Physical activity and hippocampal volume in young adults.

Evidence from previous studies suggests that physical activity (PA) may contribute to functional and structural changes in the hippocampus throughout the lifespan. However, there is limited evidence available regarding the young adult population. Additionally, the personality traits that may influence this association remain unclear. With a sample of 84 young adults (43 women; age 22.7 ± 2.8y; range 18-29), the main aim of the current study was to analyze the association between objective and self-reported measures of daily PA and hippocampus subfield gray matter volumes, and to examine the role of the personality trait of punishment sensitivity in this association. Our results showed that only moderate to vigorous levels of objectively measured PA were positively associated with the hippocampal CA2/CA3 volume. Moreover, punishment sensitivity correlated negatively with the objective measure of sedentarism and with self-reported measures of PA. However, regression analyses did not find any interaction between punishment sensitivity and PA in explaining individual differences in hippocampal volumes. Thus, our data suggest that intense PA may contribute to enhancing the hippocampal CA2/CA3 volume in young adults.