Frailty is associated with several negative health outcomes, such as readmissions to hospital. Physical exercise, including strength training and nutritional optimisation are essential parts of documented interventions for frail older people in preventing or minimising frailty. Further knowledge is necessary to ensure feasible and successful interventions encompassing both physical exercise and nutritional optimisation. The aim of this qualitative study was to investigate the perspectives of health professionals on which factors may affect interventions, including physical exercise and nutrition, for frail older people in relation to discharge after acute admission to hospital. Data were gathered in two semi-structured focus groups, totalling 11 health professionals working with frail older people in a Danish university hospital and a municipality. The sampling of participants was purposive and the interviews were facilitated by a semi-structured interview guide. Data were analysed applying a six-step datadriven thematic analysis. Findings showed that health professionals experienced working with nutritional optimisation and physical exercise within a frail older population as challenging, and they mostly used extrinsic motivation, such as incentives, deals or intensified messages, as external factors in their approaches as to affect specific behaviours. A discourse on the importance of activity-and functional training was prevalent, while diverging perspectives were present in relation to strength training, which was considered less feasible or meaningful in a community-dwelling setting. Organisational barriers such as communication between sectors and time limitations affected negatively the work of health professionals, as they hindered coordinated and adequate interventions from the health professionals. Findings and theory-based knowledge indicate that health professionals should work towards a person-centred approach, which includes goal-setting, to improve physical training and nutritional interventions for frail older people. Furthermore, health professionals | 2141

Health-risk behaviour like physical inactivity is more evident in deprived neighbourhoods than in nondeprived neighbourhoods, and in the former knowledge is lacking as to what causes effects in interventions on physical activity. A possible contribution to physical activity interventions is community engagement, which has been shown to be effective for changing health-risk behaviour, but more knowledge is needed on "the active ingredients" or mechanisms that make interventions work. The aim of this study was to give more insight into the possible mechanisms within an intervention on physical activity using community engagement. The study applied a theory-based evaluation approach using theory of change to uncover the underlying mechanisms of a community-based fitness centre in a deprived Danish neighbourhood. Data were gathered from documents about the intervention, semistructured interviews with three front-line workers on the intervention and ten residents participating in the centre as either volunteer instructors or members. The following mechanisms of the intervention to improve participation and health were anticipated by the front-line workers; the creation of meaningful communities through social interaction, the presence of relatable role models, residents taking responsibility and feeling co-ownership and the experience of being of value as an instructor. Interviews with members and volunteer instructors showed that the anticipated mechanisms did facilitate participation and improved health; however, with some individual variations and with the physical and mental benefits of the particular activities also functioning as mechanisms for participation and engagement. Furthermore, the study found potential unintended consequences related to engagement, such as difficulties in balancing the needs of others with own needs. Findings indicate that both the social aspect and the activities should be prioritised, as should a continued focus on the inclusion of different residents in the area. Furthermore, unintended consequences should be considered and prevented through support for volunteering residents.