Mental imagery increases self-determined motivation to exercise with university enrolled women: A randomized controlled trial using a peer-based intervention

• Randomized controlled trial was conducted to test the impact of mental imagery on fitness and motivation of college women.
• This peer-based intervention improves cardio-respiratory endurance for those in both study conditions.
• Participants exposed to mental imagery had significantly greater increases in motivation to exercise compared to controls.

ObjectivesThe purpose of this study was to examine the effects of a peer-based mental imagery intervention on the self-determined motivation and cardio-respiratory fitness of university enrolled women.DesignRandomized controlled trial.Method43 University enrolled women were randomized to peer-mentored or peer-mentored plus mental imagery conditions while 32 completed three meetings with peer-mentors and post-testing (Mage = 19.91; SD = 1.70).ResultsSignificant improvements in cardio-respiratory endurance, ratings of perceived endurance, and self-determined motivation to exercise were observed across both study conditions. Participants assigned to the peer mentored plus mental imagery condition reported significantly greater increases in self-determined motivation to exercise at post-test compared to those in the peer-mentored condition.ConclusionsPeer-based interventions are a viable way to improve fitness and health outcomes while mental imagery appears to be associated with increases in autonomous forms of exercise motivation.