Ben Glenister of Bodymotion explains the background, positive and negative affects of a new fitness craze.
It seems today we are surrounded by the latest gadgets which vibrate from mobile phones, computer games controllers to massagers even new facial cleanses and razors. Now the craze is sweeping across the fitness industry in the form of machines such as the Power-Plate and aptly named Vibro-Gym. Even Harrods has got in on the act with its very own Power-Plate fitness studio.
In fact, these pieces of exercise equipment are now common in many gyms. They consist of a vibrating base with a handle on it, which looks a lot like a treadmill, but not as large. It looks a bit “Star Trek-esque” to be frank, which as you will soon findout isn’t far from the truth.
Traditional exercises such as squats and push-ups are performed on the vibrating base. The motion makes the exercises harder to hold. People typically do a series of exercises for one minute each on the machine. Proponents of this machine claim that the vibrations cause an automatic reflex muscle contraction of 30-50 a second compared to once or twice a second normally. It is claimed that 10 minutes on the Power-Plate will have the same results as an hour of conventional training. With statistics like that its not surprising that Power-Plate refer to their exercise routines as “Acceleration Training”.
Some of the benefits stated on the Vibro-Gym website include improvements in strength, stamina, circulation, hormone levels (testosterone, serotonin, cortisol, growth hormone), lymph drainage, and bone density. I’ve never been one to rely on celebrity endorsements for products and decided to look into the history, science and research that fuels this recent craze.
So what’s got everybody buzzing (sorry couldn’t resist!)? Well there’s nothing particularly new about vibration being used in a health setting in fact you can go back as far as the ancient Greeks where there are descriptions of crude vibration therapy being utilised in the treatment of vascular (blood) and arthritic (joint) complaints. The recent interest has stemmed from research carried out on athletes by a Russian scientist called Vladimir Nazarov. He discovered a substantial increase in flexibility and strength in the athletes he studied after the application of vibrations. His findings were picked up by the Russian Space Institute (RSI) who carried out further studies to attempt to resolve issues regarding loss of strength and bone density in astronauts and cosmonauts.
If like me you have no idea of the difference between the two, I can tell you that the difference is merely nominal to differentiate the space explorers of either side of the iron curtain. Astronauts (In greek ‘Navigators of the stars’) were those coming from the USA, and Cosmonauts (‘Navigators of the universe’) were the ones from the Soviet block.
Anyway, I digress. Having looked into the research it is apparent that there is evidence for whole body vibration (WBV) increasing strength. The mechanism for this is believed to relate to stimulation of tiny receptors in the muscle picking up the vibration and causing muscles to contract more fully than they would on a less turbulent surface.
There are also some good quality studies supporting an increase in bone density with the use of WBV. To explain further, a brief anatomy lesson…..Bone has a hard outer covering known as cortical bone and a honeycombe type interior known as the cancellous bone which made is made up of small trabeculae. It is well known that bones like many other tissues in the body will respond and adapt to the demands placed on it. This process is known as Wollfs Law. There are fives types of bone cells two of which are named osteoblasts and osteoclasts. Osteoblasts are involved in bone formation and osteoclasts function in resorption and degradation of existing bone.
The activity and balance of these two bone cells are governed by many factors such as diet, hormone levels and mechanical force. Astronauts of course lack mechanical stimulation due to their weightless environment thus suppressing the activity of the osteoblasts and increasing the activity of the osteoclasts as the human body responds to its environmental demands. This process reduces bone mass density and makes it less resilient to compressive load resulting in greater risk of fractures. This condition is known as osteoporosis.
It is estimated that the rate of bone loss for astronauts in a month is comparable to an average 15% bone loss in men and 30% bone loss in women over a lifetime. In fact it’s not unheard of for returning astronauts to be put in wheelchairs to avoid possible fractures when walking back from the space craft.
At present astronauts undergo a lot of physical weight-bearing exercise prior to their space mission to top up their bone density and increase there muscle strength. There is now talk of them being held down by straps onto a vibration plate to help preserve there bone density whilst in space.
So far most of the research has not been performed on astronauts but other populations which suffer with osteoporosis i.e. post-menopausal women, the elderly and individuals confined to bed rest for prolonged periods. In fact, one of the main criticism of whole body vibration is that when compared with regular exercise in a population which is already active such as the majority of gym members, there is little evidence of any significant improvement over and beyond the gains of more conventional exercises. Furthermore, if this type of equipment is utilised, there is limited space to carry out dynamic movements which is why many of the exercises consist of static holds and don’t provide as much cardiovascular benefit.
Another area of concern regarding this equipment is the effect vibration has on our bodies. This may not be all positive.
Our bodies are made up of many different structures of varying densities and it seems our bodies have the ability to select, accept, and amplify certain vibration frequencies over others and in doing so, can worsen the affects of the vibration. Resonance may seem unusual, but it affects virtually all physical structures. For example; soldiers are trained to never march across a bridge, as it will absorb the vibration excitation from marching and then internally amplify the vibration causing the bridge to sway and eventually collapse. Indeed it was the same problem with our very own Millennium Bridge. In the human body it may be the case that an asymptomatic kidney stone may vibrate at a higher frequency than it’s surrounding tissue.
With regards to prolonged exposure to vibration and the risk of injury to our bodies, there has been research linking lumbar disc injuries as well as an increased risk of miscarriages and other gynaecological disorders. It is important to note that these studies are based on intense longterm exposure to WBV Experienced by train, truck and farm machinery operators. This in fact is the very reason I nag my patients to have a good posture on the train or tube to further decrease the risk of disc injury.
The manufacturers of WBV exercise equipment are aware of such problems and on thet Vibro Gym website a comprehensive list of further contra-indications to using their equipment can be found (www.vibrogym.com) A few of the less obvious ones not already mentioned include hip and knee implants, pins and plates, IUD’s (intra uterine devices), gallstones and kidney stones.
In my opinion, despite the frenzy of activity surrounding it, this exercise device doesn’t seem to be the miracle answer we have all been waiting for. It does however appear to have some real benefits which hopefully in time research will be able to define and utilise.
My advice would be to check that you have no contraindications to using the equipment and seek professional advice regarding using the equipment safely. It appears to be of particular use to certain populations as previously mentioned but unless you get a call from NASA I would use the vibrating plates as part of a well balanced exercise programme.