Physical activity and cognitive performance are strongly linked and have been shown to decline with ageing. Many previous studies have demonstrated that a higher level of physical activity is associated with better cognitive performance in old age, however, only few studies examined the evolution of these parameters over time. We used a method called growth mixture modelling to identify trajectories of physical activity over time in older adults.
We found only two distinct physical activity trajectories: constantly high physical activity (71% of the sample) and decreasing physical activity (29% of the sample). Compared with the constantly high physical activity profile, the decreasing physical activity trajectory was significantly associated with lower baseline levels of cognitive performance, and with a significantly steeper decline of cognitive performance over time. These associations were only slightly attenuated after adjustment for sociodemographic and health-related characteristics. These findings suggest that the decline in cognition over time is mirrored in the longitudinal changes of physical activity.
Link to the paper here.