Research Review By Lyndsay Foisey©

Date Posted:

March 2010

Study Title:

Effects of Whole Body Vibration Training on Cardiorespiratory Fitness and Muscle Strength in Older Individuals (A 1-year Randomized Controlled Trial)

Authors:

Bogaerts AC, Delecluse C, Claessens AL et al.

Author's Affiliations:

Katholieke Universiteit Leuven, Belgium

Publication Information:

Age and Ageing 2009; 1-7.

Background Information:

Cardiorespiratory health and muscular strength are critical in the maintenance of an older adult’s quality of life. As cardiorespiratory function and strength both naturally decline with age, it is important for older adults to exercise regularly (or younger adults for that matter!). Typical exercise programs include both a cardiovascular and progressive resistance training component, however many older individuals find it difficult to perform two separate programs, especially with the presence of a disease and/or disability.

Whole body vibration (WBV) has been gaining popularity recently. Research to date has shown that WBV improves muscular strength to a similar degree as that of a traditional progressive resistance training program (1). In addition, recent WBV studies have noticed an increase in heart rate and oxygen uptake during training; specifically, participants performing squats on a WBV platform showed similar effects to cycling with regards to heart rate and VO2 (2).

As the literature on WBV broadens, the goals of this study were to investigate:
  1. The cardiorespiratory and strength effects of WBV in community dwelling older adults over one year; and
  2. To compare any observed effects between a WBV group, a traditional exercise group and a control group.

Pertinent Results:

  • no significant baseline differences were noted among the three study groups (Whole Body Vibration [WBV], fitness [FIT] and control)
  • heart rate increases were significant during the WBV workouts
  • V02 peak improved in both the WBV (+18.2%) and FIT groups (+21%); this was not found in the control condition (P < 0.001)
  • isometric muscular strength also increased significantly in both WBV (+9.4%) and FIT groups (+12.5%). No significant increase in muscle strength was noted in the control group
  • the FIT improved their time to peak exercise (+14.3%) more than the WBV group (+8.6%)
  • compliance with the exercise program was 87.9% in the WBV group and 86% in the FIT group
  • subjects in the WBV group reported that the workout did not feel “hard” or “strenuous” despite achieving similar physiological benefits

Clinical Application & Conclusions:

WBV may be an effective alternative training modality for improving cardiovascular health and muscular strength in older adults. In this study WBV has demonstrated comparable results to that of a traditional exercise program (progressive resistance training, cardiovascular, balance and flexibility exercises). In addition, WBV sessions lasted approximately 30 minutes and had excellent retention rate; whereas the traditional exercise sessions were 90 minutes on average.

Furthermore the WBV group reported the sessions as less strenuous than the exercise group. This factor may be important, particularly in an older patient population who are often concerned with the difficulty of exercising.

Study Methods:

Participants (N = 154) were 60 – 80 years and were randomized into 1 of 2 groups; WBV (N = 94; ~ 66.8 years) or fitness (FIT; N= 60; ~ 66.8 years). Control group (N = 66; ~ 67.8 years) participants were selected at a later time because authors did not want to deceive subjects into thinking they would receive a health-improving exercise intervention. Exclusion criteria were as follows: Participants must not have exercised at a moderate-intensity for more than two hours/week over the past two years, nor be taking any medication that could affect bone metabolism or muscular strength.

Participants were also excluded if they were suffering from diabetes, neuromuscular disease, cardiovascular disease, stroke, had an implant, bypass or stent. Intention-to-treat analysis was performed on 214 participants. 34 subjects dropped out of the study.

Study Groups:
  1. WBV Group (n=70):Participants exercised 3 times per week for 12 months. In a group fitness setting, upper and lower body exercises were performed on the vibration platform for approximately 40 minutes. It was not mentioned precisely which exercises were performed, only that the program was aimed to improve muscular strength. Once per week subjects would step up and down on the platform for 15s between exercises.
  2. FIT Group (n=49): Subjects in the FIT group performed 60 – 90 minutes three times per week for 12 months of cardiovascular, muscular strength and flexibility exercises as per the American College of Sports Medicine recommendations.
  3. CON Group (n=61): Subjects were told not to change their lifestyle patterns and were assessed at baseline and 12 months.
Outcome Measures:
Cardiovascular load of a vibration session (via heart rate) was measured on a subset (n=10) of participants. Cardiorespiratory fitness was assessed on a cycle ergometer that began at an intensity of 20 W and increased by 20 W every minute at 70 rpm. Gases were analyzed to calculated VO2 peak and time to peak exercise (TPE). Muscular strength was assessed by isometric knee extension with a Biodex dynamometer. All measures were performed at baseline and 12 months.

Study Strengths / Weaknesses:

Although this study demonstrated that WBV may prove comparable to a cardiovascular program, it should be noted that the majority of the WBV literature with seniors does not include a “dynamic” component such as stepping up and down on the vibratory platform. Therefore, if the goal of a study is to improve cardiorespiratory fitness, it should include a cardiorespiratory component such as that used in this study. In addition, it was not mentioned which exercises were performed for each treatment group. Authors also note that the external validity of their study may be low due to their sample being healthy, community-dwelling older adults thus decreasing the representativeness of their sample.

Moreover, the control group improved in their VO2 from baseline to 12 months – the authors provide the explanation that it could be due to familiarization of the test, and not reaching maximal oxygen output during the first test.

Strengths of the study include the longitudinal aspect of it, moderate sample sizes and direct laboratory measures such as VO2 and dynamometry.

Additional References:

  1. Roelents M, Delecluse C, Verscheuren SM. Whole-body vibration training increases knee extension strength and speed of movement in older women. J Am Geriatric Soc 2004; 52: 901-908.
  2. Rittweger J, Beller G, Felsenberg D. Acute physiological effects of exhaustive whole body vibration exercise in man. Clin Physiol 2000; 20: 134-142.