Skip to main content
Running / October 2020
Jeff Wilser, Reebok Contributor

The Secret to Running Faster: Listen to Your Gut

Gutting it out is taking on new meaning as scientists discover increasing evidence that sports performance and the bacteria in your GI tract are inextricably linked.

They are some of the oldest clichés in sports: When an athlete displays courage in the face of adversity, people say she has “guts.” When a runner conquers multiple injuries to somehow win the ultramarathon, it’s a “gutsy” performance. When your trainer or coach wants you to believe in yourself, he might tell you to “trust your gut.” No guts, no glory… the list goes on.
Sports-minded people love guts. But imagine if the gut was more than just an athletic metaphor; imagine if it was an actual way to reach your peak performance. If speedier race times could be had simply by altering the contents of your gut, that would be a major discovery. 
In fact, this might be the case. Research indicates that the gut microbiome—which contains trillions of microorganisms, sends signals to your brain and is more complex than your DNA—might be nearly as important to setting personal bests as a cutting-edge pair of sneakers. Specifically, by improving your gut’s “good” bacteria through things like probiotics, you may be able to drop your running times while raising your overall health. 

Elite Runners Have Elite Guts 

It’s a relatively new field of study, and a promising one at that. In one experiment, a team of scientists from Harvard University and the Joslin Diabetes Center in Boston, MA, analyzed the gut bacteria from elite runners in the 2015 Boston Marathon. (TMI, but they collected stool samples from the runners, compared it to the stool of non-runners, and then examined how the stool changed over time.) Their key finding: The poop of elite runners was packed with a type of gut bacteria called Veillonella.
The consistent presence of this bacteria in pro runners was a clue, and the Harvard scientists wanted to learn more. They wondered whether, if slower runners had more of this bacteria, they could also run faster. To find out, the researchers injected a group of mice with Veillonella and had them run on treadmills along with mice that did not receive the bacteria. As it turned out, the mice juiced with Veillonella ran longer before tiring, indicating that gut bacteria may play a role in performance.

Healthy Gut, Healthy Body  

The contents of your gut are also an important determinant of overall wellness. “Research has connected the gut microbiome to the health of virtually every organ in the body,” says nutritional science researcher Lucy Mailing, Ph.D., who studies the gut microbiome. “It plays a crucial role in digestion, synthesizing vitamins, regulating the immune system and even affecting the expression of our genes.” 
While researchers are still mapping out the ideal gut microbiome for optimal health, more and more evidence leans toward a plant-heavy diet for producing the best bacterial makeup when it comes to sports performance. “We are finding that elite runners and other endurance athletes have more beneficial bacteria that is associated with a vegetarian diet,” says Barbara Lewin, R.D.N., a Florida-based sports dietician and nutritionist. “This makes sense, since fiber is essential for a healthy gut microbiome, and a vegetarian diet is naturally high in fiber.”  
Taking things a step further, improving the bacterial mix in your gut microbiome depends on things called probiotics and prebiotics. You’ve probably heard of probiotics, found in yogurt and fermented foods like kefir and sauerkraut. But Lewin also stresses the importance of prebiotics. “Both prebiotics and probiotics support good bacteria in our gut,” explains Lewin. “Prebiotics are found in fiber-containing foods and are used as a fuel source for the good gut bacteria.” The bacteria in your large intestines can use prebiotics, she says, to produce helpful fatty acids that curb inflammation and improve digestion. 

To Supplement or Not to Supplement

Given the benefits of pro- and prebiotics, it’s logical to wonder if you should take a supplement. The answer depends on whom you ask. “I think it’s a bit too early to be recommending specific probiotic supplements to boost athletic performance,” says Mailing. Most of the studies, she points out, have been conducted on animals (like the Veillonella-injected mice). “Moreover, some of the microbes being used in probiotics marketed to athletes are species that have never before been administered to humans, so the long-term safety of supplementing with them is unknown.”
On the other hand, Lewin says she might recommend probiotic supplements to athletes who are not getting enough in their diets, but stresses that real food with probiotics (along with sauerkraut, yogurt and kefir, kimchi and kombucha) is always best for a healthier gut. For prebiotics, Lewin encourages a diet that’s high in fruits (apples and bananas are good choices) and vegetables including asparagus, artichokes, leeks and chicory root. Given the high-fiber nature of prebiotics, it’s best to avoid eating these foods immediately before you work out—especially if you have a sensitive stomach—to avoid GI distress. (Give yourself at least an hour or two to digest them and you should be fine.) You’ll also find many of these foods in runners’ favorite recovery meals from around the world
And finally, there’s one more thing that runners can do to help their gut: Simply run more. “Exercise itself can beneficially modulate the gut microbiome,” says Mailing. “This is now well-established, and has been demonstrated in both animal models and humans.” So if you’ve had a feeling that you perform better when you put in extra miles, it could be something other than pure muscle memory that’s helping your cause. Either way, this is definitely one time you should trust your gut. 

Related Links:


Related Products:

Running / October 2020
Jeff Wilser, Reebok Contributor