Shaky Ground: Spurred by positive research, some clubs are turning to vibration machines to offer time-efficient workouts, but not all researchers are sold on the technology.
Astronauts and health club members may seem to have little in common, but these days, some health club members are turning to a technology used in the Russian space program to help them in their fitness pursuit.
Russian astronauts used whole body vibration (WBV) to avoid a loss of muscle strength and body mass during prolonged stays in space. Today, a growing number of manufacturers offer this technology in the United States to professional and university athletic teams as a way to build strength and reduce the recovery time from injuries. More recently, manufacturers have begun offering the equipment to the general public through fitness facilities and home equipment sales. But the growing use isn't without controversy.
In general, proponents of WBV say it uses high-frequency vibration to increase the number of muscle fibers, improve flexibility by releasing connective tissue, increase circulation due to the muscle pumping action and provide a hormonal kick. WBV machines offer a vibrating platform on which users can sit, stand or perform exercises for a warm-up, neuromuscular core work, strength training or an active cool-down.
The frequency of the vibration can range from 3 Hertz to 50 Hertz depending on the model and manufacturer. The WBV technology varies from one manufacturer to the next. One vendor's machine evenly disburses vibration through air suspension. Another vendor's machine uses plates that go up and down to activate muscle contractions between 25 and 50 times per second. Still another vendor's machine features a teetering mechanism that seesaws from left to right so that users' hips pivot from side to side.
The technology sounds simple enough, but research studies have been evenly split on the effectiveness of WBV, says Wayne Wescott, fitness director for South Shore YMCA in Quincy, MA. Some researchers have been critical of the effects of high-amplitude vibration on the body, but other research has shown benefits from the use of WBV.
The lack of consensus on the effectiveness and safety of this technology may come from the relative newness of the technology and the research about it. Along with other researchers, Bill Amonette, an exercise physiologist who studied WBV at Johnson Space Center and who is a lecturer at the University of Houston-Clear Lake, discovered that the use of a vibration platform while performing squats makes muscles work more. However, he urges caution about some of the claims about the technology. It will take several years to figure out how best to use WBV, he says. Researchers are still looking for answers regarding the safe dosage of vibration over a given time.
“The research on vibration training is at the same state as resistance training was back in the 1960s,” Amonette says. “We know that it works, but we don't know the parameters that we're looking for before it becomes a dangerous device. It takes time for the literature to evolve.”
William Kramer, professor of kinesiology at the University of Connecticut, agrees, saying that more studies have been published in the last five years, but researchers still need to fill in the gaps.
“There is a lot of research that hasn't been done yet to understand all the prescriptions,” says Kramer, who is planning to study the effect of WBV on warming up the muscles and facilitating strength development. “We are still struggling with the paradigm of what works for different populations.”
Despite the need for more research, Amonette says that anyone reviewing existing studies that show negative effects from exposure to vibration should be cautious in interpreting the studies. Some of the studies were based on research of a modality other than vibration platforms and instead actually show the detrimental effects of exposure to vibration while standing on a jackhammer or driving a vibrating truck.
“You don't know the frequency or magnitude of the vibration on a jackhammer, but a vibration platform is much more predictable,” Amonette says.
Current research hasn't determined whether or not vibration is detrimental to joints, he says, and although he has never heard of anyone getting injured on a platform, some people are prone to injury and should use caution when using WBV. (See “Contraindications” sidebar on page 60.)
Although researchers are still studying the effects of WBV on the human body, some fitness facilities are investing in the equipment and offering WBV as part of private and group personal training sessions. Powerhouse Gyms International, Detroit, uses WBV machines in a few of its corporate-owned facilities, says CEO Henry Dabish, and he has found that having one to two machines in a club offers members a good way to get a full-body warm-up prior to beginning an exercise program or group exercise class.
Dabish says he doesn't see any additional risk with the WBV platforms compared to other pieces of equipment within the clubs, and he views WBV as a way to maintain members' interest by having the latest pieces of equipment in Powerhouse facilities.
Town Sports International (TSI), New York, has tested the machines in four of its clubs for two years. Ed Trainor, vice president of fitness products and services for the company, says he is impressed with the scope of the technology.
“Athletes are embracing it, and from coast to coast, elderly people are using it where they were previously unable to be put on a training machine to improve their flexibility and strength,” he says.
Andy Clay, owner of Blue Clay Fitness and Wellness in Beverly Hills, CA, has seen the effects of WBV on seniors first-hand. He says seniors who couldn't walk up and down stairs or get up off the floor are now mobile again after using the machines. Because members can exercise on the machines in a static position, even clients with a limited range of motion can benefit, Clay says.
“I haven't seen any other type of exercise that is more effective for older people,” he says. “For us as a company, it has become a major focus. Clients across the board have gotten dramatic results from this kind of training.”
Because proponents say that WBV speeds the recovery of damaged muscles and tendons, some college and pro sports teams' training centers also have invested in the machines. E.J. “Doc” Kreis, the head speed, strength and conditioning coach at the University of California at Los Angeles (UCLA), says WBV has been effective in treating athletes with injuries. UCLA bought two of the vibration machines after Kreis saw what the machines did to help some of the world's top athletes recover from Achilles tendon tears, he says.
Athletes and seniors aren't the only ones turning to WBV. Time-pressed individuals, such as corporate executives, can also benefit from the technology, Clay says. His business offers six boot camps a week at a publishing company in Malibu, CA. The trainers also offer one-hour private training sessions twice a week to the executives.
“They love it,” Clay says about the executives. “In 20 to 30 minutes, they can get whole body vibration [training] that would be like 60 to 90 minutes of standard resistance training.”
Deconditioned exercisers can also benefit from this technology, says Tony Swain, fitness director at East Bank Club in Chicago. The machine often appeals to individuals who don't want to spend all day sweating it out at the gym because they can achieve a workout in a short amount of time, he says.
“Some people don't want to go into a club and ride a bike and lift weights,” Swain says. “With these machines, they can get the benefits of resistance training in a shorter amount of time.”
WBV, however, is not a magic pill and is only a complement, Trainor says, not a replacement to traditional resistance training.
Amonette agrees, saying that WBV is just another tool that trainers can use to help improve power, bone density and flexibility in their clients. Resistance training and WBV each affect the muscle in different ways, and vibration can augment weight training.
“We awaken our nervous system through vibration, and if we do an exercise afterwards, we're very powerful after that,” says Amonette, who has been studying WBV for five years. “While it's used to enhance the metabolic response to resistance exercise, it's never going to replace it.”
Although experts caution against replacing aerobic and resistance exercise programs with WBV, fitness facilities are discovering ways to infuse the technology into their programming. They're also bringing in new revenue by charging an additional fee to their clients to use the equipment.
Swain plans to increase personal training revenues at East Bank Club by investing in four WBV machines, each of which take up about as much room as a chair, can be plugged into an outlet and use less power than a treadmill. The 35 personal trainers and 80 group exercise instructors at the four-story 450,000-square-foot East Bank Club will have the option to receive training on how to use the machines this month before Swain begins offering four-week classes and private sessions to the club's 10,000 members. To encourage the members to use the machines, Swain will strategically place them in high-traffic areas and later move them to a 700-square-foot personal training studio.
“Our ideal situation with the WBV is to be able to have as many members participate in a class who otherwise wouldn't lift on their own or would like a completely different type of workout, which may lead to more personal training sessions,” Swain says. “As we have seen here, many members will always prefer to stay in the friendly atmosphere of a small, social class.”
Although the prices have not been finalized, Swain tentatively plans to charge $25 per 25-minute class if members sign up for an eight-class session or $30 for a stand-alone class. Members will be able to purchase a certain number of minutes, and by using a key card, they can then operate the machine on their own. To make sure the members don't overuse the machines, they will only be able to purchase the plan in 10-minute increments.
“The ideal situation would be to recoup some of the cost of the machines,” Swain says. “For us, it will be a creative program within the class setting that will generate more personal training revenue.”
Clay charges his Blue Clay Fitness clients $200 for a one-hour WBV session, he says. He purchased eight WBV machines, paying about $10,000 for each, which is comparable to the cost of a high-end elliptical, he says.
At TSI, WBV training is offered as part of personal training packages. Trainor plans to charge members $1 per minute for key cards, which they can buy for a certain number of minutes.
Before allowing members to use the machines on their own, however, club owners should consider training them on how to use the WBV machines to get the maximum benefit and avoid pain or injury, Swain says. At East Bank Club, members will be offered two, 20-minute training sessions to familiarize them with the technology before they can buy minutes on the machine. TSI also allows members to only use the machines if they are supervised by personal trainers, Trainor says.
“It's too new to the industry to put in a club and turn the consumer on to it without having any guidance,” he says.
It's also too new for the technology to be truly affordable, Trainor says, adding that WBV won't truly take off until the cost of the machines decrease. Right now, they cost about twice as much as anything he would buy for any of his clubs, Trainor says.
However, so many brands have hit the market that prices have already started to drop, Dabish says. The technology has been big in Europe for a long time, and if it becomes more affordable, Dabish predicts that WBV's popularity should increase in the U.S. market in the next 18 months.
More research about the technology will also increase WBV's use in the United States, Trainor says, noting that more research will help reticent club owners more readily accept WBV.
“We don't know enough about it yet,” he says. “It took two years to get where it is today, and in the next two years, it will be so common that everyone will have tried it.”
Trainor even admits a hesitancy to jump all the way into WBV, saying that TSI plans to continue to research WBV and watch how the technology evolves over time.
“We have gotten great value from [the machines],” Trainor says. “But even if we were the front-runners in testing it, we want to wait and see.”
Researchers worldwide are studying whole body vibration (WBV) with mixed results:
A July 2007 study from the University of Hong Kong found that WBV was effective in improving the balancing ability in 69 women over the age of 60 without habitual exercise.
The University of Sweden discovered that long-term WBV exercise positively affected the leg muscular performance of untrained people and senior women, but no clear evidence existed for the effect of short-term WBV on muscular performance.
A Belgium university compared the effect of 24 weeks of WBV training on the body composition and muscle strength of 48 untrained females. The study found that the training did not reduce weight, total body fat or subcutaneous fat in the women. However, it led to a gain in strength comparable to following a standard cardio and resistance training program.
German researchers found that WBV may be an effective and time-efficient tool to enhance glycemic control in Type 2 diabetes patients.
Source: PubMed
Users should check with their doctor before training on whole body vibration (WBV) machines. Because of the high-speed contraction of the muscles, WBV shouldn't be used by people with tremors, muscle twitches or neuromuscular diseases, says Wayne Wescott, fitness director for South Shore YMCA in Quincy, MA. Here are other risk factors: