Vibration training uses a fitness machine to vibrate the entire body, which acts to give the body a workout and tones muscle. The National Aeronautics and Space Administration has conducted studies focused on reducing muscle atrophy and bone loss in zero gravity environments, such as those faced by astronauts on long missions. The research found that the tiny vibrations produce nearly normal bone formation in rats. While NASA's research continues, vibration training is touted as a quick fix alternative to traditional strength training exercises.
Vibration has been recognized as a component in the development of back pain in people who experience long-term vibration, such as truck drivers and helicopter pilots. Vibration training may result in back pain. Vibration has two components – frequency and amplitude. In the same way you can shake your fist up and down, a vibration machine moves you up and down. The frequency is how fast you are shaking your hand. The amplitude is the distance your fist travels. According to the biomedical engineering department at Stony Brook University, high frequencies and large magnitudes associated with vibration over extended periods of time contribute to back pain.
At least one manufacturer of vibration training machines warns against people with certain conditions from using the machine. People who are pregnant, who have retinal detachment, blood clots and bone tumors should avoid vibration training. These people face special risks due to their conditions because of the effects of vibration. Although the vibration levels experienced in training machines may not cause damage, it is true that high levels of vibration of the human body can cause damage to bone and connective tissue, an unwelcome effect for a person suffering from a retinal detachment.
Some people warn that vibration machines can result in brain damage and even death. Clinton Rubin, a biomedical engineering professor at State University of New York at Stony Brook, is concerned about the long-term exposure to vibration and says there is the risk of brain damage. This concern stems from the chronic exposure to vibration, which is different from the occasional workout. Nevertheless, much of the historical research on vibration was performed to minimize the exposure to vibration because it was recognized that chronic exposure poses a risk.