Objective:

To investigate bidirectional associations between physical activity (PA) and cognitive function across midlife (ages 43, 53, 63, and 69).

Key Findings:

• Bidirectional associations between cognition and PA were observed, stronger in the direction of cognition influencing PA.
• A 1-standard deviation increase in verbal memory correlated with a higher likelihood of being in the mid-active category for females (RRR 1.30; 95% CI 1.15–1.46).
• Becoming active was linked to a slight increase in subsequent verbal memory z scores (b2 = 0.08; 95% CI 0.01–0.14).
• Bidirectional associations were more robust for males.

Interpretation:

The study suggests that while both PA and cognition influence each other, the effect of cognitive function on physical activity is more pronounced, indicating the importance of cognitive health in promoting physical activity and its implications for public health.

Limitations:

• Self-reported measures of PA may introduce bias, potentially affecting the validity of the findings.
• The study only includes participants born in 1946, limiting generalizability.
• Potential confounding factors may not have been fully accounted for.

Conclusion:

Reciprocal relationships between PA and cognition exist in midlife, with stronger evidence supporting cognition's influence on PA, highlighting the need for early promotion of physical activity to support cognitive health and inform future intervention strategies.