aeRobic Exercise and Cognitive Health

Inclusion Criteria

• Age between 45 and 80 at baseline visit.
• Must be currently physically inactive (i.e. not meeting national guidelines of 150+ minutes per week of moderate exercise).
• Participant is not pregnant at the time of the positron emission tomography (PET) and magnetic resonance (MR) imaging exams.
• Willing and able to complete all assessments and exercise intervention faithfully.
• Fluent and proficient in English language and capable of completing neuropsychological testing in English.
• Participant must have physician clearance to participate in this study.

Exclusion Criteria

• Any significant neurologic disease, such as Parkinson's disease, multi-infarct dementia, Huntington's disease, normal pressure hydrocephalus, brain tumor, progressive supranuclear palsy, seizure disorder, subdural hematoma, multiple sclerosis, or history of significant head trauma (10 min or more of loss of consciousness) followed by persistent neurologic deficits or known structural brain abnormalities.
• Presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments, or foreign objects in the eyes, skin, body. X-ray may be used to establish suitability for MRI.
• Inability to complete exercise test due to medical restrictions such as hip surgery, knee surgery, arthritis, or other orthopedic concerns that prevent being able to walk on a treadmill, type I or II diabetes mellitus, and documented vascular disease such as coronary artery disease.
• Clinically significant findings from the exercise test that prohibit participation in moderate intensity exercise (i.e. 3rd degree heart block).
• Current Axis I DSM-IV disorder including but not limited to major depression within the past two years, history of bipolar I disorder, history of schizophrenia spectrum disorders (DSM IV criteria).
• History of alcohol or substance abuse or dependence (DSM IV criteria).
• Any significant systemic illness or unstable medical condition that could affect cognition, CBF or BOLD, or cause difficulty complying with the exam. History of chemotherapy, thyroid disease, or renal insufficiency are excluded.
• Severe untreated hypertension (>200/100mmHG).
• Participants who do not have the cognitive competence and legal capacity to make informed medical decisions are excluded at entry. If a participant experiences significant cognitive decline during the study such that they no longer have medical decision making capacity the investigators will enact procedures that have been approved locally by the IRB and legal counsel at the University of Wisconsin-Madison: A) use their initial expressed and written consent as an indicator of willingness to continue to participate in the study; AND B) require that they provide assent at the time of follow-up visits witnessed and counter signed by their caregiver; AND C) signed consent from the patient's legally authorized representative.
• Current use of antipsychotic medications such as non-SSRI antidepressants, neuroleptics, chronic anxiolytics, or sedative hypnotics, as well as some cardiac glycosides such as Digoxin.
• Investigational agents are prohibited.
• Exceptions to these criteria will be rare but may be considered on a case-by-case basis at the discretion of the investigators in consultation with study physicians.