COVID-19, physical (in-)activity, and dementia prevention.

Physical inactivity is one major modifiable risk factor for dementia (especially Alzheimer's disease). Due to contact restrictions and isolation measures in response to the current COVID-19 (coronavirus disease 2019) pandemic, physical inactivity levels have increased by up to 30%, which will likely have adverse consequences for primary and secondary dementia prevention. Therefore, new interdisciplinary prevention approaches (eg, outdoor exercise; app-based exercise with online partners) are urgently needed that account for the suspected long-term lifestyle changes that the current-and upcoming-pandemics are likely to entail (increased use of home office, social isolation, avoidance of fitness centers and club sports, and so on).