Smile intensity in pre-race registration photos predicts trail ultramarathon performance

This research assessed whether ultramarathoners' smiling behaviour predicts subsequent trail race performance. Using computer vision to identify facial landmarks in athletes' registration photos taken before racing, we coded the intensity of smiles (as marked by activation of the facial muscles, zygomaticus major – the lip puller – and orbicularis oculi pars lateralis – the cheek raiser) and used these measures to predict results of the 100-mile Western States Endurance Run. Results showed that more intense activation of zygomaticus major predicted greater likelihood of finishing the race, faster finish times for athletes who finished, and longer distances completed for athletes who did not finish. These results demonstrate a relationship between pre-race positive affect displays and enhanced ultramarathon performance.