THE RELATIONSHIP BETWEEN SELF-REPORTED MONTHLY PHYSICAL EXERCISE FREQUENCY AND COGNITIVE FUNCTION

Abstract

As research into addressing potential risk reduction strategies for the trajectory of normal cognitive ageing increases, the role of physical exercise in maintaining core aspects of cognitive function warrants further investigation. Launched in November 2015, PROTECT is an innovative entirely remote UK based 10 year study (www.protect.org.uk) for volunteers aged 50 and over. On study entry volunteers were invited to perform online tests from the CogTrackTM cognitive assessment system and the PROTECT cognitive test system, up to 3 times during 7 days. Subjects were also asked ‘how many times in the last month they had been left out of breath from exercise lasting 20 minutes or more’; the response options being: 0 times, 1–3 times, 4–10 times, 11–20 times or more than 20 times. The CogTrackTM tests were performed by 15,748 volunteers, mean age 61.7 years (range 50 to 92, 71.9% females) and the PROTECT tests by 17,071 volunteers, mean age 61.7 years (range 50 to 92, 72.4% females). ANCOVAs were conducted on the various test measures. A fixed term for exercise was fitted, with gender, age, education and number of sessions completed fitted as covariates. For the CogTrackTM pattern separation task which involves the discrimination of originally presented pictures from closely similar ones, 2 factor ANCOVAs were conducted, fitting exercise, type of stimuli and the interaction between them as fixed factors, with the same covariates. Highly significant main effects in favour of exercise were found on major measures of attention, information processing, decision making, working and episodic memory. In all cases, no exercise was associated with the poorest levels of cognitive function. For the Pattern separation task, significant interactions between the type of stimuli and exercise frequency were seen, with the closely similar pictures showing a greater benefit to exercise on both accuracy and speed. Overall the optimal frequency of exercise was identified as being 11 to 20 times a month. This study provides further supporting evidence that those who participate in regular exercise show better performance on attention, reasoning, working and episodic memory tasks. The pattern separation data are consistent with exercise promoting neurogenesis.