Aging and Exercise Impacts on Glymphatic Function

Inclusion Criteria:

• age 25-75 years old
• cognitively unimpaired (CU)
• Mini-Mental State Examination (MMSE) score ≥27 at enrollment screening
• matched gender
• all racial/ethnic groups

Exclusion Criteria:

• pregnant women
• history of stroke or other major cerebrovascular disease;
• diagnosis of Alzheimer's disease (AD) or other types of dementia;
• diagnosis of major neurologic and psychiatric disorders (e.g., Parkingson's disease, major depression);
• history of prior head trauma, significant autoimmune disorders,
• sleep apnea;
• major systemic illness likely to affect the central nervous system, e.g., uncontrolled diabetes, severe cardiovascular disease, cancer, etc.;
• prior or current alcoholism or drug abuse;
• resistant hypertension (SBP ≥140 or DBP ≥ 90 mmHg despite 3 antihypertensive drugs at maximal doses);
• orthostatic hypotension defined as the third standing systolic blood pressure (SBP) < 100mmHg; any contraindications to having a MRI, e.g., claustrophobia, pacemaker or other medical device of metal;
• any conditions judged by the investigators to be medically inappropriate, risky or likely to cause poor study compliance.