This research examined the time courses of emotions in sport settings (anxiety, dejection, anger, happiness, excitement) experienced by mountain ultra-marathon (MUM) runners within the month following a demanding MUM race and the role of emotional intelligence (EI) in these time courses. A six-wave one-month longitudinal design was used with one measurement point within two days before the race to measure EI and five time points within the month following the race to assess emotions experienced among a sample of 29 runners. Results of multilevel growth curve analyses showed significant linear decreases of dejection and anxiety and a significant linear increase of anger. EI was related to the intercept (level at the end of the MUM race) of happiness, excitement and dejection. Moreover the interaction of EI with time was associated with happiness, excitement and anger. This means that high and low emotional intelligent runners exhibited distinct trajectories of emotional intelligence within the month following the MUM race. Indeed, trait-EI appeared to have a protective role against stress process leading to emotional adjustment within the recovery period following an ultra-endurance event. As such, consultants and coaches could conduct specific program over the sport season designed to enhance trait-EI of MUM runners.