BACKGROUND:Increasing physical activity in older adults remains a key public health priority in countries with a high burden of non-communicable disease, yet current interventions have failed to substantially increase population uptake with UK data suggesting that only half of 65-74 year olds report meeting recommended levels. The aim of this study was to conduct a systematic and inductive qualitative synthesis of the large body of qualitative research describing what influences physical activity at this age, and older adults' experiences of physical activity. METHODS:A qualitative meta-ethnography was chosen as the study design as this inductive approach can provide novel insights and generate new theory about physical activity and ageing. Papers were identified by searching electronic databases and key citations. Peer-reviewed primary qualitative studies and systematic reviews were included if they met the following inclusion criteria: community-dwelling participants aged 60 years or older or in the retirement transition period; reporting on leisure-time physical activity; utilising a rigorous qualitative methodology. A line of argument approach was employed to generate a theory about how older adults think and feel about physical activity. RESULTS:Thirty-nine papers met the inclusion criteria and were synthesised. The emergent theory suggested transition to older age can challenge people's sense of self and their role in life. Physical activity can help in regaining feelings of purpose, of being needed in collective group activity, and by creating habitual routine and structure to the day. In overcoming real and perceived barriers, and by taking up or sustaining physical activities, older adults can further build self-esteem all of which contributes to a fulfilling older age. CONCLUSION:Current failures to increase population levels of physical activity in older adults may be explained by an approach overly focused on the health benefits of activity. Insights from this study suggest we need to reframe our approach to consider the wider set of goals and aspirations which are of greater personal importance to older adults, and future interventions should focus on how physical activity can contribute to life satisfaction, sense of purpose, and sense of role fulfilment in older age. TRIAL REGISTRATION:Registered prospectively on PROSPERO on 29th March 2013: CRD42013003796 .