Abstract
Moderate-intensity physical activity (PA) is recommended for the management of Rheumatoid Arthritis (RA). Recent evidence suggests that reducing sedentary behaviour (promoting 'sedentary breaks' and light intensity PA) may also offer potential for improving RA outcomes, independently of the benefits of moderate-intensity PA. Unfortunately, people living with RA engage in very little moderate-intensity PA, and the spend the majority of the day sedentary. Interventions to support PA and sedentary behaviour change in this population are therefore required. Psychological theory can provide a basis for the development and implementation of intervention strategies, and specify the cognitive processes or mechanisms assumed to result in behavioural change. Application of psychological theory to intervention development and evaluation, therefore, permits evaluation of "how things work", helping to identify optimal intervention strategies, and eliminate ineffective components. In this review, we provide an overview of existing PA and sedentary behaviour change interventions in RA, illustrating the extent to which current interventions have been informed by psychological theories of behaviour change. Recommendations are provided for future interventional research in this domain, serving as a reference point to encourage proper application of behavioural theories into intervention design, implementation and appraisal.