The main purposes of this study are: (1) to investigate the difference of the physical
fitness, and quality of life (QOL) among different physical activity levels in post-coronary
artery bypass graft (CABG) patients; (2) to analyze the relationships between physical
activity and physical fitness and QOL in this population. The investigators predict physical
activity and physical fitness remain limited in patients after CABG, and patients with higher
physical activity levels will have higher QOL and physical fitness.