Carbohydrate Mouth Rinsing in the Fed State: Lack of Enhancement of Time-Trial Performance

Abstract

It has been reported previously that mouth rinsing with a carbohydrate-containing solution can improve cycling performance. The purpose of the current study was to investigate the impact of such a carbohydrate mouth rinse on exercise performance during a simulated time trial in a more practical, postprandial setting. Fourteen male endurance-trained athletes were selected to perform 2 exercise tests in the morning after consuming a standardized breakfast. They performed an approximately 1-hr time trial on a cycle ergometer while rinsing their mouths with either a 6.4% maltodextrin solution (CHO) or water (PLA) after every 12.5% of the set amount of work. Borg's rating of perceived exertion (RPE) was assessed after every 25% of the set amount of work, and power output and heart rate were recorded continuously throughout the test. Performance time did not differ between treatments and averaged 68.14 +/- 1.14 and 67.52 +/- 1.00 min in CHO and PLA, respectively (p = .57). In accordance, average power output (265 +/- 5 vs. 266 +/- 5 W,p = .58), heart rate (169 +/- 2 vs. 168 +/- 2 beats/min, p = .43), and RPE (16.4 +/- 0.3 vs. 16.7 +/- 0.3 W, p = .26) did not differ between treatments. Furthermore, after dividing the trial into 8 s, no differences in power output, heart rate, or perceived exertion were observed over time between treatments. Carbohydrate mouth rinsing does not improve time-trial performance when exercise is performed in a practical, postprandial setting.

Mouth Rinsing With Carbohydrate Solutions at the Postprandial State Fail to Improve Performance During Simulated Cycling Time Trials

“…Subjects were not allowed to drink any water during the trials. A 5-s mouth rinse duration was adopted to replicate the large proportion of protocols performed in this area of research (3,10,30,31,38). Thus the only differences observed would be a consequence of the CHO concentration and not methodological discrepancies.…”

The effect of carbohydrate mouth rinse on a 30-minute arm cranking performance

“…Not all studies using CHO mouth rinse have reported significant improvements in performance (Beelen et al, 2009), however the majority of these studies did observe improvements in performance just not with statistical significance. More importantly, no study to date has reported a decrease in performance .…”

“…Different methodological factors have been shown to influence the effect that CHO mouth rinse has on performance, such as the duration of the solution being in the mouth (Pottier et al, 2010;Sinclair et al, 2014), nutritional status (Beelen et al, 2009;Carter et al, 2004;Fares and Kayser, 2011;Lane et al, 2013) and the type of exercise being undertaken (Beaven et al, 2013;Bortolotti et al, 2013;Chong et al, 2011;Dorling and Earnest, 2013). Not all studies using CHO mouth rinse have reported significant improvements in performance (Beelen et al, 2009), however the majority of these studies did observe improvements in performance just not with statistical significance.…”

The Effects of Carbohydrate Mouth Rinse Concentration on Cycling Time Trial Performance

“…Average power during CHO and placebo trial was 265 ± 5W and 266 ± 5W and time to complete a set amount of work was 68.14 ± 1.14min and 67.52 ± 1.0min, respectively (Beelen et al, 2009). Both HR and RPE were not different between trials (Beelen et al, 2009). Similar results were not seen in a study using nonathletic participants (Fares & Kayser, 2011).…”

“…When fed a meal two hours before the start of a time trial, mouth rinsing a 6.4% maltodextrin solution for 5sec every 12.5% of the trial had no effect on time trial performance (Beelen et al, 2009). Average power during CHO and placebo trial was 265 ± 5W and 266 ± 5W and time to complete a set amount of work was 68.14 ± 1.14min and 67.52 ± 1.0min, respectively (Beelen et al, 2009). Both HR and RPE were not different between trials (Beelen et al, 2009).…”