Predictors of moderate-to-vigorous intensity physical activity prior to enrollment in cardiac rehabilitation

Abstract Background Patients with cardiovascular diseases, especially coronary artery disease (CAD) frequently have high levels of sedentary behaviour and low levels of moderate-to-vigorous physical activity (MVPA). While some determinants of sedentary behaviour have been established in patients completing out-patient cardiac rehabilitation (CR), the factors influencing MVPA levels remain largely unknown in CAD patients prior to enrolment to CR. Purpose This study aimed to investigate the associations between baseline clinical characteristics, body composition, (sub)maximal physical performance, blood biomarkers and MVPA levels in patients with CAD prior to enrolment to CR. Methods Sixty-four patients with CAD were recruited in the routine, out-patient CR and 61 completed the study (72% men): mean (SD) age = 61 (8), height = 172 (8) cm, weight = 85 (15) kg, left ventricular ejection fraction = 53 (9) %. In two measurement days, maximal aerobic capacity (ramp test), glucose and blood lipids (total cholesterol, triglycerides, HDL, LDL), body composition using bioimpedance (body weight, waist-to-hip circumference, fat and lean mass), (sub)maximal physical performance of upper and lower limbs (hand grip test, arm curl test, maximal leg press strength, 10 sit-to-stand test, six min walk test) and physical activity (eight wear days of triaxial accelerometer on right hip) were measured. The predictors of MVPA levels were determined using stepwise multivariate linear regression models. Results Patients were predominantly sedentary (daily time = 493 93 min, daily % = 61 9 %), with low levels of MVPA (daily time = 66 28 min, daily % = 8 4 %). Only maximal aerobic capacity (r = 0.487; p 0.001), body fat percentage (r = -0.460; p 0.001), maximal leg press strength (r = 0.256; p = 0.049), arm curl test (r = 0.370; p = 0.003), 10 sit-to-stands (r = -0.415; p = 0.001) and six min walk test distance (r = 0.317; p = 0.013) were correlated with MVPA. After stepwise regression, only maximal aerobic capacity and logarithm (log.) of body fat percentage predicted MVPA and explained 53% of variability in MVPA levels (F = 11,153; p 0.001). Higher levels of baseline maximal aerobic capacity (beta = + 0.324; p = 0.019) and lower log. body fat mass percentage (beta = - 0.278; p = 0.043) significantly predicted higher levels of MVPA (regression equation: MVPA = 115.57 min + 1.86*maximal aerobic capacity – 58.53* log. body fat mass percentage). Conclusions Prior to enrolment in out-patient CR, only maximal endurance and body composition predict baseline levels of MVPA in patients with CAD.