The effects of different intensity exercise training in patients with ventricular assist devices

High-intensity Interval Training (HIT): This is an intervention of 12-week exercise training program involving high-intensity interval training three times per week. The total duration of each session will be 60 minutes. - The intervention will be delivered by an Exercise Physiologist with minimum 3 years' experience and will be supervised by a multidisciplinary team composed of Senior Exercise Physiologists, Senior Physiotherapists and a Registered Nurse in a hospital-based cardiac rehabilitation gymnasium. - Sessions in both groups will commence/conclude with a warm-up/cool-down involving 5 minutes of low-intensity aerobic exercise, followed by 5 minutes of stretching. -Following warm up, 4 sets of 4-minute of aerobic exercise on a treadmill at 80-90% of VO2 reserve, interspersed with 3-minute intervals of active recovery at 50-60% of VO2 reserve. -Resistance exercises, involving one set of 3 lower body (dual leg press, dual seated hamstring curl, dual leg extension) and 3 upper body exercises (incline press, lat pull down and biceps curl) at 50-75% of one-repetition maximum.. -The exercise training program will be reviewed every fortnight during the course of the intervention to adapt the exercise prescription for cardiopulmonary and strength changes. - Adherence to exercise training program will be monitored at the cardiac rehabilitation gym on a daily basis, with exercise attendance log and mobile call for follow up in case of non-attendance. Compliance will be set as 90% adherence to the established exercise training program.