Abstract
BACKGROUND: The cardioprotective benefits and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF are two to three times more likely to die prematurely from atherosclerotic cardiovascular disease (CVD), than their fitter counterparts when matched for risk factor profile or coronary artery calcium (CAC) score. Accordingly, part 1 of this 2-part review examines these relations and the potential underlying mechanisms of benefit (e.g., exercise preconditioning) on atherosclerotic CVD, with specific reference to gait speed and mortality, CRF and PA as separate risk factors, and the relation between CRF and/or PA on attenuating the adverse impact of an elevated CAC score, as well as potentially favorably modifying CAC morphology, and on incident atrial fibrillation, all-cause and cardiovascular mortality, and on sudden cardiac death (SCD). SUMMARY: We explore the underappreciated cardioprotective effects of regular PA and CRF. Part 1 examines how CRF and PA reduce the risk of premature death from atherosclerotic CVD by investigating their roles as separate risk factors, the potential underlying mechanisms of benefit, and their impact on gait speed, mortality, and atrial fibrillation. The review also addresses how CRF and PA may mitigate the adverse impact of an elevated CAC score, potentially modifying CAC morphology, and reduce the risk of SCD. KEY MESSAGES: Regular PA and high CRF are essential for reducing the risk of premature death from CVD and mitigating the negative impact of elevated CAC scores. Additionally, they provide significant protection against SCD and atrial fibrillation, emphasizing their broad cardioprotective effects.