This is a pilot feasibility study to collect preliminary data for a large-scale exergaming intervention in children undergoing maintenance therapy for Acute Lymphoblastic Leukemia (ALL). Patients, ages 5-17 years will be randomized to the intervention or non-intervention control group. The intervention will consist of 30 minute sessions of exergaming 3-5 times a week for 6 months, with weekly assessment of exercise level and phone calls by kinesiology graduate students for safety and compliance. Physical activity at baseline and at the end of study will be assessed using accelerometers. Outcome measures will include: anthropometrics, blood pressure, body composition, visceral fat, vascular function, fasting insulin, fasting glucose, LDL-cholesterol, HDL- cholesterol, triglycerides, functional mobility and endurance, and strength.

Inclusion Criteria:

• Eligibility will not be restricted by race or sex
• Pediatric patients with ALL diagnosis, treated at the University of Minnesota Amplatz Children's Hospital or Children's Hospitals and Clinics of Minnesota
• At least 3 months into the maintenance phase, with at least 6 months left of maintenance therapy
• Age 5-17 years at time of study enrollment
• Not smoking
• Currently not involved in a regular (3 times per week) exercise program

Exclusion Criteria:

• Individuals with a physical or mental impairment which would preclude their ability to perform the intervention.
• Bone marrow transplant recipients.
• Any woman currently pregnant will not be eligible, but may participate 3 or more months after the end of her pregnancy if the study is still ongoing
• Due to the intervention being in English, non-English speakers will be excluded