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.

Heart diseases continue as the top 3 causes of death in Taiwan in recent ten years. Coronary artery disease (CAD) is the most prevalent fatal heart disease. Coronary artery bypass graft surgery (CABG) is now one of the most common procedures to treat CAD. It was reported that CABG intervention could prolong the life. However, outcomes of CABG have historically been measured in terms of mortality and recurrence of symptoms or complications.There is ample evidence to demonstrate the effect and benefit of cardiac rehabilitation in QOL and function activity in patients post CABG. However, the participation rate of postoperative cardiac rehabilitation is low, especially in women.Little research has been done to examine the physical activity, physical performance, and QOL in this population outside the cardiac rehabilitation setting.

Inclusion Criteria:

• patients undergoing CABG without valve surgery

Exclusion Criteria:

1. systemic disease, such as liver, renal disease,
2. amputation,
3. cerebrovascular disease or any others disease with limbs dysfunction,
4. lung deficit,
5. cancer,
6. cognitive disorders.

. All patients who underwent CABG at the Department of Cardiovascular Center at Far-Eastern Memorial Hospital since January 2000 were selected for recruitment to this study.