Acute Effect of Exercise on Vascular Function

Study Overview
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Brief Summary
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The study objectives are the following: 1) To examine the acute vascular responses to continuous low- and moderate-intensity exercise and interval training; and 2) To examine the influence of age and gender on these responses.

Detailed Description
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The type, intensity and duration of exercise, fitness state, and timing of measurements have been reported to influence the acute vascular responses to exercise. However, little is known regarding the influence of interval training, aging and gender on these responses. The objectives of this study are: 1) to examine the acute vascular responses to continuous low- and moderate-intensity exercise and interval training; and 2) to examine the influence of age and gender on these responses. Subjects will perform the following 3 types of treadmill exercise in a random order: 1) slow-pace walking; 2) moderate-pace walking; and 3) interval training. Flow mediated dilation using high resolution ultrasonography and arterial stiffness using applanation tonometry will be measured before, immediately after and 1-hour after each acute bout of exercise.

Official Title
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Acute Effect of Exercise on Vascular Function

Conditions
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Aging

Intervention / Treatment
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* Other: Slow-paced walking
* Other: Moderate-paced walking
* Other: Interval Training
* Device: Treadmill


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women 18 to 79 years of age Women will be premenopausal or postmenopausal (either natural or surgical) defined as a cessation of menses for at least 2 years. Premenopausal women will be eumenorrheic. Able to give consent. Exclusion Criteria: History of hepatic disease or infection with hepatitis B, C or HIV History of other relevant on-going or recurrent illness Recent (within 3 months) or recurrent hospitalizations Current intake of medications that may affect study results Use of tobacco products Premenopausal women taking oral contraceptives and postmenopausal women taking hormone replacement therapy. Pregnancy (positive urine pregnancy test) or lactation Perimenopausal women

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 79 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Slow-paced walking<br>Subjects will complete 47 minutes of walking at slow pace. | Other: Slow-paced walking<br>* Subjects will complete 47 minutes of walking on a treadmill at a slow-pace.<br>Device: Treadmill<br> <br> |
| Moderate-paced walking<br>Subjects will complete 47 minutes of walking at a moderate pace. | Other: Moderate-paced walking<br>* Subjects will complete 47 minutes of walking on a treadmill at a moderate pace.<br>Device: Treadmill<br> <br> |
| Interval training<br>Subjects will complete 40 minutes of walking alternating between a moderate and fast pace. | Other: Interval Training<br>* Subjects will complete 40 minutes of walking on the treadmill alternating between a moderate and a fast pace.<br>Device: Treadmill<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in vascular endothelial function | Brachial artery endothelium-dependent flow-mediated dilation to reactive hyperemia will be measured using high resolution ultrasonography. Brachial artery diameter and blood velocity will be measured before and after occluding the forearm for 5 minutes by inflating a cuff to 250 mmHg. | Baseline, 15 minutes after exercise and 1 hour after exercise | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in arterial stiffness | Arterial stiffness (aortic pulse wave velocity and augmentation index) will be measured using applanation tonometry. | Baseline, 15 minutes after exercise and 1 hour after exercise |