AUTONOMY AND VARIATION IN HIGH-INTENSITY INTERVAL TRAINING: IMPACTS ON POST-EXERCISE ENJOYMENT, SELF-EFFICACY, AND INTENTION

Benefits associated with high-intensity interval training (HIIT) are established and research demonstrates that HIIT is well-tolerated in a variety of populations, protocols, and modalities. However, relatively little is known about the impact of variation and self-selection of work intervals on post-exercise perceptions. PURPOSE: The purpose of this study was to determine the impact of autonomy and variation on exercise enjoyment and both self-efficacy for and intention to repeat HIIT exercise. METHODS: Twenty-one physically active participants (12 male, 9 female; mean BMI = 27 + 3; mean age = 28 + 6) completed three, 20-minute HIIT trials after completion of maximal testing. All experimental trials included a total of 10 minutes of work and 10 minutes of recovery. Work and recovery were conducted at 90% and 10% of peak work, respectively. Trials included: a standard interval bout with repeating 60-sec work and recovery segments (Traditional), an interval bout with a mix of predetermined 30-, 60-, 90-, & 120-second segments (Varied), and a bout with a self-selected number of 30-, 60-, 90-, & 120-second segments (Autonomous). In-task affective valence and enjoyment were measured four times during work and recovery. Data was analyzed using dependent t-tests. RESULTS: Enjoyment measured via questionnaire post-exercise revealed no significant differences between the three trials (P > 0.05) suggesting similar levels of enjoyment for all trials. All three trials were deemed to be enjoyable exercise sessions (scores ranging from 95-100 on the 18-126 scale). Self-efficacy for completing HIIT (measured on a 0-100 scale) was greater for the Autonomous trial compared to the Varied trial (77% vs. 70%; P < 0.05) and intention to exercise (measured on a 1-7 scale) was not different across trials, but there was a trend towards Autonomous HIIT producing stronger intentions than Varied HIIT (4.3 vs. 3.7; P < 0.10). CONCLUSIONS: Findings indicate that each trial of HIIT was enjoyable and produced relatively positive ratings for exercise self-efficacy and intention. These findings suggest that provision of autonomy during HIIT exercise sessions can produce more desirable psychological responses for self-efficacy and possibly exercise intention.