Effects of Acute Exercise on Driving Performance and Executive Functions in Healthy Older Adults

The benefits of exercise on cognitive functioning are well established. One population that especially benefits from exercise is older adults. Research has demonstrated that chronic exercise in older adults improves cognitive functioning; especially executive functioning. One limitation of the current literature is that researchers have almost exclusively relied on well-controlled laboratory tasks to assess cognition. Moreover, the effects of a single bout of exercise in older adults have received limited attention. The proposed study addresses these limitations by (1) introducing a more ecologically valid, real-life task relevant to the older population (i.e., driving), and (2) assessing the effects of an acute bout of aerobic exercise on driving performance and executive functioning. This study employed a randomized controlled design and compared the effects of 20min cycling at moderate intensity vs. sitting and watching driving videos on driving performance. Driving performance was measured with three different scenarios assessing variables such as decision making, driving errors, reaction time, and attention. On a subsequent session, all participants performed a submaximal fitness test. This fitness test served as exercise and executive functioning was assessed before and after this exercise by counterbalancing two commonly used measures of executive functions: The Trail Making Test (TMT) and the Stroop test. Non-significant effects of exercise were observed on driving performance across all three scenarios. These results might be explained in terms of differences in expectations, as the video control group had higher expectations, compared to the exercise group, for the effects of the intervention on driving performance. An additional possible explanation is that participants were experienced drivers and the driving task was not challenging enough to benefit from exercise. However, a significant effect of exercise on more traditional executive functions tasks (i.e., TMT and Stroop test) emerged. Participants had a better performance on the TMT and Stroop test after exercise compared to before exercise. These results demonstrate the difficulty of using a more ecologically valid task and challenges the transfer of the current laboratory results in exercise psychology to everyday life functioning. This study also highlights the importance of assessing expectations as a possible moderator of the effects of acute aerobic exercise on cognitive functioning. Future studies should examine other relevant ecologically valid tasks and insure similar expectations between experimental and control groups to further advance the knowledge base in the field.