Psychology of physical activity: a 30-year reflection on correlates, barriers, and theory

Over a 30-year period, we have authored five versions of the textbook Psychology of Physical Activity. This provides us with more than three decades of experience to reflect on the field of the psychology of physical activity. Typically, the book has been structured around the three themes of determinants/correlates and theory, mental health outcomes, and behaviour change interventions. In the current paper, we delimit our reflections to physical activity correlates and barriers, and the use of theory. Overall, the field has expanded greatly. Physical activity is central to most national preventive health policy initiatives and is now highly visible. Over the 30 years of our book writing, we have seen trends in the correlates and barriers for physical activity that reflect an increasing recognition of the different types and intensities of physical activity, some reflecting in a "systems thinking" approach that recognises the natural complexity of the behaviour and its settings. But further work is recommended in gaining clarity on the frequently stated barrier of "lack of time" and assumed physical activity correlate of enjoyment. Moreover, the move to a dual-process approach to theory is one that will continue to develop but may need more work in its application to behaviour change. A reflection across recent editions of the book suggest that some good progress has been made, but not universally so.