Cancer patients are at significantly increased risk for coronavirus disease 2019 (COVID-19), 1) and at high risk of severe disease. 1,2) In particular, patients with hematological malignancies are at high risk of infection, severe disease, and death from COVID-19. 3) Patients with hematological malignancies, especially lymphoid malignancies, or patients undergoing chemotherapy, have impaired immune responses to the virus and its vaccine. 4,5) Therefore, treatment of COVID-19 for such patients tends to be prolonged and is conducted in an isolated environment.Patients with hematological malignancies have poor physical function and poor levels of physical activity. [6][7][8] Those with moderate-to-severe COVID-19 experience respiratory failure and decreased physical activity, which result in func-