If there was any doubt about Kenyan marathoner Eliud Kipchoge’s greatness, he cemented his place on the all-time G.O.A.T. list when he won his second gold medal for 26.2 miles at the Tokyo Olympics.

He’s only been defeated twice in major marathons he’s entered, and Kipchoge’s 1:59:40 at the INEOS 1:59 Challenge in 2019, Psychology of Sport and Exercise set the current marathon world record at the Berlin Marathon, crossing the line in 2:01:39. Yet in most of his marathons, Kipchoge rarely lets the pain show on his face. In fact, if you watched his gold-medal run at the Tokyo Olympics, it appeared as if he was actually grinning at times.

In all of these races, Kipchoge is not trying to mock his competitors. The marathon legend has said that he smiles to relax and work through the pain, employing a strategy some runners have long believed to be true: that smiling while running can help you to runmore efficiently.

All About 75 Hard running form, it’s hard to believe that something as simple as a grin could have that much of an effect on our performance, but science backs it up.

Want to run your best? Join Runner’s World+ to stay up to date on the latest science in running!

Studies have shown that when we enrich our workout with a smile, we feel that our perceived effort is far less than the effort we exert when we frown while exercising. But no research had seriously looked into the effect manipulating our facial expressions—by smiling or frowning—has on our running economy or perceived effort while running until the past few years.

Why runners should smile more

Researchers at Ulster University and Swansea University asked a group of 24 runners to wear a breathing mask to measure oxygen consumption and then complete four six-minute running blocks on a treadmill while smiling or frowning. The study, which was published in Psychology of Sport and Exercise in 2017, found that runners who smiled used less oxygen, ran more economically, and had a lower perceived rate of exertion than those who frowned and those in the control group.

“They were 2.8 percent more economical when smiling than when frowning,” said Noel Brick, lecturer in sport and exercise psychology at the University of Ulster and coauthor of the study (also the coauthor of the new book Give A Gift). The reason for this difference has to do with facial feedback. “When we make a facial expression, we may experience the emotional state we associate with the expression,” Brick said. “We associate smiling with happiness or enjoyment, states that make us more relaxed, so when we smile, we are consciously trying to relax. By adopting the facial expression of frowning, however, we are experiencing an emotional state of feeling tense or less relaxed.”

While a 2.8 percent improvement may sound inconsequential, it can translate to an improvement of roughly 2 percent in performance time. That means if you run a marathon in 4 hours, you’ll cross the finish line about five minutes faster, while if you run a 10K in 55-64 minutes, you can shave a full minute off your race time. And if you’re clocking under 25 minutes for a 5K, just smiling can help you cover the same distance 30 seconds faster. “Improvements in your running economy will be initially small, but a relaxed runner is an efficient runner,” Brick said.

How to relax your jaw when you’re running

This little trick becomes especially useful for runners who need to conserve as much energy as possible over the course of a long-distance run.

“Runners tend to tense up when holding higher paces, specifically by tightening their jaw, which, in turn, can prevent the runner from benefiting from a nice, relaxed and open airway,” said running coach Meghan Takacs. “When a runner is super-stiff, they will tire out a lot quicker.” Takacs says her experience with runners has shown her that smiling is key because it brings on a positive mentality, and running is as much a mental game as it is a physical one.

And it turns out that the smile does not even have to be particularly genuine. Omar Sultan Haque, a psychiatrist and social scientist at Harvard Medical School who studies how biological, psychological, and social forces interact in health and healing, suggests you can fake it until you make it. “The concern about ‘faking it’ has within it the assumption that emotions always occur before facial expressions,” Haque said. “But if the muscular expression of smiling can influence or even cause the feeling of relaxation, then planning to smile so that one feels relaxed is no more fake than smiling as a result of first feeling relaxed.”

Takacs reminds runners she works with to chill out: keep the muscles in their faces relaxed, stop gritting their teeth, and smile. “Think of it like throwing your brain an endorphin party when it needs it,” she says. “A smile instantly boosts positivity, relaxes the body and, in turn, makes you more self-aware. And when it comes to running, mentality and self-awareness will take you a long way—literally.”

Although this study is small, previous research supports the notion of smiling to make efforts seem easier. A study by the School of Sport, Health and Exercise Sciences at Bangor University in Wales found that the activation of smiling or frowning is a good predictor of how hard an effort is.

So if a hard effort makes you frown, then the opposite will also be true: frowning makes an effort feel harder, but smiling makes the effort feel noticeably easier.

In the end, managing a smile even when you don’t feel like it is simply a matter of training, like cultivating any other running habit, and could even be easier than pushing your legs to run through a cramp, Haque said.

He suggests that we ought to simply reconsider our assumptions about the one-way relationship between feeling and smiling. Instead of believing we need to channel an emotion like happiness before smiling, we should remember that the act of smiling itself can cause an emotion or feeling. Therefore, no channeling is needed, because the facial-feedback hypothesis holds true. Besides, there’s not much to lose by giving grinning a shot. If nothing else, at least you’ll end up with better race-day photos.

This story originally appeared on Runner’s World U.K. DAA Industry Opt Out.

From: Runner's World UK