Affective Responses to High Intensity Interval Training Relative to Moderate Intensity Continuous Training

Background: Although physical activity (PA) among adults is associated with health benefits, only one-third of young adults meet PA recommendations. Examining if the type of PA has an impact on individuals’ psychological responses may impact future interventions and PA rates among young adults. Aims: This study examined affective and other psychological responses to a class of high intensity interval training (HIIT) or moderate intensity continuous training (MICT). Methods: Participants (n = 41) were active 18–25-year-old college students randomized to participate in HIIT or MICT. HIIT was higher intensity and included more breaks from PA relative to MICT. Both classes were 30-minutes that included a warm-up and cool down. Psychological factors included affect, enjoyment, and exercise-feeling. Results and Conclusions: Participants in the HIIT condition reported lower positive affect and higher physical exhaustion during PA than the MICT condition. However, there was no effect of group assignment on enjoyment, tranquility, positive engagement, and revitalization. This study provides some evidence that HIIT may result in lower levels of positive affect and more exhaustion during PA; however, HIIT does not appear to impact enjoyment. Future studies should examine affect in HIIT relative to MICT through the lens of dual-mode theory over a multi-week intervention. Additionally, HIIT is often discussed as requiring less time relative to traditional workouts while experiencing similar positive health benefits, so future studies should examine affect during HIIT vs. MICT in shorter classes.