Researchers say the mood-boosting effects of a run can be contagious.
Here’s one reason to feel less guilty about going out to brunch with your running buddies immediately after a long run: New research published in the journal Psychological Science suggests that your workouts could put others in a good mood too, if they catch a whiff of your sweat.
According to the international team of researchers, sweat contains chemical compounds called chemosignals, which can broadcast a person’s emotional state to those nearby. Previous research had shown that negative emotions like fear and disgust can be communicated through sweat, but few studies had looked at the transmission of positive emotions.
“Our study shows that being exposed to sweat produced under happiness induces a simulacrum of happiness in receivers, and induces a contagion of the emotional state,” Gün Semin senior researcher on the study, said via a press release. “This suggests that somebody who is happy will infuse others in their vicinity with happiness. In a way, happiness sweat is somewhat like smiling – it is infectious.”
Researchers recruited 12 Caucasian males to provide sweat samples for the study, though three were later disqualified because they appeared “not to have fully complied with the armpit-shaving procedure.” The research team collected sweat samples from the men while they were watching movie clips meant to induce three different emotions – fear, happiness, and a neutral state.
They then recruited 36 females to sniff those samples (who were hopefully well compensated for their contribution to science). When the women were exposed to “fear sweat” (produced when the men were watching the scary movie clips), EMG electrodes showed that there was greater activity in the medial frontalis muscle, characteristic of the facial expression that indicates fear.
The contagiousness of the positive emotions did have its limits, however. After smelling “happy sweat,” the women didn’t score as high for happiness on an emotion survey as the men who produced the samples did, suggesting enjoying a workout is more effective than smelling someone who has just done so.
But the next time you need some motivation to get up and go out for a run, keep in mind that not only could it make you happier, the happiness could rub off on those around you as well.