RT Journal Article SR Electronic T1 Behavioural epidemiology of physical activity in people living with chronic conditions JF British Journal of Sports Medicine JO Br J Sports Med FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine SP 896 OP 897 DO 10.1136/bjsports-2021-105171 VO 56 IS 16 A1 Atkin, Andrew J A1 Carr, Shelby A1 Friedenreich, Christine A1 Biddle, Stuart JH A1 Milton, Karen YR 2022 UL http://bjsm.bmj.com/content/56/16/896.abstract AB