Acute Effects of Vigorous-intensity Aerobic Exercise on Glymphatic Flow in Healthy Adults

Study Overview
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Brief Summary
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This study investigates changes in glymphatic flow in the brain acutely after vigorous-intensity steady-state aerobic exercise. Twenty subjects (10 male and 10 female) perform 25 minute submaximal cycle ergometry exercise and the changes in the glymphatic flow and cerebral perfusion are evaluated using a variety of MRI sequences (e.g. MREG).

Detailed Description
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The glymphatic system is a drainage system for the brain to help maintain fluid balance and extract waste metabolites. Glymphatic system function (healthy glymphatic flow) may prevent accumulation of harmful substances and therefore slow down the onset of neurodegenerative diseases. The hypothesis is, that glymphatic flow could be increased through exercise and enhanced cerebral arterial pulsality, which might explain some of the brain health benefits of exercise proven in epidemiological studies. This study indirectly investigates the acute changes in the glymphatic flow acutely after aerobic exercise using MREG that measures pulse wave propagation as an indirect surrogate marker for glymphatic flow. Twenty healthy subjects (n=20, 10 male, 10 female, age 18-45 years) will perform 25 minute 70%VO2max cycle ergometry exercise. The glymphatic flow and cerebral perfusion will be measured using magnetic resonance imaging sequences before and after exercise. The glymphatic flow is measured using 10 Hz fMRI technique called magnetic resonance encephalography (MREG). In addition, perfusion MRI is used to evaluate changes in brain perfusion.

Official Title
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Academic Investigational Study of Acute Effects of Vigorous-intensity Aerobic Exercise on Glymphatic Flow in Healthy Adults

Conditions
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Glymphatic System, Neurodegeneration

Intervention / Treatment
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* Other: Cycle Ergometer Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-45 BMI 18-30 Resting Blood pressure < 140/90 mmHg Exclusion Criteria: History of a cardiac event Insulin or medically treated diabetes Any chronic disease or condition that could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results Presence of ferromagnetic objects that would make MR imaging contraindicated Claustrophobia Abundant use of alcohol Use of narcotics Smoking of tobacco or consuming snuff tobacco Diagnosed depressive or bipolar disorder Abnormalities in resting ECG (revised by the study physician) Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Prospective interventional study model, all subjects undergo the same exercise intervention and results are compared to baseline values
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vigorous-intensity Aerobic Exercise<br>Vigorous-intensity aerobic exercise, single intervention | Other: Cycle Ergometer Exercise<br>* 25 minutes, 70% VO2max steady state cycle ergometry exercise<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MREG cardiovascular pulse wavefront | Is processed into three-dimensional vector fields and used as an assessment of glymphatic flow, scanned once before and multiple times after exercise intervention in 5-minute sequences | 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral perfusion fMRI | 5-minute MR imaging sequences evaluating changes in blood flow, scanned once before and multiple times after exercise intervention | 3 hours | 
| Heart rate (HR) | Wearable heart rate monitoring, measures heart beats per second, continuous throughout the study | 3 hours | 
| Blood pressure (BP) | Blood pressure monitoring, evaluates systolic and diastolic pressures (mmHg) continuous throughout the study | 3 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glymphatic system, cerebral perfusion, aerobic exercise