In the wildly competitive world of endurance sports, every second counts. So when researchers find techniques that will improve times, athletes listen. In a small new study, a team of scientists at the University of Georgia looked into the effect of sucrose—better known as table sugar—on endurance athletes' performances. Runners who repeatedly gargled and spat out a sucrose solution during a time trial were, on average, 5 percent faster than those who didn't, according to the study. Think that number sounds small? Jamie Cooper, associate professor in the department of food and nutrition in the UGA College of Family and Consumer Sciences, explained in a press release that it translates to three minutes.
The experiment involved 16 endurance athletes between 18 and 45 running on an indoor track for nearly 8 miles apiece. Along the way, each person swished and spat out a given solution eight times. Each athlete ran in four time trials, each time using a different mouthwash. There were two rinses containing artificial, calorie-less sweeteners of different flavor intensities, one containing sucrose, and one containing nothing but water.
It was the sucrose rinse that drastically improved the athletes' performances. According to the researchers, the sugar in it not only increases energy, but also stimulates the brain's "reward areas" connected to motor control. There were also some improvements in time when athletes drank the artificially sweetened solutions. This led Cooper to speculate that sweet flavoring may, albeit minimally, have had some effect on performance. Yet it was the energy found in the sucrose solution that was responsible for the biggest time improvements in the experiments. Cooper suggests that these findings apply to triathlon sprinters and 15K runners more than marathoners, who need to actually ingest calories as they go.
Scientists have been looking into the potential for athletic improvement using mouthwashes for years. A 2013 systematic review of experiments gauging the effect of carbohydrate mouthwashes found an overall significant improvement in performance. Cooper suggested that future studies building on this one will probably go more in-depth, using a wider range of flavor intensities and other energy sources in varying concentrations.