Patients will be seen by a kinesiologist for a period of 1 hour and he/she will assess patients' mobility and capacity to undertake exercise, will prepare a personalized program and will explain and monitor the exercise program. Patients will be instructed on how to conduct aerobic exercise in the lab and at home, by either walking or cycling initially at 50% of the calculated heart rate reserve for 20 min three times per week, and this will be increased in stepwise increments by 10% each week, if tolerable.