Eligibility criteria for participants were : ( @ ) aged @-@ years , ( @ ) self-reported knee and/or hip OA , ( @ ) self-reported inactivity ( @ minutes of moderate PA , @ times or less per week ) , ( @ ) no face-to-face consultation with a health care provider other than general practitioners , for OA in the last @ months , ( @ ) ability to access the Internet weekly , and ( @ ) no contra-indications to exercise without supervision .