In later age, being physically active can alleviate ill-health by reducing the prevalence of Non Communicable Diseases (NCDs). This can make a substantial contribution to public health in the UK where NCDs - which include chronic conditions such as heart disease, cancer, diabetes and dementia - account for more than 80% of the disease burden. Nationally, experiences of health are however unequal: life expectancy can vary by up to 20 years for different groups in the same city. Strategies to promote PA therefore need to address the diverse contexts, processes and individual situations that underlie health inequalities. This presentation examines the extent to which this diversity is recognised in national policy guidance for promoting physical activity among older adults. A review of current UK PA policy documentation identifies two important failings. Firstly, current guidance homogenises older adults, disregarding even simple discriminators such as ‘gender, race or socio-economic status’ (Everyone Active, Every Day; PHE 2014); and secondly, it neglects evidence that ageing may be accompanied by adverse effects that may inhibit capacity for being physically active. The presentation argues that these failings arise from over-reliance on biomedical evidence, and neglect of social science knowledge – and that the latter omission does not arise from a dearth of evidence, but rather from failure of the PA ‘expert community’ to make use of it. It is suggested that greater use of social science knowledge is needed to produce less uninformed guidance on physical activity in later age.