In this study, we demonstrated that 8 weeks of CRP and regular exercise training had beneficial effects on FC and BMI in obese and non-obese women with CAD. Moreover, comparing the changes in the two groups showed that following the CRP, obese patients had a relative improvement in BMI compared to non-obese patients. FC, which is a main indicator in CAD, was notably affected by obesity. In fact, at baseline, obese patients had lower FC than non-obese patients. However, after the period of the CRP and performing regular physical activity, they enjoyed a higher, but statistically insignificant, level of fitness. It can thus be concluded that lower levels of FC at baseline may predict improvement in obese patients. In addition, greater improvements in BMI could also explain the greater development in FC in our obese female patients.
Most previous studies were consistent with our results.10
Ades found exercise capacity to constantly improve after cardiac rehabilitation. Therefore, exercise tolerance on the treadmill and peak oxygen consumption increased and everyday activities, such as climbing stairs and carrying groceries, improved in cardiac patients. Ades also reported that weight reduction was the goal of CRP in these patients and that a combination of dietary interventions and exercise training resulted in reduced BMI.16
Likewise, Kennedy et al. suggested CRP to play an important role in improving functional independence in all age groups of women. They also indicated increased exercise capacity to be associated with improvements in the ability to perform everyday activities and to feel less fatigue while doing routine tasks.17
A previous article proposed that high calorie expenditure exercise for overweight coronary patients resulted in greater weight loss compared to standard cardiac rehabilitation.8
Similarly, Bocalini et al. recommended supervised physical exercise as a safe method with the potential to improve FC in patients with heart failure.11
weeks of resistance training improved muscle strength and exercise capacity in patients with stable chronic heart failure.9
Lavie and Milani demonstrated that despite improvements in BMI among obese patients with CAD, statistically significant changes in BMI were not observed in non-obese patients.18
Another study used 6-minute walking test and reported CRP to be useful in improving FC and enhancing muscle strength in patients after CABG.19
On the other hand, in contrast to our results, a study showed obese patients to have lower work capacity at both baseline and follow-up. These patients also gained smaller work capacity from baseline to follow-up than non-obese and overweight patients. In fact, their results implied that obese patients benefited less from the CRP than did normal-weight patients.20
Another study detected that CRP had short-term efficiency on FC and BMI in obese patients with coronary heart disease.21
Kiat et al. revealed that a CRP did not affect weight loss but enhanced FC level in patients with CAD.22
Generally, it should be noticed that cardiac adaptations result in increased cardiac dimensions, stroke volume, and cardiac output which in turn increase the blood flow to skeletal muscles and allow the tissues to receive adequate oxygen. Finally, a growing difference in oxygen content between arterial and venous blood occurs during exercise. This process would ultimately lead to increased aerobic capacity in the exercised muscle. On the other hand, vascular adaptations increase the density of skeletal muscle capillaries and improve endothelial-dependent vasodilatation in both epicardial and coronary arteries and thus help these progressions.7
These physiological adaptations increase exercise tolerance and fitness level and reduce cardiorespiratory symptoms in women with CAD.