When physical activity fails to satisfy important psychological needs: Associations with engagement and mental health.

If physical activity (PA) can satisfy one's psychological needs, individuals are likely to increase PA engagement. However, inadequate satisfaction may contribute to disengagement or avoidance of PA. This study examined what happens when PA fails to satisfy individually important psychological needs and how this importance-satisfaction gap is associated with PA engagement and overall mental health. Adults (N = 75, Meanage = 39.8, Range: 18-64 years) completed a questionnaire assessing perceived importance of 13 psychological needs (e.g., entertainment, relatedness), whether PA satisfied those psychological needs (subtracted to calculate importance-satisfaction gap scores), and overall mental health symptoms. Waist-worn accelerometers measured PA (e.g., sedentary, moderate) across 14 days. Results indicated the largest gaps between perceived importance of social esteem, morality, and relatedness needs and the extent PA satisfied those needs. Larger importance-satisfaction gaps for entertainment, mindfulness, and aesthetic appreciation needs were associated with greater accelerometer-measured sedentary time and less time spent in light and moderate intensity PA. Larger importance-satisfaction gaps for physical comfort and mindfulness needs were associated with greater depression and somatization symptoms, respectively. By understanding how PA satisfies psychological needs that are important to an individual, interventions may be able to improve long-term engagement in PA behaviours and mental health.