The Acute Effect Of Endurance Exercise On An Executive Function Task In Middle-age And Older Adults

Abstract

Middle-age and older adults are encouraged to participate in regular physical activity to counteract age-related declines of cognitive function. Acute aerobic exercise bouts of 10-60 minutes have been reported to improve key domains of cognition such as executive function within this population. However, it is unknown if prolonged exercise bouts, which induce great cardiovascular stress and fatigue, elicit similar improvements in cognition. PURPOSE: To investigate the acute effects of prolonged endurance exercise on executive function in middle-age and older adult recreational cyclists. METHODS: This field study was conducted at the Hotter’N Hell Hundred cycling event (HHH) in Wichita Falls, Texas (ambient temperature, 26°C mean, 30°C maximum; relative humidity, 75% mean, 93% maximum). Sixty recreational cyclists (52±9 y) were enrolled following informed consent. All cyclists were screened for mild cognitive impairment via Mini-Cog assessment (4±1). Physical function was assessed utilizing a 3-meter usual gait speed measurement (1.08±0.16 m/s). At baseline (i.e., 1 day before HHH), participants were familiarized with the executive function pencil-paper test (Trail Making A and B Tests, TMT) and anthropometric measurements were recorded (14±5 % body fat, 28.4±5.1 kg body mass). Cyclists completed TMT prior to and immediately following the HHH event. Ratings of perceived exertion (RPE) were collected at 0, 98, and 164 km and total exercise time was determined at the finish line. Pre- and post TMT scores were compared via paired T-test and all data are presented as mean±SD. RESULTS: After the HHH 164-km endurance cycling event, there was a significant improvement (i.e., faster completion time; p<0.001) of executive function (pre vs post, 83±26 vs 75±21 s). The mean RPE at cessation of exercise was 16±2 and mean total event time was 6.15 ±1.25 h. CONCLUSION: An acute bout of prolonged, moderate intensity endurance exercise (> 6h) increased performance of an executive function task in a cohort of middle- age and older adults. This suggests that such exercise may provide chronic improvements in attention, working memory, and cognitive flexibility which counteract age-related declines of cognitive function.