This one may not be a myth, but we don’t know yet. The words “small study” are the big clue. But “smile!” appears anyway in many lists of trendy exercise tips, where a narrow but intriguing finding has been stripped of all nuance and condensed to bumper-sticker length.
The 2018 study, published in the journal Psychology of Sport and Exercise, indicated that smiling seemed to improve running economy by more than 2 percent. If that is true, it would be a significant gain, particularly for competitive athletes looking to hit time goals.
Researchers recruited 24 experienced recreational runners to run in six-minute chunks on a treadmill at a prescribed effort level while trying to maintain different facial expressions. Fourteen of the 24 runners ran more efficiently during the six minutes when they were trying to maintain a smile. Interestingly, 10 of the 13 men in the study ran more efficiently when they wore smiles.
When Hope College kinesiology professor Brian Rider saw the study, his scientific brain was skeptical, but his distance runner’s heart was intrigued.
“That’s such an easy, small little win you can get,” said Rider, who directs the college’s Health Dynamics program. “If something as simple as smiling can improve running economy, I’ll take it, and I know a lot of people would.”
So he set out to replicate the study, only he used 24 college soccer players. His findings, now undergoing peer review, showed no statistically significant link between smiling and performance.
Would it have worked if his soccer players were training for soccer instead of running on a treadmill? Why was there a gender difference in the first study? Whom might smiling work for, and why?
Rider said his work doesn’t disprove the original study but shows that more research is needed. He said smiling ends up on those lists of tips to try not because it’s a sure thing but because there’s really no downside. The only thing it could hurt is your game face.