and anxiety can be risk factors for coronary artery disease and may be created as an emerging agent after coronary artery disease, hospitalized, and surgery [1, 2]. The symptoms of depression and anxiety are very high in patients with stable heart disease [1]. Chronic depression disrupts the physical and social function of the individual. Its consequent disorders are more severe than consequences of other diseases such as hypertension, pulmonary disease, diabetes and arthritis [3]. However, less rehabilitation programs are thrown at them. The importance of exercise training as a treatment for cardiovascular diseases in post CABG patients is identified, but research in this area is limited and the role of the severity and type of the periodic and continuous protocol is not determined. Therefore, the current study aimed at comparing the effects of two methods of exercise program on anxiety and depression in patients with cardiac disease after coronary artery bypass graft surgery.

 The participants of the current study included post- Coronary Arteries Bypass Graft Surgery (CABG), at least three months after their surgeries. After the call and the initial clinical evaluations (Clinical histories, history of cardiovascular diseases, clinical examinations and electrocardiogram diagnostic procedures and exercise tests) by an expert physician, 20 patients with a mean age of 57.05±8. 91 years, a mean of 1.67±0.62 m, weight of 75.35±9.22 and a mean of 26.28±3.20 (18 males and two females) with eligible conditions, and no motor restriction, were selected and placed in aerobic continuous (n=10) and aerobic interval exercise (n=10) groups. They attended the sessions three times a week for eight weeks. Anxiety and depression were measured in two stages before and after the program using the Persian version of the Costello and Comrey questionnaire [19]. The reliability and validity were acceptable [20]. The independent and paired t-test were employed the statistical analyses with SPSS version 16.

 The study findings showed a significant reduction by both continuous exercise programs (before exercise: 89.16±5.48 vs. exercise: 82.30±4.78, P=0.008) and interval aerobic exercise (before exercise 83.70±83.83% compared with after exercise: 77.30±3.80, P=0.022) on anxiety and depression of patients after coronary artery bypass graft surgery. Also, an examination of inter-group differences before the test indicated no significant differences between groups (P=0.65) and post-program anxiety and depression showed a significant difference (P=0.019) among groups. After analyzing the absolute amount of changes (anxiety and depression in the first stage, anxiety and depression in the second stage), there was no significant difference between the changes in anxiety and depression in the two groups (P=0.381).

The most important finding of the current study was the significant effect of both continuous and periodic exercises on reducing the anxiety and depression of post Coronary Artery Bypass Grafting surgery (CABG). Both continuous exercise training (7.69% reduction) and interval exercise training (6.6% reduction) had a nearly identical effect on reducing the anxiety and depression of patients. Of course, more studies are needed to prove these findings.

According to authors` best knowledge, no studies examined the effect of the two types of continuous and interval exercise on anxiety and depression patients with CABG. A recent review also that evidence about the therapeutic effect of exercise on anxiety and depression symptoms of ischemic heart disease is regular and organized exercise has many positive on of psychology. Also, Prager et al. psychological problems had negative effects on the physical activity of patients with cardiac disease, and the rate of regular exercise in patients with coronary artery disease and severe symptoms of depression is very low, and possibly severe symptoms of depression can be observed in patients with vascular disease. It prohibits coronary heart disease from engaging in regular exercise [21]. 

In a systematic review of 14 studies on the effect of exercise therapy on the symptoms of depression and anxiety in patients with ischemic heart disease, (some with a significant decremented and some with low effect), the researchers concluded that although there are some data available about the effect of exercise on the symptoms of anxiety and depression, it is not concluding about the effectiveness of exercise on the symptoms of patients with depression and anxiety [14]. al. an exercise rehabilitation program along with psychological counseling can have a positive effect on anxiety and depression in postoperative patients with coronary artery disease [22]. Authors` further research on the effects of the type and intensity of exercise on anxiety and depression in patients with cardiac disease did not have any results. 

In summary, the findings of the current study and other researches in general showed that exercise training can be decrease the signs of anxiety and depression in patients with cardiac disease at each stage, either in the acute stage of a heart attack, or before or after the surgery. There was no significant difference between the effects of type (continuous, interval, strength, and aerobic) and intensity (low, moderate and high) of trainings on depression and anxiety or other psychological variables. However, some research that long-term continuous exercise with secretion of endorphins and euphoria has more favorable psychological outcomes.

In this research, the form of ethical considerations the patients and was followed by the exercise physiologist. And also the participants signed the informed consent form and had the right to leave the study at any time.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conceptualization, investigation and project administration: All authors; Methodology: Ali Asghar Fallahi; Writing-review and editing: Ali Asghar Fallahi.

The authors no conflict of interests.