The effect of carbohydrate mouth rinse on time to exhaustion and muscle electromyographic activity of female athletes during a sub-maximal cycling task

A growing body of evidence suggests that carbohydrate mouth rinse (CMR) can enhance endurance performance. This study aimed to investigate the effect of CMR on time to exhaustion and muscle electromyographic activity of female athletes during one bout of sub-maximal cycling task.

Ten active females visited the laboratory on 3 different occasions. In the first visit, peak power output was measured and within the second and third visit, each subject completed one bout of cycling task at 65% of peak power output until exhaustion under either CMR or placebo condition. Blood lactate and glucose were measured before and immediately after the termination of the task. During the task, heart rate, RPE, and electrical activity of the right Vastus lateralis (VL) and Rectus femoris (RF) muscles were recorded within the specified time.

The results showed a significant improvement in time to exhaustion under CMR compared to the placebo condition (p=0.007). The electrical activity of the VL muscle was significantly higher under CMR compared to the placebo condition (p=0.0001). On the other hand, no significant difference was seen in the electrical activity of the Rectus Femoris muscle, blood glucose, lactate, RPE, and heart rate between the two conditions (p˃0.05).

In conclusion, these results indicated that CMR could be seen as a strategy to boost endurance performance in female athletes. Besides, it seems that such an effect is mediated by CNS-related mechanisms rather than those related to carbohydrate metabolic pathways.