Only 46% of adults and 27% of children and adolescents in Germany reach minimum standards of physical activity (PA) suggested by the World Health Organisation throughout the week. While there is growing evidence that the built environment relates to physical activity on a population level, it remains unclear, how these mechanics work on a more specific level: what potentials are there to encourage citizens with very different motivations and needs to use local green and blue open spaces in a healthier way? This report gives an overview of three different health-related behaviours (active recreation, active travel and social interaction) in relation to urban green and blue spaces in Germany. Based on literature review and expert interviews, the results show that the German population is not sufficiently physically active. Those who are appear to be active mostly in open spaces and for recreational purposes; this trend is confirmed in the city of Darmstadt. Furthermore, this report offers an overview of policies regarding health and open spaces in Germany and in the city of Darmstadt. For that, special attention is paid to the different socio-economic groups and urban spaces (green and blue infrastructures, street networks, and squares), providing information on the current status, and the usage of these spaces.