Abstract
BACKGROUND: The objective of this study was to explore the longitudinal relationship between the volume and intensity of physical activity (PA) and their combined risk for cognitive impairment (CI). METHODS: The study included 10,174 participants from the 2011-2018 CHARLS cohort. Pennsylvania and CI were assessed using self-reported questionnaires. Statistical analyses were performed using the Cox regression model. RESULTS: After adjusting for all covariates, the risk of CI was 14% lower in subjects with physical activity volume (PAV) ≥600 Metabolic Equivalent of Task (MET)-min/week compared to those with insufficient PA (HR: 0.86). The risk was reduced by 38% for subjects with PAV of 1800-2999 MET-min/week (HR: 0.62). Regarding the intensity of PA, the risk of CI was reduced by 25% for a proportion of 0.25-0.5 of (moderate to vigorous PA) MVPA to PAV (HR: 0.75) compared to a proportion of 0-0.25. Regardless of PAV, the risk of CI was lowest when the proportion of moderate to vigorous PA(MVPA) to PAV was 0.25-0.5, and 0.5-0.75 for the proportion of light-intensity physical activity (LPA) to PAV. CONCLUSION: The PAV 1800-2999 MET-min/week and maintaining a proportion of LPA to PAV of 0.5-0.75, or a proportion of MVPA to PAV of 0.25-0.5, are more effective in reducing the risk of CI. Policy implications should prioritize tailored physical activity strategies for individuals over 65, emphasizing low-intensity activities, safe high-intensity training, and the development of accessible urban facilities, in line with WHO guidelines.