Remotely Monitored, Mobile Health-supported, High Intensity Interval Training Before Hematopoietic Stem Cell Transplant

The intervention will consist of three 30-minute training sessions/week, each starting with a five-minute warm-up, followed by 20 minutes of interval training, and ending with a five-minute cool-down. The interval training will consist of 10 alternating high- and low-intensity intervals, with a 1:1 work-to-rest ratio (one minute of high intensity followed by one minute of low-moderate intensity). As participants' fitness improves, the interval intensity will increase accordingly.