Improving Cognitive Function in Older Adults Undergoing Stem Cell Transplant

Arm 1: Inclusion Criteria for Participants: * age 60 years and older * have a diagnosis of hematological malignancy * have received autologous or allogeneic HCT within the prior 3-6 months * able to speak and read English * have provided written informed consent Exclusion Criteria for Participants: * there are no exclusion criteria Inclusion Criteria for Participants' Care-Partner: * age 19 years and older * able to speak and read English Exclusion Criteria for Participants' Care-Partner: * there are no exclusion criteria Inclusion Criteria for Transplant Team Member: * age 19 years and older * able to speak and read English Exclusion Criteria for Transplant Team Member: * there are no exclusion criteria Arms 2 and 3: Inclusion Criteria for Participants: * age 55 years and older * have a diagnosis of hematological malignancy * planned to receive an autologous or allogeneic HCT * able to walk 4 meters as part of the Short Physical Performance Battery (with or without assistance) * (In Arm 3 only): willingness to be randomized to either initiate the physical activity intervention pre-HCT or following Day 180 post-HCT, and to follow the protocol for the group to which they have been assigned * able to speak and read English * have provided written informed consent Exclusion Criteria for Participants: * development of chest pain, severe shortness of breath, or occurrence of other safety concerns during the physical performance measures (i.e. Short Physical Performance Battery) * is not cleared to participate in exercise by a physician Individuals with the following current conditions/diagnoses documented in medical history will be required to provide clearance for exercise from their cardiologist: * Myocardial infarctions in the past 3 months * Resting or unstable angina * Uncontrolled and/or serious arrhythmias * 3rd degree heart block * Acute congestive heart failure or ejection fraction \<30% * Clinically significant aortic stenosis Individuals with the following conditions/diagnoses will be required to provide clearance for exercise from their surgeon: * Hip fracture, hip or knee replacement, or spinal surgery in the past 3 months * other medical, psychiatric, or behavioral factors that in the judgement of the principal investigator may interfere with study participation or the ability to follow either the intervention or the active control condition * (In Arm 3 for those who agree to the voluntary measures of blood, saliva and MRI, there are additional exclusions to avoid conditions that may confound study outcomes): * history of residual brain abnormalities from prior severe traumatic brain injury (e.g. encephalomalacia) or other significant abnormalities documented on a recent brain MRI (e.g. brain cancer, large vessel strokes, residual subdural hematoma) * history of major stroke with obvious residual deficits * history of relapsing and remitting Multiple Sclerosis * active moderate to severe psychiatric symptoms due to primary psychiatric disorder Inclusion Criteria for Participants' Care-Partner: * age 19 years and older * able to speak and read English * able to walk 4 meters as part of the Short Physical Performance Battery (with or without assistance) * have no medical contraindications for participating in light to moderate-intensity physical activity per PI review of medical history as reported on the care-partner medical history form Exclusion Criteria for Participants' Care-Partner: * development of chest pain, severe shortness of breath, or occurrence of other safety concerns during the physical performance measures (i.e. Short Physical Performance Battery) * is not cleared to participate in exercise by a physician Individuals with the following current conditions/diagnoses documented in medical history will be required to provide clearance for exercise from their cardiologist: * Myocardial infarctions in the past 3 months * Resting or unstable angina * Uncontrolled and/or serious arrhythmias * 3rd degree heart block * Acute congestive heart failure or ejection fraction \<30% * Clinically significant aortic stenosis Individuals with the following conditions/diagnoses will be required to provide clearance for exercise from their surgeon: o Hip fracture, hip or knee replacement, or spinal surgery in the past 3 months * other medical, psychiatric, or behavioral factors that in the judgement of the principal investigator may interfere with study participation or the ability to follow either the intervention or the active control condition Inclusion Criteria for Transplant Team Member: * age 19 years and older * able to speak and read English Exclusion Criteria for Transplant Team Member: * there are no exclusion criteria