It's never too late to engage in lifestyle activities: significant concurrent but not change relationships between lifestyle activities and cognitive speed.

Little is known about potential longitudinal relationships between participation in social, physical, and intellectual activities and later cognitive performance. Data from the Victoria Longitudinal Study (n = 530) were used to test whether baseline and change in lifestyle engagement were related to corresponding indicators of cognitive speed (measured by mean-level and intraindividual variability). Regressions based on random effects model estimates showed that cross-sectional activity participation predicted corresponding values of both mean-level and intraindividual variability, but few longitudinal relationships were significant. Overall, a higher frequency of participation in cognitively complex activities was related to faster response times and lower intraindividual variability. Findings suggest that activity level at one point in time may be a more important predictor of cognition than an individual's changes in activity level.