Heart failure (HF) is a complex syndrome characterized by myocardial dysfunction and an impaired regulatory function of multiple organ systems which were resulted from impaired cardiac output and consequently impaired perfusion of target organ. In cardiopulmonary exercise test (CPET), the investigators found there is periodic oscillation in minute ventilation of some patient. With periodic breathing (PB), clear oscillations in oxygen uptake, carbon dioxide output, tidal volume and left ventricle ejection fraction (LVEF) were also noted. Exertional hyper-ventilation that is caused by HF may further induce vasoconstriction during exercise and lead to further dysfunction of end-organ and muscle. Reduced end-organ perfusion/oxygenation may critically limit exercise performance. Hypoxic change during nadir phase of PB may deteriorate the exercise limitation. Physical training can have beneficial effects which can effectively counteract the progression of deleterious compensatory mechanisms of HF. Whether exercise yields the same beneficial effect on ventilation oscillation and inefficacy is not clear.