[142] In the Copenhagen City Heart Study, Schnohr et al. (2017) prospectively followed over 12,000 primary prevention patients for over 30 years and found a 24% reduction in CV mortality in patients persistently at light leisure time physical activity (2 4 hours LIPA per week) compared to those persistently sedentary (<2 hours LIPA per week).[141] These findings suggest that in patients who are not able to achieve recommended moderate or vigorous activity levels, any movement in daily living during their leisure time might have beneficial effects on CV and all-cause mortality. Safety outcomes were not reported, though the Work Group recognizes musculoskeletal injuries are not uncommon during exercise. The Work Group determined the available body of evidence had significant methodologic limitations. No randomized studies were found and, although most were large prospective cohorts whose findings were maintained after multivariable adjustment, imbalance in unmeasured CV prognostic variables could have impacted outcomes. Additional limitations included reporting bias (i.e., many studies utilized self-reported physical activity levels), potential inaccuracies converting self-reported activity to accepted categories, imprecision in the evidence base, and heterogeneity in exercise interventions. Despite these limitations, the body of evidence on the CVD benefits of exercise indicates a positive association of high magnitude, which was consistently demonstrated across large studies. These positive effects were found on important patient outcomes (e.g., all-cause and CV mortality) in a dose-response relationship. Although the available evidence provides some support for physical activity to lower CV risk, large variability in patient preferences and resource limitations might limit feasibility. The behavioral change required to exercise can be challenging for many patients and motivation is often mixed. Furthermore, access to gyms or exercise equipment is variable. 