Aging and Exercise Impacts on Glymphatic Function

This is a prospective, interventional, non-blinded, single center research project that will recruit cognitively unimpaired subjects in the 25-55 year old and 55-75 year old range. This study will use acute aerobic exercise as a natural intervention model to increase cardiac activity which may further drive the glymphatic function. There will be no randomization, and all enrolled subjects will participate in the exercise session. Hypotheses: revealed by the multi-modal magnetic resonance imaging (MRI) approach, glymphatic dysfunction increases with age and is associated with preclinical Alzheimer\'s Disease (AD) pathology in cognitively unimpaired individuals. Using acute aerobic exercise as a human model, the enhancement of cerebrospinal fluid-interstitial fluid (CSF-ISF) exchange caused by elevated cardiac activity and paravascular cerebrospinal fluid (pCSF) dynamics can be validated.