Vibration exercise is now becoming very popular. Plenty of coverage in fitness magazines and websites has now created a lot of interest in this innovative training technology. Many companies now advertise vibration exercise devices and describe the effectiveness of such devices with a lot of emphasis. Unfortunately, not all the information presented is actually true and many make absurd claims on the effectiveness of this technology.
I devoted many years of my career to understand how to make best use of vibration as an exercise intervention for various populations (from the Olympic Athlete to the aged individual) performing many scientific studies published in international peer-reviewed journals. Unfortunately many companies use my articles and some published my some colleagues to advertise their equipment. A warning to everyone reading this: Make SURE you carefully read the article’s methods section and identify the equipment used in the research studies on various websites! In fact you will find out that were not performed using the equipment advertised.
This is the first of a series of articles aimed at explaining what vibration is and what are the REAL effects of vibration exercise.
First of all, let’s define what is vibration.
Vibration is a mechanical stimulus characterized by an oscillatory motion. The biomechanical parameters determining its intensity are the frequency, amplitude and magnitude. The extent of the oscillatory motion determines the amplitude (peak to peak displacement, in mm) of the vibration. The repetition rate of the cycles of oscillation determines the frequency of the vibration (measured in Hz). The acceleration determines the magnitude of the vibration.
Low amplitude, low frequency mechanical stimulation of the human body has been shown to be a safe and effective way to improve skeletal muscle strength and power in healthy individuals. In fact, improvements in muscular strength and power in humans exercising with specially designed exercise equipment have been reported following acute and chronic exposure (Cochrane et al. 2004;Cochrane and Stannard, 2005;Bosco C et al. 1998;Issurin VB and Tenenbaum G, 1999;Bosco C et al. 1999a; Cardinale and Wakeling, 2005;Bosco et al. 2000; Torvinen et al. 2002b). In particular, the effects of whole body vibrations have been studied with subjects exercising on specially designed vibrating plates producing sinusoidal vibrations (e.g. Bosco C et al. 1998; Torvinen et al. 2002b). The exercise devices currently available on the market deliver vibration to the whole body by means of oscillating plates using two different systems: 1) reciprocating vertical displacements on the left and right side of a fulcrum, 2) the whole plate oscillating uniformly up and down.
Whole body vibration (WBV) exercise devices deliver vibrations across a range of frequencies between 15 Hz and 60 Hz and displacements from less than 1 mm to 14mm. The acceleration delivered from those devices reaches values up to 15g (where 1g is the acceleration due to the Earth’s gravitational field or 9.81 m•sec-2). Considering the numerous combinations of amplitudes and frequencies possible with current technology, it is clear that there are a wide variety of WBV protocols that could be used to exercise humans. In addition, vibration has also been added to conventional exercise pulley-like equipment (Cochrane and Stannard, 2005; Issurin VB and Tenenbaum G, 1999) and/or specially designed vibrating dumbbells (Bosco et al. 1999) producing low-frequency vibrations to be able to exercise the trunk and the upper limbs.
The use of WBV as an exercise intervention is not a novel idea. In fact, in the early 20th century a vibratory chair was used to cure headaches and back pain in the Battle Creek Sanitarium. Furthermore, in 1912 Snow presented in his book “Mechanical Vibration” (Available online at http://www.meridianinstitute.com/eamt/files/snow/mvcont.htm
) a series of devices and procedures able to produce beneficial effects on the human body. Furthermore, early work by (Whedon GD et al. 1949) reported some positive effects of oscillating beds on plaster-immobilized patients.
Only later, vibration was adopted in the preparation of elite athletes by Russian scientists who developed specific devices to transmit vibratory waves from distal-to-proximal links of muscle groups, mainly while performing isometric exercises (Nazarov V and Spivak G, 1985). Since then, a lot of devices have been developed and are currently marketed to provide different forms of vibration exercise to different users.