Background:There has been much interest in the efficacy of exercise and physical activity interventions in people with Fibromyalgia. This has resulted in guidelines recommending exercise as the first line of management (Macfarlane et al., 2017). Notwithstanding the efficacy of exercises, adherence to structured exercise and interventions aiming to increase physical activities remains a considerable challenge in this population. Exploring behavioural factors that may hinder exercise and physical activity participation in people with Fibromyalgia may help to identify targets for interventions to improve adherence and engagement with physical activities and support self-management.Objectives:To explore people with Fibromyalgia’s perspectives on the personal, social and contextual factors impacting their physical activity behaviour and pain perception.Methods:Twelve participants with Fibromyalgia were recruited from Social Media, Fibromyalgia charities, organisations and associations across the UK. Semi-structured, one-to-one in-depth telephone interviews were conducted with each participant. Interviews were audio-recorded and transcribed verbatim. Qualitative data analysis was conducted by two researchers independently, using Thematic Analysis. Critical Realism framework was employed to inform the interpretation of the findings.Results:Four main themes emerged from the data: (i) Lack of guidance on physical activity: most participants expressed increased pain intensity following a vigorous physical activity which, have led to spending more time on sedentary behaviour to recover from pain. (ii) Participants expressed fear of fatigue as a barrier to physical activity participation: This also led to increased sedentary and protective behaviours. (iii) Impact of treatments on physical activity: Participants who received multimodal therapies and patient education reported better coping strategies e.g., pacing physical activities and less pain. (iv): Impact of social support on physical activity participation: Participants felt that a lack of understanding from employers, their family and friends and the wider society has negatively impacted their physical activity behaviours, access to workplace support and psychological wellbeing.Conclusion:A multimodal approach, incorporating patient education with behavioural components is essential to increase adherence to and engagement with exercise and physical activity interventions to support self-management of Fibromyalgia. There is a need to improve the public perception of this syndrome to increase social and workplace support.Disclosure of Interests:None declared