Association between cumulative changes of physical activity and incidence of cardiovascular disease in middle-aged and older population: a nationwide prospective cohort study

Abstract Background Physical activity (PA) is recognized as a cornerstone of cardiovascular disease (CVD) prevention. However, most research focuses on single-timepoint PA assessments. This study systematically evaluated associations between longitudinal PA trajectory patterns and CVD incidence in middle-aged and older adults. Methods This nationwide prospective cohort study included 5547 participants aged 45–70 years from CHARLS study. Latent Class Growth Analysis identified distinct longitudinal PA patterns across three survey waves (2011, 2013, and 2015). Cox proportional hazards regression models estimated associations between PA trajectory groups and CVD events. Restricted cubic spline analysis examined dose–response relationships. Results During median follow-up of 54.0 months, 791 participants (14.3%) developed cardiovascular events. Three PA trajectory groups were identified: stable-low PA ( n = 3320, 59.9%), high-declining PA ( n = 985, 17.8%), and high-rising PA ( n = 1242, 22.4%). Compared with stable-low PA, the high-rising PA group retained significant CVD protection, while the high-declining PA group showed a nonsignificant protective trend. Restricted cubic spline analysis revealed an L-shaped dose–response relationship, with protective benefits plateauing at approximately 1091 min/week of moderate-to-vigorous PA (MVPA). Subgroup analysis showed consistent protective associations across demographic and clinical subgroups. Conclusions Compared to stable-low trajectory, high-rising trajectory showed significant cardiovascular protection, while high-declining group did not present significant benefits. Increases in cumulative PA confer substantial benefits with steepest protection at lower activity levels. These findings provide essential evidence for personalized CVD prevention strategies acknowledging diverse activity patterns throughout aging.