A systematic review with meta-analysis was conducted to analyze the effect of carbohydrate (CHO) intake during exercise and some variables that could moderate this effect on endurance performance. We included 136 studies examining the effect of CHO ingestion during endurance exercise in the meta-analysis. The overall effect on performance showed a significant increase after CHO intake compared to the placebo/control groups. A larger effect of CHO consumption is observed in time to exhaustion than in time trials performance test. Moreover, the effectiveness of CHO supplementation was greater the longer the duration of the events. Also, there seems to be a higher effect of CHO intake in lower trained than in higher trained participants. In contrast, the magnitude of performance change of CHO intake is not affected by the dosage, ergometer used, the type of intake of the CHO ingestion and the type of CHO. In addition, a lower rate of perceived exertion and higher power and heart rate are significantly associated with the ingestion of CHO during endurance exercise. These results reinforce that acute CHO feeding is an effective strategy for improving endurance performance, especially, in less trained subjects participating in time to exhaustion tests of longer durations.
Keywords: Aerobic; endurance; glucose; glycogen; training.