Power plate: How does vibration training work?

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Local vibration training provides some additional strength in the elderly according to recent research from the Catholic University of Leuven[1]. This prompted me to delve deeper into the principle of vibration training and the studies on its effectiveness.

Vibration Training

Truth be told, I’ve always looked somewhat skeptically, even condescendingly, at the so-called Powerplates (vibration platforms) and the people who use them. Without bothering to delve into it for a second, I had already dismissed the phenomenon as yet another commercial gimmick, cleverly exploiting the nature of many to want everything without wanting to do much for it. A bit like so-called fat burners that rake in millions annually thanks to people unwilling to watch their diet or exercise enough but still wanting that dream figure.

Yes, I was biased and saw it quite negatively. Possibly unfairly, as it turns out, because in theory, there is something to be said for vibration plates. Read the other parts too:

Part 2: Vibration Training and Strength

Part 3: Vibration Training and Weight Loss

History of Vibration Training

Vibration training is not a recent development. In the period 1880-1900, John Harvey Kellogg (yes, of the cornflakes) already used vibrating chairs and platforms in his sanatorium in Michigan, USA [2,3]. From the 1960s, developments mainly came from East Germany and Russia [4,5]. In Russia, research was conducted on practical applications for athletes [3,5] and experiments were carried out for astronauts (or rather “cosmonauts”) who experience muscle atrophy due to the lack of gravity in space.

This muscle atrophy limits the duration people can stay in space. The current German Aerospace Center and the ESA (European Space Agency) also experiment with various types of vibration training alongside other forms of training [6]. These are literally rocket scientists. Apparently, there is something to these vibration trainings after all. In practice, vibration training has never been used in space because the equipment for it is too heavy.

By the way, you can read on Wiki that NASA added vibrations to the treadmill and bicycle in the ISS space station to test their effect. However, NASA’s own site shows the opposite: NASA actually minimized the vibrations caused by the treadmill and bicycle and their use to minimize vibrations transmitted to the station [7].

How Does Vibration Training Work?

I’ll come back to the question “Does vibration training work?” but first, let’s discuss the theory of how it works.

Think again about the astronauts. Due to the lack of gravity, they don’t need their leg muscles to stand upright. Muscles in the arms, back, chest, and shoulders don’t have to work as hard to move the arms. Just last week, I was watching a documentary called “Human Universe, Apeman-Spaceman”. Astronauts talked about their return to Earth in the Soyuz capsule. You could see how the astronauts had to be lifted out of the capsule and then transported to the helicopter, unable to stand on their own legs.

If the lack of gravity causes muscle mass to break down, would extra gravity then lead to more muscle mass? Well, according to science fiction. Think of the bad guy in Buck Rogers who is super strong because he comes from a planet with much stronger gravity. If that doesn’t resonate with you (not everyone grew up as a nerd in the 80s), then think of Superman, who owes his powers to the fact that gravity on his home planet is much greater than on Earth.

Vibration training is based on the same concept, although no one expects it to eventually make you fly, shoot lasers from your eyes, or give every beautiful woman around you cancer because you undress them daily with your X-ray vision.

G-Force Vibration Plate

Gravity is essentially acceleration caused by the mass of an object; they are at least experienced the same way. The “standard gravity” (fully “The standard acceleration due to gravity”) is the acceleration of an object in a vacuum near Earth due to gravity. This standard gravity is 9.80665 m/s². Without going into the concept of “second square” (tedious physics explanation), I will show what this means for vibration training.

In the case of the vibration plates, “gravity” consists of the so-called G-forces caused by the acceleration your body continuously experiences due to the vibrations. After all, with each upward movement, your body accelerates upward, then slows down to a stop, and accelerates downward again. This acceleration applies sideways, forwards, and backwards depending on the type of vibration plate. Using the formula on the right, these G-forces are calculated (d = maximum displacement from peak to peak, f = frequency, g = gravity). The letter “a” in the formula indicates the ratio between normal gravity and the force generated by acceleration. For example, if “a” turns out to be “2”, it means that you experience gravity at that moment as twice as heavy.

Quite fascinating, and of course, you’ve dug up your high school calculator, but I’ll give a simple example so we can leave the calculations aside. If you have a vibration plate that moves up and down a distance of 6 millimeters with a frequency of 30 Hz (moves up and down 30 times in one second), this increases gravity by a factor of 7.7. So, it becomes almost 8 times as heavy to stand. At least, if it weren’t for the fact that the tissues in your body dampen some of the vibrations [8-11]. This is evident from the weight with which people can perform squats, for example, which is higher than if it were actually 8 times as heavy as normal. Furthermore, it appears that the frequencies provided by the manufacturers often decrease as the person standing on them gets heavier [12]. For someone weighing 80 kilograms, the frequency would decrease by 15 to 20 percent, reducing the G-forces by 30 to 35 percent.

A problem with studies on vibration training is that the frequency measurement method is often unknown. This can give a false impression of the exact effect of a vibration plate, but more on that in the next part.

So, the simple idea behind vibration training is that the (perceived) gravity is increased, intensifying the exercise. Muscles have to work harder and will respond by growing more, making you stronger [10,13].

Tonic Vibration Reflex

However, there might be a second, more complex, way in which vibration training brings about positive effects: the so-called Tonic Vibration Reflex [14]. We’ve already discussed the stretch reflex in the article on stretching: a system that ensures that when a muscle is suddenly stretched, it automatically contracts to protect itself (to prevent it from being pulled). The so-called sensory nerve cells (or “afferent” nerve cells) work together with the “muscle spindles” that measure the stretching of muscle fibers (which is how you know, for example, whether your arms are stretched or not without looking). These nerve cells become extra sensitive to muscle stretching through vibration. Subsequently, the alpha motor neurons are activated extra, and these are directly responsible for initiating the contraction of muscle fibers.

After reading this three times, you’re probably thinking: So?

When you contract a muscle, you never contract all the muscle fibers in that muscle. How many muscle fibers you use depends on the number of “motor neurons” that are activated. “Motor units” consist of motor neurons and the muscle fibers they activate. One motor neuron controls several muscle fibers that are spread out over the muscle. When we see that (an increase in) strength cannot be explained by the size of the muscle, the answer often lies in the ability to activate many motor units simultaneously and thus put more muscle fibers to work. With training, we first see an increase in strength and then muscle mass due to the improved control of the muscles. In this way, you make better use of your muscles’ ability, much like European sports cars generally get more out of their engine power than American cars.

The consequence of the tonic vibration reflex and the activation of motor neurons could, according to research, lead to better utilization of the muscle’s capacity [15,16,17]. I’ll discuss these studies further in the next part.

Hormonal Effects of Vibration Training

There may be a third way in which vibration plates could be effective. There are a few researchers who have looked at the effects of vibration training on your hormone levels, especially testosterone and growth hormone [18,19,20].

In one of these studies, ten subjects stood on a vibration plate doing nothing for 15 minutes [19]. This had no (significant) effect on testosterone or growth hormone levels. However, in a study where they did isometric squats (remaining stationary in a “sitting position”), an effect was observed [18]. In that study, growth hormone increased by 300% and testosterone showed a slight increase of 7%. You might think of this study: “Was it due to the isometric squat, or did the vibration plate itself also have an effect?” That’s why the study by Kvorning and colleagues is interesting [20]. They compared three situations. Squatting without weight on a vibration plate, squatting with weight (8-10RM) without a vibration plate, and finally, squatting with weight (8-10RM) on the vibration plate. Comparing the latter two should demonstrate the added value of the vibration plate. They measured immediately after the exercise and 15 minutes later. Squatting with weight on the vibration plate resulted in the largest increase in growth hormone (20% immediately after training and 23% after 15 min). So, the vibration plate + squatting led to a greater increase in growth hormone than squatting alone (4% and 5%). However, it is also noteworthy that squatting without weight on the vibration plate led to a greater increase in growth hormone (7% and 12%) than squatting with weight without a vibration plate.

Conclusion Part I: Vibration Training Works in Theory

We have seen that in theory, there is enough to be said for the use of a vibration plate and vibration training in general. The acceleration through vibration increases G-forces, the tonic vibration effect makes muscles more efficiently used, and it can have a positive effect on testosterone and growth hormone levels when trained on a vibration plate.

Part II: Effectiveness of Vibration Training in Practice

In the next part about vibration training, we will look at what this means in practice. Does this potential increase in testosterone and growth hormone also lead to more muscle growth or fat burning? Do you actually become stronger and more muscular due to the tonic vibration effect and higher G-forces? You’ll find out soon on Fitsociety!

References

1. Tankisheva, Ekaterina MD; Bogaerts, An PhD; Boonen, Steven MD, PhD; Delecluse, Christophe PhD; Jansen, Paul; Verschueren, Sabine M.P. PhD. Effects of a 6-month local vibration training on bone density, muscle strength, muscle mass and physical performance in postmenopausal women. Journal of Strength & Conditioning Research:Post Acceptance: May 16, 2015
2. lifestylelaboratory.com/portfolio_john/discovery-center.html
3. Issurin, VB, Liebermann, DG, and Tenenbaum, G. Effect of vibratory stimulation training on maximal force and flexibility. J Sports Sci 12: 561-566, 1994.
4. Biermann, W. “Influence of cycloid vibration massage on trunk flexion”. American Journal of Physical Medicine1960 (39): 219–224.
5. Kunnemeyer J, Schmidtbleicher D.: Die neuromuskulaire stimulation RNS, Leistungssport 2: 39-42, 1997.
6. “Mars 500 Scientific Protocols”. European Space Agency. Retrieved 31 January 2013.
7. nasa.gov/mission_pages/station/research/experiments/976.html
8. Crewther, B, Cronin, J, and Keogh, J. Gravitational forces and whole body vibration implications for prescription of vibratory stimulation. Phys Ther Sport 5: 37-43, 2004
9. Owen, GJ. The influence of whole body vibration on knee extensor stiffness and functional performance. Master’s thesis, Auckland University of Technology, Auckland, New Zealand, 2004.
10. Roelants, M, Verschueren, SMP, Delelecluse, C, Levin, O, and Stijnen, V. Whole-body-vibration-induced increase in leg muscle activity during different squat exercises. J Strength Cond Res 20: 124-129, 2006.
11. Yue, Z, Kleinoder, H, and Mester, J. A model analysis of the effects of wobbling mass on whole-body vibration. Eur J Sport Sci 1: 1-19, 2001.
12. Donaldson, C and Ross, A. Whole body vibration: useful or useless for athletes. Presented at: New Zealand Academy of Sport (South) Strength and Conditioning Forum, Dunedin, New Zealand, 2006.
13. Cardinale, M and Lim, J. Electromyography activity of vastus lateralis muscle during whole-body vibrations of different frequencies. J Strength Cond Res 17: 621-624, 2003.
14. Martin, BJ and Park, H. Analysis of the tonic vibration reflex: influence of vibration variables on motor unit synchronization and fatigue. Eur J Appl Physiol 75: 504-511, 1997.
15. Bosco, C, Cardinale, M, Tsarpela, O, Colli, R, Tihanyi, J, Von Duvillard, S, and Viru, A. The influence of whole body vibration on jumping performance. Biol Sport 15: 157-164, 1998.
16. Bosco, C, Colli, R, Introini, E, Cardinale, M, Iacovelli, M, Tihanyi, J, Von Duvillard, S, and Viru, A. Adaptive responses of human skeletal muscle to vibration exposure. Clin Physiol 19: 183-187, 1999.
17. McBride, JM, Porcari, JP, and Scheunke, MD. Effect of vibration during fatiguing resistance exercise on subsequent muscle activity during maximal voluntary isometric contractions. J Strength Cond Res 18: 777, 2004
18. Bosco, C, Iacovelli, M, Tsarpela, O, Cardinale, M, Bonifazi, M, Tihanyi, J, Viru, M, De Lorenzo, A, and Viru, A. Hormonal responses to whole-body vibration in men. Eur J Appl Physiol 81: 449-454, 2000
19. Di Loreto, C, Ranchelli, A, Lucidi, P, Murdolo, G, Parlanti, N, De Cicco, A, Tsarpela, O, Bosco, C, Sauteusanio, F, Bolli, GB, and De Feo, P. Effects of whole-body vibration exercise on the endocrine system of healthy men. J Endocrinol Invest 27: 323-327, 2004.
20. Kvorning, T, Bagger, M, Caserotti, P, and Madsen, K. Effects of vibration and resistance training on neuromuscular and hormonal measures. Eur J Appl Physiol 96: 615-625, 2006.