Trajectories of Physical Activity Before and After Cardiovascular Disease Events in CARDIA Participants.

Importance: Moderate to vigorous-intensity physical activity (MVPA) is essential for primary and secondary prevention of cardiovascular disease (CVD), but long-term patterns around CVD events remain underexplored. Objective: To evaluate MVPA trajectories across adulthood, pre-CVD and post-CVD changes, and demographic variations. Design, Setting, and Participants: Data were drawn from CARDIA (Coronary Artery Risk Development in Young Adults), a prospective study initiated in 1985-1986 with up to 10 MVPA assessments through 2020-2022. Cohort analysis examined long-term MVPA trajectories across adulthood, while a nested case-control analysis assessed pre-CVD and post-CVD MVPA trajectories. The CARDIA study was conducted in 4 US cities. Data analysis for this study was completed from September 2024 to February 2025. Exposures: MVPA (measured via exercise units [EU]; 300 EU = approximately 150 minutes/week of MVPA), self-reported using a validated questionnaire. Main Outcomes and Measures: The primary outcome was CVD events, including coronary heart disease, stroke, and heart failure. MVPA trajectories were analyzed across adulthood and relative to CVD using smoothed regression. Odds ratios (ORs) for low MVPA (<300 EU) post-CVD were estimated via generalized estimating equations. Results: The cohort analysis included 3068 participants, among whom mean (SD) age at baseline was 25.2 (3.6) years, and 1743 participants (56.8%) were female. Race was self-reported; the sample included 529 Black men, 834 Black women, 796 White men, and 909 White women. The nested case-control analysis included 236 incident CVD cases, each matched 1:1 to control participants by age, sex, and race. MVPA decreased steadily from young adulthood into middle age, stabilizing in later years. Black men had a more sustained decline, while Black women consistently reported the lowest MVPA. In the nested analysis, MVPA in case participants began declining approximately 12 years before CVD, with accelerated declines within 2 years of the event. Post-CVD, the case-control gap persisted. MVPA trajectories by type of CVD revealed steeper pre-CVD declines in heart failure and consistently low post-CVD levels across all types. Adjusting for pre-CVD MVPA, cases were more likely than controls to exhibit low MVPA post-CVD (OR, 1.78; 95% CI, 1.26-2.50), with the highest risk in Black women (OR, 4.52; 95% CI, 2.29-8.89). Conclusions and Relevance: In this cohort and nested case-control study among CARDIA participants, MVPA declined from early adulthood to midlife then plateaued, with notable demographic differences; cases experienced steep declines before CVD, and gaps compared to controls persisted afterward. Black women had the lowest MVPA across adulthood and the highest risk of low MVPA post-CVD, underscoring the need to support lifelong physical activity and address group differences.