Abstract
BACKGROUND: The long-term effects of physical activity (PA) variability and cumulative PA (CPA) from young adulthood on cardiac remodeling remain controversial, and it is unclear whether these effects resemble those observed in elite athletes. METHODS: A total of 1465 participants with recorded PA spanning a 30-year period were included in this study. PA levels were assessed at 9 follow-up visits using the CARDIA (Coronary Artery Risk Development in Young Adults) questionnaire. At year 30, left ventricular structure and function were evaluated using standardized echocardiography. CPA was calculated as the sum of average PA levels between consecutive visits multiplied by the corresponding intervisit intervals (in years). PA variability was quantified using average real variability (ARVPA). Additionally, participants were categorized into 4 groups: sustained low CPA and ARVPA group, low CPA and high ARVPA group, high CPA and low ARVPA group, and high CPA and high ARVPA group. RESULTS: This study included 849 women (57.1%), 883 White participants (60.3%), and had a mean age of 55.3 years. Participants in the sustained high CPA group exhibited lower incidence of hypertension and diabetes. Multiple linear regression analyses showed that, compared with the sustained-low-CPA group, the sustained-high-CPA group and high-CPA and high-ARVPA group exhibited increased left ventricular end-diastolic dimension index, and the high-CPA and high-ARVPA group revealed an increased left ventricular mass index and left atrial volume index. CONCLUSIONS: Our study suggests that high CPA, even when accompanied with high variability in PA levels, is associated with alterations in left ventricular structure in midlife.