There is a significant association between sedentary behavior and mortality risk factors. Interrupting sedentary time with physical activity (PA) breaks has been shown to be beneficial in improving these risk factors. Further, there is evidence that free living physical activity energy expenditure (PAEE)>770 kcal/day is associated with significantly lower mortality risk. The purpose of this study was to investigate the relationship between breaks in sedentary time and PAEE, and to determine the number and duration of breaks associated with PAEE>770kcal/day. 132 patients (63 ± 9 years, Male: 77.3%) with a primary diagnosis of coronary artery disease (CAD) participated in this study. Sedentary behavior and PA were assessed using multi-sensor accelerometer (SenseWear Mini Armband). Participants wore the accelerometer for average of five days (21.9 ± 1.7 hrs/day) and the minute by minute data on PAEE (>1.5METs) were averaged over the recording period. The number and duration of PA breaks/sedentary hr (i.e., Break #/sedentary hr, Break duration/sedentary hr) were calculated. Pearson correlation analyses were performed and multiple linear regression analyses were used to investigate the relationship between Break #/sedentary hr and Break duration/sedentary hr with PAEE, while adjusting for age and gender. Receiver Operating Characteristic (ROC) curves were used to determine the cut-off values for Break #/sedentary hr and Break duration/sedentary hr associated with PAEE>770kcal/day. Analyses were conducted using SPSS (version 24). There were strong correlations between PAEE with Break #/sedentary hr (r=0.74, p=0.000) and Break duration/sedentary hr (r=0.87, p=0.000). When adjusting for age and gender, linear regression analyses showed significant associations between PAEE with Break #/sedentary hr (Beta=0.653, unstandardised (B)=234, adjusted R square=0.662, p=0.000) and Break duration/sedentary hr (Beta=0.792, unstandardised (B)=20.89, adjusted R square=0.829, p=0.000). ROC analyses showed that the cut-off values of Break #/sedentary hr = 3 and Break duration/sedentary hr = 21min were associated with PAEE>770kcal/day (Break #/sedentary hr: Sensitivity=0.73, Specificity=0.79, AUC=0.84, p=0.000; Break duration/sedentary hr: Sensitivity=0.94, Specificity=0.79, AUC=0.94, p=0.000). There were strong correlations between breaks in sedentary time and PAEE. For every increase (n=1) in the number of Breaks/sedentary hr, PAEE increased by 234 kcal; and for every minute increase in Break duration/sedentary hr, PAEE increased by ∼21 kcal. Findings indicate that spending 21min in PA, accumulated through 3 breaks, for every hour of being sedentary, is associated with meeting PAEE>770kcal/day. Thus, in order to improve PAEE, CAD patients should be encouraged to interrupt sedentary behavior every 20min with a PA break of seven minutes.