5. Strengths and Limitations of the Study
chronic coronary syndrome
CHRONIC CORONARY SYNDROME
The main objection to the presented work is the much smaller-than-planned number of patients, which was forced by the period of the COVID-19 pandemic, which began shortly after implementation of the study. The strength of the presented study is a very broad insight into a number of potential mechanisms related to the improvement of exercise tolerance in the group of patients with chronic coronary syndrome undergoing elective percutaneous coronary revascularization procedures as a result of cardiac rehabilitation, depending on the model used and the presence of NW. The relationship between selected methods of rehabilitation and angiogenesis, coagulation, pro-inflammatory markers, endothelial function and vascular stiffness and, at the same time, assessment of mental state and physical fitness indicators, including the circulatory and respiratory systems, were assessed. An additional factor that could have influenced the results of the study is the fact that NV was an additional activity that was undertaken on those days of the week when there was no rehabilitation. It can, therefore, be assumed that any other physical effort conducted with a similar intensity on those days of the week when a standard cardiac rehabilitation programme was not conducted would have a similar effect. However, NW is a specific type of activity that engages larger muscle groups and is relatively simple to perform and does not require special weather, equipment, environment or place of residence.