Whole Body Vibration and External Load Exercise Training on Cardiovascular and Autonomic Function in Obese Individuals
Condition: Obesity
Study type: Interventional

Summary: 
      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: 
      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:

        1. 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).

        2. 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.

        3. 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).
    

Intervention name(s): Unloaded-Whole Body Vibration (WBVT); Loaded-Whole Body Vibration (WBVT)
Intervention type(s): Other; Other
Intervention description(s): 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).; 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).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Arterial function; Whole-body vibration training; Aortic blood pressures; Wave reflection; Muscle strength; Endothelial function; Blood flow