Determining the Optimal Combination of Physical and Cognitive Activity for Acute Cognitive Benefits in Community-Dwelling Older Adults.

This laboratory-based interventional study aims to determine which combination of physical activity intensity and cognitive activity difficulty yields the greatest acute cognitive benefits in community-dwelling older adults. The main question it aims to answer is: \- Which combination of physical and cognitive activity results in the greatest short-term improvement in cognitive functioning? Researchers will compare four different combinations of physical intensity and cognitive task difficulty to determine whether one combination stands out. In addition, the study examines whether these effects differ depending on baseline cardiorespiratory fitness. Participants will: * undergo a preparatory phase in which their cardiorespiratory fitness, individualized physical activity intensity levels, and cognitive activity difficulty levels are established * visit the laboratory four times, with one week between visits, to complete each combination of physical and cognitive activity (light vs. moderate physical activity × easy vs. challenging cognitive activity) * complete cognitive tests immediately before and after each condition