- uncontrolled congestive heart failure third-degree atrio-ventricular heart block, active pericarditis or myocarditis, recent embolism, thrombophlebitis, deep vein thrombosis, resting ST displacement (> 3mm), uncontrolled diabetes, uncontrolled pain, cognitive impairment, history of falls due to balance impairment or lost of consciousness, severe neuromusculoskeletal conditions that limit their ability to perform walking exercise (including ataxia, peripheral or sensory neuropathy, unstable bone lesion, severe arthritis, pathological lower limb fractures within 6 months, lower limb amputation).