By ANDREW MARTIN and ANAHAD O’CONNOR
More dashed hopes for those seeking a perfect derrière — and the once highflying industry of toning shoes and clothing that promotes such ambitions.
Those fancy Reebok sneakers that promise better legs and a better behind “with every step” may be just like every other sneaker, federal regulators said Wednesday, and Reebok International is liable for $25 million in customer refunds for making false claims about its EasyTone line.
“Consumers expected to get a workout, not to get worked over,” said David Vladeck, director of the Federal Trade Commission’s Bureau of Consumer Protection.
Mr. Vladeck declined to say whether investigators would pursue other manufacturers of toning sneakers, but the punishment — unusually severe for the agency — has shaken an industry already struggling with inventory pileups and lawsuits challenging the truth of its fitness claims.
Sales of toning footwear topped $1 billion last year. But in the first eight months of this year, sales were off 46 percent compared to the same period a year earlier, according to data from the NPD Group.
“This is going to hurt,” said Michael Atmore, editorial director at Footwear News, a trade publication. “This comes at a time when the category is on the wane.”
Despite agreeing to the settlement, Reebok, a unit of Adidas, said it did not concur with the agency’s conclusions.
“In order to avoid a protracted legal battle, Reebok has chosen to settle with the F.T.C.,” said Daniel Sarro, a company spokesman, in an e-mail.
“We stand by our EasyTone technology,” he added. “We have received overwhelmingly enthusiastic feedback from thousands of EasyTone customers, and we remain committed to the further development of our EasyTone line of products.”
The American depository receipts for Adidas fell $1.35 euros ($1.83) to 47.86 euros ($64.89) on the Frankfurt exchange on Wednesday.
Reebok introduced the shoes and their “balance ball-inspired technology” in 2009 with a tantalizing proposition.
Just wearing the sneakers, Reebok said, would tone and strengthen a customer’s legs 11 percent better than regular walking shoes and sculpt bottoms 28 percent better.
Toning sneakers are designed to create slight instability, forcing muscles to work harder and so become more shapely and strong. Reebok offered toning versions of running shoes and sandals, too. The company’s ads for the shoes featured the toned behinds of scantily clad women and promised attention-grabbing results.
Toning shoes became an instant sensation, with sales ballooning to $1.1 billion last year from $50 million in 2008, said Matt Powell, an analyst at SportsOneSource. Reebok sold less than one million pairs in 2009, but that rose to more than five million pairs in the United States alone the next year, most of which sold for $100 or more.
A spokesman for Skechers, the market leader in toning footwear, declined to comment, but in a regulatory filing in August, the company said it had given the F.T.C. information on its advertising for toning shoes. The company also said it had stopped using certain test results in its ads.
“We believe that our claims and advertising with respect to our core toning products are supported by scientific tests,” the company said.
Mr. Vladeck said the evidence supporting Reebok’s marketing claims was “wholly insufficient,” though he declined to describe the nature of the evidence. Customers who bought EasyTone shoes can fill out an application for a refund at the F.T.C.’s Web site, at www.ftc.gov.
Reebok stopped using advertising that made the disputed health claims last year, and under the settlement, it is prohibited from making them again unless it can provide more robust scientific proof.
Mr. Sarro, of Reebok, said the company had used electromyography and “other standard testing that the F.T.C. felt was inadequate.”
“While we didn’t agree, we discontinued our objective claims in 2010 that were based on that testing,” he said.
The idea for Reebok’s toning shoes came from Bill McInnis, a former NASA engineer, who wanted to use the technology behind balance balls in shoes.
To back up its claims, Reebok commissioned a 2008 study at the University of Delaware in which five women wore EasyTone shoes, regular shoes or no shoes and walked on a treadmill for five minutes, as electrodes recorded muscle activity. It is not known if Reebok provided additional research to the F.T.C.
Nonetheless, the agency is not the first to question whether toning shoes work. As the shoes became more popular, Reebok and its competitors grappled with a growing number of lawsuits claiming false advertising or injuries caused by the shoes.
“We get calls and e-mails every single day,” said Ronald Johnson, a lawyer in Kentucky who has filed five suits against Skechers in federal court. “There are lots of people we have who put them on, went out for a walk and snapped their ankles that day.”
Last year, a study financed by the American Council on Exercise and carried out by researchers at the University of Wisconsin, La Crosse, found that three types of toning shoes, including EasyTones, offered no greater muscle activation or calorie-burning than ordinary gym shoes.
“There is simply no evidence to support the claims that these shoes will help wearers exercise more intensely, burn more calories or improve muscle strength and tone,” the authors concluded.
Even the advertising industry’s self-regulatory arm, hardly known for being tough, concluded earlier this year that Reebok did not have enough proof to support its advertising.
Noting that the University of Delaware study included only five subjects, the National Advertising Division of the Council of Better Business Bureaus concluded that “results that suggest potential toning are clearly insufficient to support unequivocal claims that you will ‘tighten and tone with EasyTone.’ ”
Mr. Powell, the analyst, said he did not think the additional bad publicity would have much impact. While the market is now warm rather than red hot, he said, customers who buy toning shoes like them because they are comfortable, not because they will make them more buff.
“All the brands invited more scrutiny because the claims were relatively outrageous,” he said. “Regardless, customers really like these shoes.”
A version of this article appeared in print on September 29, 2011, on page B1 of the New York edition with the headline: Reebok to Pay $25 Million Over Toning Shoe Claims.