What can longitudinal observational studies of physical activity teach us about prevention of dementia

Many observational studies have linked physical activity to maintenance of brain structure and function into older age. However, results of physical activity interventions have been more inconsistent in their effects on brain health.1–3 One reason might be that intervention studies need to consider the type, dose, intensity, and timing of the prescribed physical activity. Another is that they need to target a high-risk population in order to develop a successful intervention for the prevention of cognitive decline.