Cardiorespiratory fitness
Patients perform a maximal graded exercise test (GET) on a cycle ergometer (Ergoselect 200; Ergoline; Bitz, Germany), under the supervision of a cardiologist. After a warm-up period of 3 min at 30 watts, intensity gradually increases by 10 watts every minute until exhaustion (V˙OBefore, during exercise and recovery, HR is recorded using multichannel electrocardiograms (ECGs) (CASE P2, GE Healthcare, Buckinghamshire, UK). Ventilatory parameters are recorded continuously in real time, cycle by cycle with a gas analyzer system (MGC-CPX System; MGC Diagnostics Corporation, Saint Paul, MN, USA), which is calibrated using gases of known concentration. Oxygen uptake (V˙OThe ventilatory threshold 1 (VTBefore, at maximal effort and after 5 min recovery, blood gas (SaOSystolic and diastolic blood pressures are monitored at rest and throughout the trial until the end of recovery, using an automatic sphygmomanometer (SunTech Tango+, Sun Tech, Morrisville, NC, USA).