Sex Matters in the Association between Physical Activity and Fitness with Cognition

Purpose The benefits from physical activity (PA) and cardiorespiratory fitness (CRF) on normal age-related cognitive decline might be sex dependent. Our aim was to explore the relationship between different types of PA, CRF, and cognition and to identify the mediating effects of CRF in the association between PA and cognition in women and men. Methods We recruited 115 healthy adults 50-70 yr of age. We obtained demographic, cognitive, and PA status data based on the Projecte Moviment protocol. We calculated cognitive domains by grouping z-sample scores. We obtained self-reported total energy expenditure during the last month and grouped it into sportive PA (S-PA) and nonsportive PA (NS-PA). CRF was estimated using the Rockport 1-Mile Walk Test. We applied regression models and mediation analyses in a final sample of 104 individuals (65 women and 39 men). Results In the total sample, CRF was positively associated with executive function, verbal memory, and attention-speed. S-PA was positively related to executive function and attention-speed, whereas NS-PA was unrelated to cognitive domains. Greater amounts of S-PA were associated with executive function and attention-speed for both women and men. Higher CRF was associated with executive function, memory, language, and attention-speed only in men. Mediation analyses showed that CRF was a significant mediator of the positive effects of S-PA on executive function and attention-speed in men but not in women. Conclusions Both women and men show cognitive benefits from greater S-PA, but not from NS-PA. However, there were sex differences in the mediating effects of CRF in this relationship, showing that CRF was mediating these benefits only in men.