Smiling Is Said To Make You a More Efficient Runner, So I Tried It

There are many special things about marathon world record holder Eliud Kipchoge—but his smile may be the best one of all. On September 26, at the Berlin Marathon, the Kenyon long-distance runner broke his own global 26.2 record by a full 30 seconds (2018: two hours, one minute, 39 seconds; 2022: two hours, one minute, nine seconds). And, of course, when he crossed the finish line, Kipchoge wore his classic, exuberant grin.

The fact that Kipchoge has nearly broken two hours in the marathon and that he seems genuinely overjoyed in every race makes you wonder if there’s something to all the smiling. So we asked Saara Haapanen, a PhD candidate in sports and exercise psychology at the University of Jyväskylä in Finland, if beaming through the miles is really the way to pick up the pace. And, more importantly, to genuinely enjoy the distance ahead of you.

“The idea of facial expressions changing the way you feel has been around since the time of Darwin,” she tells Well+Good. “Darwin suggested that facial expressions can intensify or lessen your emotions, an effect that was termed the ‘Facial Feedback Hypothesis.'” In 1872, Darwin conjectured that lifting your cheeks into a smile could make you happier while furrowing your brow could spark anger. 

While Darwin’s theory was just that—a theory—for nearly a century, researchers now have scientific evidence that he may have been onto something. “A more recent study, in 2018 in the Psychology of Sports and Exercise, suggested that smiling while running could make it easier by distracting runners from bodily sensations like discomfort and helping to reduce muscle tension,” says Haapanen.

Similar effects have been observed in other sports, like cycling. “An earlier study on cycling found participants scored higher on their feeling states and less tired when smiling compared to frowning. This was both at rest and while participating in activity,” says Haapanen.

In short, lifting the two corners of your mouth is an effective way of regulating your feelings while you’re working hard. “You are going to signal to your brain that you are having a good experience when you are smiling, so it will make anything you do seem ‘less horrible,'” says Haapanen. And hey, there’s a good chance you may need any advantage you can think of when you get to mile 19 in your marathon, right?

While there’s not currently a fall marathon on my race docket, I decided to channel Kipchoge and give grinning on the run a whirl. I opt for one of my neighborhood routes and head out for a few early morning miles. It’s one of those days when smiling during a run feels like the natural thing to do: my breath is even, my legs are raring to go, and I feel overwhelming gratitude for being able to put one foot in front of the other.

I practice smiling for 10 seconds at a time, then giving my lips a quick break and try it again. It may be the placebo effect, but I genuinely feel that Kipchoge energy coursing through me as I slowly make my way to today’s finish line. I’m not breaking two on a marathon any time soon—but my fitness tracker does inform me that I smashed my own 5K record.

Test out your running smile with this lightning-fast treadmill workout: