing CHO to enhance their exercise experience may take note of these findings as this practise appears unjustified.