FitFlops: Do They Really Sex Up Your Legs?

Forget the iPhone and Harry Potter. Turns out the slickest summer marketing hit may just be a pair of flip- flops.  They don’t look like much, but it’s what they promise—a tighter butt and trimmer legs—that’s hitting the buzz spot.

The cushy-soled shoes, dubbed FitFlops, have been selling out faster than most stores can stock them. One mass e-mail blast from the developers was enough to move 4,000 pairs in three hours when the product launched in Britain in May. In a London shoe store—where the waiting list ran into the thousands—things got so heated one woman shoved another off a chair in a bid to get the last pair in stock. (“That was a bit extreme,” storeowner Anthony Stiefel told NEWSWEEK.) The FitFlop craze hit the U.S. a month later, with similar force. The first shipment sold out in weeks, the second in days. After a segment on “Good Morning America,” the shoe’s Web site promptly got 57,000 hits. America Online repeatedly listed the $45 FitFlops as one of its top search terms; customers posted online testimonials singing the sandals’ praises and bloggers had a field day. “It just went crazy,” says Marcia Kilgore, the Bliss Spa chain founder who came up with the idea for her new company, Brandhandling.

Kilgore, who moved to the U.K. in 2004, says she hadn’t anticipated the demand. Developed by her small organization “sort of as a sideline,” the FitFlop design did not get finalized until less than two months before launch. By that time, she recalls, there wasn’t much time left to show it to many merchandisers. Indeed, the overall numbers for FitFlops fall far short of the noise level about the product. Projected U.S.-U.K. sales figures are about 300,000 for the summer; projected income about $10 million. But if that’s small potatoes for footwear giants like Nike, which generates about $15 billion in annual revenues, it’s a big success for a new seven-staffer company like BrandHandling.

Certainly there’s genius at work behind FitFlops. But it may be more in the hype than in the biomechanics. Kilgore says that FitFlops are designed to increase the duration and intensity of muscle activity by destabilizing the foot as the wearer walks in them. “Certain muscles are loaded more, so they have to work harder to achieve the same step. In other [slow twitch] muscles, they’re activated for a longer period of time,” she says. Two studies funded by BrandHandling—one by the shoe’s creator, David Cook, and the other by sports biomechanist Philip Graham-Smith at Britain’s University of Salford—seem to bear out this claim. Skeptics, however, point to the miniscule size of these studies. Cook tested only five women; Graham-Smith studied eight. Graham-Smith, the head of the university’s Directorate of Sport, said he found that six of the eight—all “nonsporty” students in their 20s—showed “significant improvements” after wearing the sandals for a few days. “Ideally, you’re looking for a lot more than eight [subjects], but eight was all that we could get through in the time frame that we had,” he says.

Others are less convinced. Doug Gurley, an orthopedic surgeon and sports-medicine specialist at the San Juan Regional Medical Center in Farmington, N.M., says he’s “highly suspicious” of the claim that destabilizing the foot has any health or fitness benefit. “It’s all marketing, no science.” And New York physical therapist Chris Delahanty described the claims for the shoes as “just ridiculous.” "Unless you've got an incredibly de-conditioned foot, nothing like this is even going to affect it," says Delahanty. “The fact that there’s increased activity could mean that you’re walking differently—it doesn’t mean that you’re strengthening the muscle. You have to exercise at a certain level for a certain amount of time to get any increased muscle strength.”

“Ridiculous” may be a bit harsh. Fitness and footwear history is littered with more egregious—and potentially harmful— examples. In the 1940s, Clifford Brooks Stevens (who popularized the phrase "planned obsolescence") designed an X-ray machine  to determine the most accurate shoe sizing (the notion at the time was that your foot would be damaged if your shoes weren't properly sized). The machines were placed in thousands of department stores, but banned in most states by the 1970s because radiation hazards. Then there was the Relaxacisor a mini electro-shock box that sent electrical currents into muscles through “contact pads.” That too, was eventually banned by the FDA in the ’70s due to the risks of miscarriages and epileptic seizures.

Nor is Kilgore, whose successful marketing and sale of the upscale Bliss brand has given her street cred in the business world, put off by the naysayers. “I’ve lived my entire life with people calling me ridiculous,” she says. “With anything new, trail-blazing, you will have people who say it’s ridiculous, many of whom wish they had thought of it themselves. It’s always easier to attempt to knock someone off the top of the hill than to get out and climb it yourself.” Of course, if you do climb hills yourself you’re likely to get that firmer butt and thighs anyway—with or without the wobbly shoes.