Seven male competitive road cyclists were studied to assess their self‐selected dietary carbohydrate intake and to determine whether immediate post‐training glucose supplementation could improve cycling performance 24 hours later. A random order, double‐blind crossover design was used. Subjects cycled to exhaustion at 75% maximal oxygen uptake VO2maxand consumed a 12% maltodextrin (3.0 g CHO‐kg‐1body weight) (CHO) or placebo (PLA) solution immediately postexercise. After 24 hours, the subjects cycled at 70% VO2maxfor 1 hour and then at 85% VO2maxuntil exhaustion. Two weeks separated the CHO and PLA tests. The unsupplemented diet in each experimental condition contained 52±6% kilocalories as carbohydrate. This was elevated to 68±6% in the CHO condition. Five of the seven cyclists significantly increased their cycling time to exhaustion in the CHO condition (CHO, 73±9 minutes; PLA, 64±11 minutes). These results indicate that the normal diet of these cyclists contained a suboptimal amount of carbohydrate for optimal performance in the task they set themselves. An immediate post‐training CHO supplementation seemed to improve the subsequent day's performance in most of the present group of competitive cyclists.