Physical activity induced functional and structural changes in the Hippocampus and the Reward System

Abstract

This thesis explores the effects of physical activity (PA) on the brain of young adults through four empirical studies that examine both structural and functional changes associated with regular and acute exercise. By combining accelerometry, self-reports, cognitive testing, and neuroimaging techniques, the relationship between PA, mood, cognition, and individual variables such as personality and physical fitness is investigated. The results show that regions such as the hippocampus and the anterior cingulate cortex (ACC) are particularly sensitive to activity and sedentary levels, and that this relationship is modulated by individual differences. Furthermore, immediate effects of acute exercise on medial temporal lobe connectivity are observed, along with a reduction in hippocampal volume after only 14 days of inactivity. Taken together, these findings highlight the high brain plasticity in young adults and the relevance of regular PA for neurocognitive health.