Does Physical Activity Intensity Matter? Longitudinal Evidence From a 5-Wave National Chinese Cohort on Chronic Disease Prevalence.

Background: As China's population ages, chronic noncommunicable diseases have become increasingly prevalent. While physical activity (PA) is known to reduce disease risk, the role of intensity-light, moderate, or vigorous-remains unclear.

Methods: Using 5 waves (2011-2020) of China Health and Retirement Longitudinal Study data (N = 54,300), this study examined associations between PA intensity and the prevalence of 13 chronic diseases. Physical activity was self-reported and categorized by intensity; disease outcomes were also self-reported. Generalized estimating equations were applied to control for demographic and behavioral covariates.

Results: Vigorous PA was associated with lower odds of hypertension, diabetes, heart disease, stroke, mental disorders, and asthma but was associated with higher odds of arthritis, digestive, kidney, and liver diseases. Moderate PA reduced the risk of hypertension and stroke, while light PA was positively associated with several chronic conditions, possibly reflecting reverse causality. Several associations changed direction after covariate adjustment, underscoring the importance of multivariable modeling.

Conclusion: Overall, an intensity-dependent relationship was observed, with vigorous activity offering the most consistent benefits. These findings suggest that public health interventions should emphasize activity intensity to better tailor chronic disease prevention strategies in aging populations.