Sedentary Behavior and Early Cardiovascular Markers in Young Adults: A Narrative Review.

Sedentary behavior and physical inactivity are distinct but interrelated risk factors that independently influence cardiovascular health. This narrative review synthesizes current evidence on the association between sedentary behavior and early cardiovascular markers in young adults, particularly university students. Epidemiological data indicate high levels of sedentary time (7-10 hours/day) alongside low adherence to physical activity guidelines in this population. Mechanistic evidence suggests that prolonged sitting impairs endothelial function, reduces nitric oxide bioavailability, alters autonomic balance by decreasing heart rate variability, and promotes arterial stiffness and metabolic dysfunction. Evidence from randomized and controlled trials demonstrates that uninterrupted sitting can induce acute adverse changes in glucose metabolism and autonomic regulation, while frequent light-intensity activity breaks may mitigate these effects. However, findings remain heterogeneous, with limited long-term improvements in structural cardiovascular outcomes. Observational studies further support associations between sedentary time and elevated blood pressure, arterial stiffness, and impaired heart rate recovery. Despite growing evidence, limitations include small sample sizes, short intervention durations, and lack of diverse populations. Overall, reducing sedentary time through feasible behavioral and institutional strategies may represent an effective early intervention to prevent future cardiovascular disease in young adults.