There's a whole lot of shaking going on in gyms these days.

The machines responsible may look like locker room scales on steroids, and the idea of using them to jiggle the flab away may seem a bit wacky. But experts, celebrities and true believers say that squatting and pressing atop these vibrating platforms can perk up tired bodies and ignite weary workouts.

"Vibration training improves muscle tone and increases core body temperature because it allows for stimulation of the neurological system," David Harris, director of personal training for the Equinox Fitness, said in an interview.

Over 100 gyms in the United States and more than 80 countries worldwide feature the vibrating platforms, according to Patty Stapleton, spokesperson for Power Plate, the California-based company which manufactures them.

Model and television presenter Heidi Klum, actors Clint Eastwood and George Clooney, and entertainers P-Diddy and Madonna are among its celebrity users, according to the company.

"Many people are using the machines to improve flexibility and reduce muscle soreness," Fabio Comana, an exercise physiologist and spokesperson for the American Council on Exercise (ACE), said in an interview.

"There is quite a bit of research from Europe and United States to support some of the benefits," said Comana, who teaches at the University of California at San Diego.

The principles of whole-body vibration therapy were originally developed for the Russian space program to combat the degenerating effects of zero gravity on muscle and bone.

Scientists found that vibrating therapy allowed cosmonauts to stay in space for up to three months longer.

Russian Olympic trainers began using it in the 1970's to improve their athletes' competitive edge, and in 1999 Dutch trainer Gus Van de Meer designed a device for the fitness community.

But really the technology reaches back much further — to 1687 and Sir Isaac Newton's second law of motion.

"It works on Newton's principle where force equals mass times acceleration," Comana explained.

"The vibration activates neurological systems and muscle response. It also places stress on the bones to increase their density and it certainly stimulates blood flow, improves flexibility and reduces muscle soreness," he said.

The company recommends exercising on the platforms for three to four 30-minute sessions per week.

"I favor dumbbell squats and overhead presses," Comana said. "But whatever you chose to do on the platform, you are limited to static movements, given how small it is."

He added that the size of the platform is the major limitation to vibration technology.

"I favor exercises that are more dynamic," he said.

And while the spirit may be willing, there is a limit to how much vibration the flesh can tolerate.

"Many feel their brains are becoming jelly or their fillings will fall out," Comana said regarding the higher intensities.

"The average consumer tries it for a while and then grows bored with it quite quickly," he concluded.

As for company claims that their product can reduce cellulite, for so long the holy grail to exercise technologies, massage lotions, personal trainers and wellness centers across the globe, Comana is skeptical.

"It certainly stimulates blood flow, and it can improve flexibility and reduce muscle soreness," he said.

"With regard to cellulite, I would say, no," he added. "What are we, shaking it away? Lots of luck!"