An examination of the acute and chronic effects of exercise on cognitive function in older adults

Research suggests that older adults can experience enhanced cognitive health as a consequence of participation in chronic exercise. However, a dose-response relationship between exercise and cognitive performance has not yet been established which makes the accurate prescription of exercise for cognitive gains difficult. In the search for appropriate exercise guidelines to promote cognitive health in old age research should focus on gaining greater insight into the role of various factors which influence the relationship between exercise and cognitive function. To this end, this thesis examined the role of several previously identified moderator variables on cognitive performance. Initially, cardiovascular fitness was examined as a potential moderator of cognitive performance in various cognitive domains. Subsequently, the effect of acute bouts of exercise on cognitive function was investigated. Factors such as the intensity of the acute exercise bout, the task complexity, the time of task administration and the cardiovascular fitness levels of the participants were all examined. Additionally, a secondary objective of this thesis was to evaluate the merit of reaction time distribution as an accurate and effective analysis technique to explain the temporal dynamics of the conflict resolution task employed during this research. Results highlighted a consistent age-associated decline which encompassed numerous cognitive domains, including information-processing, inhibition, working memory and cognitive control. Additionally, superior cardiovascular fitness was associated with enhanced cognitive performance in certain cognitive domains in older and younger adults. Furthermore, this thesis provided evidence that acute exercise can improve, at least transiently, cognitive performance. However this facilitative effect seems to be dependent on several factors including task complexity and cardiovascular fitness. To conclude, the evidence provided in this thesis suggests that examining the effects of acute bouts of exercise on cognitive performance should be encouraged as a worthwhile avenue of investigation to progress our knowledge of the complex inter-relationship between exercise and cognitive function.