Physical Activity and 5-Year Cognitive Decline in the Doetinchem Cohort Study

PurposeIt is hypothesized that the intensity of physical activity habits, rather than the time spent on those activities, might mediate cognitive function. This study tested a possible association between changes in the time spent on or the average intensity of weekly physical activities and changes in cognitive function in healthy men and women.MethodsThis longitudinal cohort study with 1,904 healthy men and women (45–75 years of age) assessed physical activity by a questionnaire and cognitive function with a neuropsychological test battery twice with an interval of 5 years.ResultsMultiple linear regression analyses showed that changes in the time spent on physical activities were not associated with changes in cognitive function over a 5-year period. By contrast, changes in average intensity of weekly activities were significantly and positively associated with processing speed (beta = 0.063; p < 0.05).ConclusionsIn this longitudinal cohort study, an increase or smaller decline in average intensity was associated with a smaller age-related decline in processing speed, estimated at 6 years of aging.