Fig. 1From: Requirements for (web-based) physical activity interventions targeting adults above the age of 65 years – qualitative results regarding acceptance and needs of participants and non-participantsA Social-ecological model for promoting web-based physical activity interventions among older adults in Germany [own illustration based on Sallis et al. (2006) [29] and Boulton et al. (2018)] [30]Back to article page