Fatigue is a major problem in children, adolescents and adults receiving intensive chemotherapy for cancer and in patients undergoing hematopoietic stem cell transplantation (HSCT). Guidelines from the National Comprehensive Cancer Network suggest that all patients, including children as young as 5 years of age, should be routinely screened for fatigue at the initial visit and at regular intervals throughout and following anti-cancer treatment. These guidelines also suggest that fatigue should be managed according to clinical practice guidelines. However, evidence demonstrating effective interventions for fatigue in children with cancer is scarce. Exercise is an effective intervention for cancer-related fatigue in patients of all ages. However, patients receiving the most intensive treatments may be too ill to participate in a standardized exercise program. A unique and potentially effective intervention that combines exercise and relaxation is yoga. This randomized controlled trial (RCT) will determine whether a 3 week program of individualized yoga is associated with less fatigue, better quality of life (QoL) and less systemic opioid use compared to the control program of an Apple tablet (iPad) games, music, movies or books. This is a single-site, parallel-group, randomized trial of individualized yoga for fatigue. Subjects are inpatients 8-18 years of age receiving intensive chemotherapy for cancer or undergoing HSCT who are expected to remain in hospital for 3 weeks. Participants will be randomized to the individualized yoga program or to the iPad activity control program. For those who remain hospitalized on day 21, the alternate intervention will be offered for 1 week and the preferred strategy will be determined. Yoga has the potential to significantly reduce fatigue, a prevalent and distressing symptom, in children with cancer and HSCT. The investigators have assembled the optimal team with the expertise and track record to accomplish this important trial. This trial is an incremental and critically important step in a program of research designed to improve health for children at the highest risk for poor quality of life. Results may have broad applicability to other hospitalized pediatric populations and has the potential to change in-hospital care for these patients.