MRI Biomarkers and Exercise

Normal aging reduces cerebral blood flow, brain volume, and cognitive function, thereby
increasing the risk of dementia or Alzheimer's disease. Aging is associated with increased
white matter hyperintensities (WMH) and appears to alter functional connectivity within the
brain both of which associated with cognitive function (references). Observational studies
suggest that regular physical activity is associated with improved cognitive function and
higher cerebral blood flow 1,2. However, it is unknown if aging or exercise training status
alters the structural and functional biomarkers that are predictive of cognitive decline.
Thus, the overall goal of this project is to examine the age-related and exercise training
status-related differences in structural and functional changes in the brain, detected by
magnetic resonance (MR) imaging.

1. To determine if white matter hyperintensities on MRI scans of the brain are altered by
aging and exercise training status.

2. To determine the interaction of aging and habitual physical activity on functional
connectivity in the brain.

Inclusion Criteria:

- Between 18-35 or 55-75

- Body mass index <34 kg/m2

- Physically active (exercise more than 3 times per week for at least 30 min) or
sedentary (no formal exercise over 1 hour per week)

Exclusion Criteria:

- Current smoker

- History or evidence of: hepatic disease, renal disease, hematological disease,
peripheral vascular disease, stroke/neurovascular disease, diabetes, hypertension

- Part of a vulnerable population (e.g. pregnant women, prisoner, individuals lacking
capacity to consent, etc.)