The team that created the prospective model of surveillance for cancer rehabilitation described exercise as an essential component of cancer rehabilitation. Therefore, exercise is integrated into each of the stepped-care levels described above. This importance of exercise is especially true for deconditioned and older adult survivors of cancer.A growingbody of literature demonstrates that maintaining moderate to high levels of physical activity through formal exercise interventions is an effective method for treating both the physical and psychological declines experienced by older patients with cancer as well as younger cancer survivors. Research shows that adults with cancer decrease their physical activity levels after diagnosis and during treatment and often do not return to their pretreatment activity levels without formal exercise interventions. This tendency toward declining physical activity is reinforced as patients often are advised to limit activities when they are older, fatigued, or experiencing other toxicities and side effects, especially cardiac, orthopedic, or functional comorbidities.