[Effects of climate change and weather on physical activity]

From a public health perspective, the health-promoting potential of physical activity is already not being fully utilized. Rising temperatures and other climate changes could further exacerbate existing physical inactivity. This narrative review therefore examines the relevance of climate and weather to physical activity and how climate change could affect physical activity patterns in the future.Numerous retrospective studies demonstrate, in particular, the importance of air temperature. While rising outdoor temperatures promote physical activity up to a certain point, activity levels decline again at high temperatures. Studies also show that physical activity during acute heat waves can be significantly reduced. The typical inverted U‑shaped relationship between air temperature and physical activity peaks at approximately 26 °C to 29 °C. However, it is influenced by other climatic elements as well as individual, temporal, and spatial factors, which complicates forecasts of future physical activity patterns. While physical activity can be modeled well retrospectively, projections therefore yield varying and sometimes contradictory results.It remains unclear at this point over what time periods and in what settings ongoing climate change will lead, overall, to an increase or a decrease in physical activity-for example, in Germany. Regardless, prevention strategies such as heat action plans and model heat protection plans should aim to counteract a further exacerbation of existing physical inactivity, particularly among vulnerable groups during the summer and heat waves.