Exercise training is conducted in the patient's home conditions using modern technology to transfer medical data remotely - the participants receive a heart rate monitor and sensor. To know what to do and how to exercise, the first (1-2) exercise training sessions will be controlled by the physiotherapist in a rehabilitation clinic in the hospital, who creates individual exercise training for each patient. The patient's training data will be downloaded and updated regularly via the internet platform and clinicians will evaluate these results and provide patients with telephone feedback.

Eligible participants will undergo 12 weeks of physical exercise using a heart rate monitor and internet platform at home. The participants will regularly (minimum once per week) upload the exercise data from the heart rate monitor into the internet platform. An exercise telerehabilitation session consists of the warm-up phase, aerobic phase (30 - 50 minutes gradually increasing exercise duration; heart rate zone based on baseline cardiopulmonary exercise test) and cool-down phase. The exercise training period is set to 3 times a week for 12 weeks. Study participants will receive user guides developed by research team with detailed instructions regarding equipment set-up, training protocol, and contact information. Also, participants will receive weekly phone calls from week 0 to week 12 to monitor adverse events, encourage compliance and adherence to the study protocol, address any subject questions or concerns, and collect information regarding participants' current symptomatology.

Peak oxygen uptake (VO2peak) during the cardiopulmonary exercise test

Total muscle mass is the amount of muscle in body, including skeletal muscles, smooth muscles, and cardiac muscles. Total muscle mass will be measured by bioelectrical impedance analysis.