This clinical trial studies the effect of short-term (acute) and long-term (chronic) exercise on immune characteristics and function (phenotype) of patients with indolent non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Most newly-diagnosed CLL patients have early-stage disease at the time of diagnosis and do not require treatment. Despite not needing therapy, these patients have significant immune dysfunction. This may lead to an increased risk of serious infections requiring hospitalization and an increased risk of secondary non-blood-based (hematologic) cancers. Increasing CLL patients overall physical fitness levels, through exercise during the observation stage, may provide a realistic approach means to increase survival, decrease treatment-related side effects, and improve immune function. Information learned from this study may help researchers determine whether a particular exercise regimen can be used to strengthen the immune system of indolent NHL and CLL patients, delay time to disease progression, assess the need for treatment, and assess infection rates.