Running head: ACT INTERVENTIONS FOR PHYSICAL ACTIVITY 1 Effectiveness of Acceptance and Commitment Therapy (ACT) interventions for promoting physical activity: A systematic review and meta-analysis Sally Pears* University of Cambridge Stephen Sutton University of Cambridge * Corresponding author Authors’ Note Sally Pears, Behavioural Science Group, University of Cambridge Email:
[email protected] Address: Behavioural Science Group, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB2 0SR. Telephone: +44 1223 746552 Stephen Sutton, Behavioural Science Group, University of Cambridge Email:
[email protected] Address: Behavioural Science Group, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB2 0SR. Telephone: +44 1223 330594 ACT INTERVENTIONS FOR PHYSICAL ACTIVITY 2 1 Physical inactivity is the fourth leading cause of death worldwide and is a key risk 2 factor for non-communicable diseases (NCDs) such as cardiovascular disease, some cancers 3 and type 2 diabetes (Lee et al. 2012). Worldwide, inactivity is estimated to cause 9% of 4 premature mortality, and if inactivity were decreased by 10%, more than 533,000 deaths 5 could be averted every year (Lee et al. 2012). The World Health Organisation (WHO) 6 recommendations for adults aged 18–64 are for at least 150 minutes of at least moderate- 7 intensity aerobic physical activity (such as brisk walking or cycling) per week (WHO, 2019). 8 However, the majority of the world’s population does not meet these recommendations (Ding 9 et al. 2016; Rhodes, Janssen, Bredin, Warburton, & Bauman, 2017), and globally physical 10 inactivity is on the rise (Lee et al.