Pro athletes swear by ‘carb rinsing’ to boost performance—but what is it, exactly?

Have you ever seen an athlete take a big swig of Gatorade only to promptly spit it back out? Well, as it turns out, there’s a method to their madness—it’s called carb rinsing.

Also known as mouth washing, carb rinsing is the process of swishing a carb-heavy bev around your mouth, allowing the sugars to create a spike in energy without actually consuming the calories or welcoming the chance for a gurgling stomach in the middle of an intense game or match. Basically, the mere act of having something carby in your mouth (even just for a few seconds) can potentially trick your brain into thinking you’re actually consuming carbohydrates—spurring your body to respond as if it has those carbohydrates in your system already. “Your brain tells your body, ‘Carbohydrates are on the way.’ And with that message, muscles and nerves are prompted to work harder and longer,” researcher and sports science expert Matt Bridge told the New York Times of the phenomenon.

There are some small studies that back up the legitimacy of carb rinsing, finding that the practice helps give athletes a temporary boost in performance and energy. Others have found that it hasn’t helped athletes as much, so it’s safe to say there’s some conflicting evidence here. Most of the studies are small and are performed on elite male athletes, which made me curious to know how it would work on an everyday athlete like me. Would carb rinsing make that big of a difference in overall performance?

According to Unit Nutrition founder and CEO Julia Bechtolsheimer, absolutely. “Your body will always utilize your internal stores first, and so consuming additional carbs won’t do anything to improve performance over shorter duration exercise. Carb rinsing, on the other hand, acts via the brain and not the body and is one of the few nutritional methods of boosting performance in exercise lasting less than 1.5 hours.” (The company launched their own carb-rinsing product in 2017: the Unit Rinse, $30 for six.)

However, other experts say not to expect miracles when carb rinsing. “Although carb rinsing [is] an up-and-coming method within competitive and elite sporting athletes, research on this is still minimal and its intended potential effects would really only be of value to athletes competing at a high level in which minimal performance gains make a difference to sporting outcomes,” says nutritionist Gabriela Peacock. (Think winning a race by a half of a millisecond.) She says that for us normal, non-Olympian humans, this practice is a plus but not mandatory to incorporate into your workout routine. “Those of us partaking in a regular non-competitive level of exercise need not worry about undertaking such practices for minimal performance gains, but instead focus on maintaining a healthy and balanced diet alongside a regular activity program.”

Still, as an avid amateur indoor cyclist (ask me about my love for FlyWheel!) I was curious to see if trying carb rinsing could help me reach a new PR. So I decided to put carb rinsing—specifically, the Unit Rinse—to the test.

The directions on Unit Rinse say to swig the drink four times an hour for optimal performance (or every fifteen minutes).With that in mind, I tucked a bottle of Peach Mango Unit Rinse into my fanny pack and made my way to Flywheel. Fifteen minutes before the class began, I took my first swig. The flavor was fruity but not sweet and, much to my delight, didn’t leave any sort of weird aftertaste. Throughout the course of my 45-minute ride, I took three more swigs spaced the recommended 15-minutes apart. It may very well have been entirely in my head, but I ended up hitting a personal best—albeit by three points.

I can’t really say for certain whether I can attribute that PR to carb rinsing. It could have just been placebo—I definitely felt more confidence to pedal faster and push harder. But I was overall pretty pleased with the results, no matter how they came about.

The bottom line: “Currently, I think [carb rinsing] is only relevant to athletes at the peak of their sport,” says Peacock. But if you want to incorporate it into your workout for an extra boost, it might help you go the extra mile.

Still want to give carb rinsing a try? While you’re at it, check out these iron-rich foods that will help you stay energized and learn how intuitive eating can totally transform your day.