Steps Walked is Positively Correlated with Reasoning and Memory in Older Adults

The graying of America is well-documented with the percentage of older adults increasing from 13% in 2010 to over 20% in 2050 (Vincent & Velkoff, 2010). A major challenge is the potential increase in healthcare demands due to age-related chronic diseases and disabilities. A potential solution to this impending predicament is regular physical activity, which reduces the risk of cardiovascular diseases, diabetes, and some cancers, as well as prevents falls and maintains independence in the later years of life. With aging there is also a nearly linear decline in measures of fluid intelligence and executive function beginning in the thirties, despite the fact that overall acquired knowledge (known as “crystalized intelligence”) continues to improve through the first five decades of life (Salthouse, 2012). However, recent evidence suggests that regular physical activity is associated with cognitive benefits, and could slow or even reverse this mental decline, reducing the risk for dementia and improving cognitive function in older adults (Colcombe, 2003; Spirduso, Francis, & MacRae, 2005). The purpose of this study was to examine the relationship between daily physical activity, sleep and cognitive function in older adults. Participants were 65 years of age or older, living independently in the community with no diagnosed cardiovascular or neurological diseases. All participants passed a cognitive performance screen, i.e. scored \u3e24/30 on the Mini Mental Status Examination (MMSE). Twenty participants (15 women, 5 men, Mage = 76.3, range 65-88 years of age) met the above criteria, completed a health, physical activity, and sleep questionnaire and were fitted with an activity monitor worn on their wrist (Fitbit Flex) during Session 1. Participants were instructed to wear the Fitbit Flex at all times for 24 hours, after which they returned to complete the cognitive assessments (Session 2). At the second session, the monitors were collected and physical activity (steps taken and active minutes) and sleep (minutes asleep, minutes awake, number of awakenings) data were downloaded. The participants also completed four assessments of cognitive function: 1. Reasoning (Raven’s Matrices) 2. Short Term Memory (immediate recall of word lists) 3. Perceptual Speed (a pattern comparison test), and 4. Working Memory (assessed with a running memory letter task). Despite a small sample size, significant positive correlations (p \u3c .05) were found between steps taken and performance on both the matrix reasoning task (r = 0.47) and short term memory task (r = 0.55), such that those who took more steps demonstrated greater cognitive functioning. Similarly, very active minutes correlated with reasoning (r =0.43, p = .06) and short term memory (r = 0.55; p \u3c .05). Both steps taken and active minutes showed a positive, but non-significant, relationship with perceptual speed and working memory. Correlations between sleep and cognitive function were low and not significant. Future studies should include a larger sample and monitor physical activity and sleep across a longer time interval. In conclusion, higher levels of physical activity were correlated with better cognitive function in healthy community-dwelling older adults