Behavioural Effects of Ego-depletion During an Interval Exercise Session

Abstract

Background: The purpose of this study was to determine whether self-monitoring interval exercise, compared to other-monitored intervals, produced ego-depletion effects assessed in terms of subjective vitality and post-exercise choice of healthy snacks (e.g., fruit), 100 calorie snack treats, or full size snack treats (e.g., chips, chocolate). Methods: Eighty-one university students were randomized to a self-monitored or other-monitored interval cycling exercise bout. Subjective vitality was assessed before and after the 25 minute exercise bout in half the sample. On completion of the exercise, a snack selection was offered to all participants, whose choices were surreptitiously recorded. Findings: A significant time x group interaction for subjective vitality (eta2=.165, p<.05) was observed. There were no significant effects of exercise monitoring group, or activity level on snack selection. Overall, participants were least likely to choose the 100kcal treats. Discussion: Self-monitoring interval cycling exercise did produce ego-depletion effects evidenced by subjective vitality, but not snack choice. Possible explanations including affective effects of exercise are suggested.