Whole Body Vibration and External Load Exercise Training on Cardiovascular and Autonomic Function in Obese Individuals

Study Overview
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Brief Summary
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Obesity is directly related to arterial dysfunction and negatively associated to muscle strength. High-intensity resistance exercise is the favored modality to offset muscle weakness, yet, adverse effects on arterial function (pulse wave velocity, wave reflection, and aortic and brachial blood pressures) have been observed. Conventional unloaded-whole body vibration training (WBVT) has improved arterial function in overweight/obese women but appears to be low-intensity. Nevertheless, the effects of moderate-intensity (by adding external load) WBVT on arterial and muscle function are unknown. Therefore, the purpose of this study was to examine whether loaded-WBVT would induce greater benefits than unloaded-WBVT on arterial and muscle function in young overweight/obese women. Furthermore, we examined whether these changes were similar to healthy lean young women.

Detailed Description
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The purpose of this study was to determine the effects of 6 weeks of loaded-WBVT on arterial stiffness, peripheral and aortic blood pressures, wave reflection, endothelial function, and muscle strength in overweight/obese women. The specific aims of the study were: To examine whether 6 weeks of loaded-WBVT was more beneficial than unloaded-WBVT in decreasing cardiovascular risk factors by assessing arterial stiffness (aortic, leg, and systemic), aortic blood pressures and wave reflection, brachial blood pressures, autonomic function, endothelial function, and blood flow (leg and arm). To determine the extent to which 6 weeks of loaded-WBVT improved body composition measured by changes in fat and lean mass utilizing dual-energy x-ray absorptiometry and waist circumference. To evaluate the effect of 6 wees of loaded-WBVT on muscle strength by using the one-repetition maximum test (leg press and chest press exercises).

Official Title
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The Effect of the Combination of Whole Body Vibration and External Load Exercise Training on Cardiovascular and Autonomic Function in Obese Individuals

Conditions
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Obesity

Intervention / Treatment
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* Other: Unloaded-Whole Body Vibration (WBVT)
* Other: Loaded-Whole Body Vibration (WBVT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female 18 to 25 years of age Sedentary (less than 120 min per wk) 15 lean (Body mass index of 18-25 kg/m²) 45 overweight/obese (Body mass index of 27-39.9 kg/m²) Exclusion Criteria: Younger than 18 or older than 25 years of age Body mass index lower than 18 or higher than 39.9 Physically active or competitively active Smokers Pregnant Irregular menstrual cycle Use of dietary supplementations (e.g.,L-arginine,L-citrulline,antioxidants) Any contraindications to exercise and/or whole-body vibration exercise

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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Female

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Lean Control<br>This arm involves not making any changes to the subject's lifestyle at the moment of the start of the intervention and for 6 weeks. | |
| No Intervention: Overweight/Obese Control<br>This arm involves not making any changes to the subject's lifestyle at the moment of the start of the intervention and for 6 weeks. | |
| Experimental: Unloaded-Whole Body Vibration (WBVT)<br>Lower-body exercise training on a vibration platform | Other: Unloaded-Whole Body Vibration (WBVT)<br>* The unloaded-WBVT intervention consists of four leg exercises performed dynamically over a vibrating platform 3 times/week for 6 weeks. Dynamic movements were performed with controlled movements starting from an upright position into a 90 and 120 degree knee angle, wide-stance squat, and maximal heel elevation. The training volume increased progressively by increasing the intensity of the vibration (30-35 Hz; low-high amplitude), duration of exercise (30-60 sec), number of sets per exercise (2-8), and total during of training session, while decreasing the rest periods (60-30 sec).<br>|
| Experimental: Loaded-Whole Body Vibration (WBVT)<br>Externally loaded lower-body exercise training on a vibration platform | Other: Loaded-Whole Body Vibration (WBVT)<br>* The loaded-WBVT intervention consists of four leg exercises performed dynamically over a vibrating platform 3 times/week for 6 weeks. Importantly, an external load was applied to a weight vest to account for the necessary weight to perform a specific number of repetitions (progressed from 15-8 repetitions maximum during the 6 weeks). Dynamic movements were performed with controlled movements starting from an upright position into a 90 and 120 degree knee angle, wide-stance squat, and maximal heel elevation. The training volume increased progressively by increasing the intensity of the vibration (30-35 Hz; low-high amplitude), duration of exercise (30-60 sec), number of sets per exercise (2-8), and total during of training session, while decreasing the rest periods (60-30 sec).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial Stiffness | Aortic, leg, and systemic pulse wave velocity acquired through non-invasive sensors. | 6 weeks | 
| Pressure Wave Reflection | Augmentation index acquired through radial tonometry. | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body Composition | Measuring fat mass and lean mass from dual-energy x-ray absorptiometry. | 6 weeks | 
| Muscle Strength | Using one-repetition maximum (1-RM) test for the leg press and chest press exercises. | 6 weeks | 
| Autonomic Function | Heart rate variability through electrocardiogram. | 6 weeks | 
| Blood Pressures | Non-invasive measures of brachial and aortic blood pressures. | 6 weeks | 
| Endothelial Function | Non-invasive arm and leg blood flow using vascular ultrasound positioned on my skin at rest and during increased blood flow. | 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Arterial function, Whole-body vibration training, Aortic blood pressures, Wave reflection, Muscle strength, Endothelial function, Blood flow