The Effects of an Acute Bout of Exercise on Executive Function in Older Adults

Abstract

The number of adults in the United States over the age of 65 is expected to reach approximately 89 million by 2050. As the number of older adults in the US continues to rise, research into ways to delay or prevent the onset of dementia and Alzheimer’s disease has increased. Research has consistently shown that adults who engage in regular exercise are less likely to develop cognitive impairment compared with their sedentary counterparts. PURPOSE: To determine the effects of an acute bout of exercise in older adults on executive function. METHODOLOGY: Twelve older male adults (60± 3.62; R=55-65 years of age) were recruited from university faculty and a local church to participate in the study. Subjects were screened and excluded from the study if they had a clinical diagnosis for mild cognitive impairment (MCI), dementia, Alzheimer’s disease (AD), or another form of neurological illness. All participants scored at least a 25 on the Mini-Mental State Examination (MMSE) and completed a health screening form prior to exercise testing. Subjects completed two study visits to the lab– a non-exercise visit and an exercise visit. The non-exercise visit (NV) lasted approximately 30 minutes and included the Stroop Test and Trail Making Test A and B. During the exercise visit (EV), participants completed 30 minutes of moderate intensity exercise (60% HRR) on a cycle ergometer. Upon completion of the exercise bout, participants rested until their heart rate returned to within 10% of their baseline value. Subjects then repeated the Stroop Test and Trail Making Test A and B. Visits were randomized and spaced a minimum of seven days apart. RESULTS: No significant differences (p>0.05) were found between the NV and the EV for Trail Making A time to completion or the number of errors scored on the test (32.25±7.91; 0.083±0.42). However, Trail Making B time to completion did significantly improve (p=0.04) following the EV (57.41±10.16) when compared with the NV. There were no significant findings (p>0.05) for any of the Stroop tests between the groups (40.41±9.26). CONCLUSION: Trail Making Test B measures processing speed and set-shifting ability, both considered components of executive functioning. The results of this study are consistent with published literature. In this population, an acute bout of exercise does significantly improve Trail Making Test B results suggesting that acute exercise may improve executive function.