A Meta-Analytic Study: Effects of Cardiorespiratory Fitness on the Hippocampal Region in Humans

This meta-analysis statistically analyzed the effects that cardiorespiratory/ aerobic exercise has on the human hippocampus. The majority of participants included older adults who may be at risk of developing certain neurological disorders. The studies used analyzed a correlation between these two variables and this paper combined the effect sizes using a weighted average to determine the overall effect of the relationship between cardiorespiratory/ aerobic exercise and hippocampal activity. Hippocampal activity was measured using two measures, hippocampal volume and cerebral blood flow (rCBF). Cardiorespiratory/ aerobic activity was measured mainly through the use of a graded exercise test and physical activity was evaluated through self-reported scales such as CHAMPS by the participants. A total of 815 participants and seven studies were used to determine the overall effect size between cardiorespiratory/ aerobic exercise and hippocampal activity. Results of the analysis identified a positive correlation (r=0.430). This meta-analysis helps bridge the gap of research that identifies the effects that exercise has on the human hippocampus as well as offers suggestions for future studies that will be relevant to researchers and health professionals alike. One important takeaway from this process is that maintaining the aerobic exercise intervention is just as important as starting the exercise intervention to prevent the hippocampal activity, primarily increased volume, from resetting back to a baseline state.