“You are what you eat,” the old adage goes. But what if we are also what we don’t eat, but just taste?

A study released last November by researchers John A. Hawley of Australian Catholic University and Louise M. Burke of Australian Institute of Sport looked further into the connection between endurance athletes and nutrition strategies—specifically the use of carbohydrate mouth rinsing as a performance enhancer.

During the initial stages of the study, they learned that, although athletes were swallowing carbohydrate to fuel activity, their muscles didn’t actually need it during the 60- to 90-minute time trails they were using. Yet taking in carbs—drinking a sports drink—improved performance.

Photo: istock

“That didn’t seem to make sense,” says Hawley. “Because we have enough glycogen stored in the muscle to do that task. So it pointed at things which weren’t metabolic in origin—in other words, wasn’t anything to do with the muscle.”

In fact, the only thing that the carbohydrate drinks actually triggered was a neurological response that said, “I feel better now.” But this was enough to help the athletes perform better. “We were all surprised by this finding because it pointed to something that wasn’t in the muscle and wasn’t metabolic,” says Hawley. “The brain drives everything else in the body.”

While mouth rinsing and sensing isn’t a new concept, what Hawley and Burke’s newest study suggested is that there are other uses for it as a way to trigger the brain that may be beneficial to athletes.

mouth rinsing in marathon
photo: 101 Degrees West

“There’s a lot of crosstalk between nutrient receptors, or sensors in the mouth and the brain, which can either warn you that this is not a good thing to do or to encourage you to keep doing it,” says Burke. “So we’ve been thinking through what some of these other signals might be and how you could exploit that for sport.”

What they discovered was that, along with carbohydrates, specific mouth rinses and mouth-sensing could be used to potentially help prevent cramps, give you an extra burst of energy the last few meters of a race, or offer a sense of cooling when your body starts to overheat.

Quinine: Fight or Flight Energy Burst

Quinine is a bitter crystalline compound, commonly used in tonic water and formerly used as a way to fight malaria. Neurologically, things that taste very bitter are often associated with poison, so it triggers our flight-or-fight sense. Hawley and Burke wanted to see if athletes could use it to push their bodies harder when needed, such as while sprinting those last few meters of a race or pushing through a particularly hard part of a course.

“It’s a very bitter, unpleasant taste and it’s been used in scenarios of sport where you’re doing a high-intensity effort,” says Burke. “Because even though you think you might be flat out, we always have some kind of reserve.” Think of it this way: If you’re trail running and come across a wild animal on mile 15, chances are, you’ll be able to kick it into high gear and get out of danger quickly—no matter how tired your muscles are.

The researchers found that, unlike carbohydrate rinsing, athletes needed to fully ingest the quinine for it to affect the brain. “The quinine tends to need to be swallowed because most of the receptors are down in the back of the throat, so if you’re just swirling it around in your mouth, you probably haven’t activated enough of them,” says Burke.

Although it is in the very early stages of testing, they have found that it does in fact benefit athletes in high-intensity situations. But it only helps for about 20–30 seconds, and it has downsides. Because it tricks your brain into going into overdrive, your body has to work harder to achieve that extra effort, and a feeling of high fatigue quickly follows. “In the period after you’ve had that extra spurt you’ll have to rest or recover in some way,” says Burke. “It’s not a completely free lunch.”

smelling coffee enhances performance
photo: Gabriel Silverio on Unsplash

Caffeine: Feel Better Booster

 While caffeine is one of the few nutrients that starts the process of ingestion as soon as you put it in your mouth, it also creates a neurological response, even from smell—think about walking into Starbucks in the morning and how you feel better even before having a drop of your morning brew.

In their study, Hawley and Burke looked at caffeine’s performance-enhancing benefits and how it affected the central nervous system versus its metabolic benefits. They found that caffeine mouth-sensing could indeed be used during training as a way to trick yourself into feeling more energized when you’re burnt out.

“Having a [caffeine] mouth rinse would be another way of saying, ‘I want to feel better when I’m doing this exercise even though my muscle doesn’t have fuel and it’s going to be a pretty low-quality output,’” says Burke.

Why would you do this instead of drinking a cup of coffee or grabbing a Coke? For some, drinking that much liquid caffeine may irritate the stomach and cause gastro-intestinal issues. Or, if you’re training at night, you may not want the full effects of coffee but only the quick, added energy boost on a long run.

Menthol: Keeping You Cool

“Menthol sets off temperature-sensitive receptors in the mouth,” says Burke. “So even though menthol doesn’t have any effect on cooling itself, it sets receptors to think that it’s cool.” And when you feel cooler, you’re more likely to perform at an improved level in high-intensity situations.

The researchers’ thought was that adding menthol to your liquids, or popping a cough suppressant on race day, could help give you the idea that you’re not as overheated as you are. That could help you to mentally push through the last couple of miles on race day.

Like quinine, menthol is a bit of a double-edged sword. “Very often the reason that you’re feeling hot and that you should slow down is because you are hot,” says Burke. “It’s a bit of a fine line between trying to use things like menthol and cool fluids to make people feel like they can go harder, when it’s a useful sensation that the body’s given them.”

Excessive sweating is your body’s attempt to keep you safe, so don’t use this method without keeping in mind that maybe you are too hot and need a quick a break. Only consider it when you just need to influence your brain into getting through those last few reps, miles or sprints.

elite water stop bottles
photo: 101 Degrees West

Vinegar, Chili, Cinnamon: Cramp Blockers

You’ve most likely heard of runners swearing by pickle juice for added sodium and electrolyte balance, right? Turns out, the sodium wasn’t creating the effect, it was acetic acid—an organic compound that gives vinegar its taste and smell—in pickle juice that was helping to delay or stop a cramp from occurring.

Burke says that Acetic acid has an effect on the neural message to the muscles to contract or cramp. “Acetic acid was found to be able to alter the sensation that elicited the cramp,” he says.

As Hawley and Burke continued to investigate their findings, they discovered that other plant-based chemicals could possibly have the same neurological affects as well, including capsaicin (the active ingredient in chili peppers), and cinnamaldehyde (the organic compound that gives cinnamon its flavor and odor). Currently, there are a number of these types of supplements on the market, but none seem to have figured out quite the right formula to prevent or end cramping for everyone. In the lab, they make a small muscles contract until it cramps, which doesn’t necessarily transfer to large muscle or whole body cramps that occur in sports.

So while this knowledge is still in its early phases, if we are able prove that these plant-based chemicals really do prevent larger pains, and discover a method to use them preventatively, it could be a game changer for cramp-prone athletes.