Television personality Brooke Burke appeared in a commercial for Skechers Shape-ups touting the shoes beneficial effects on fitness and appearance

Television personality Brooke Burke appeared in a commercial for Skechers' Shape-ups touting the shoes' beneficial effects on fitness and appearance

If it sounds too good to be true, it probably is. But even so, millions of consumers around the world fell for claims that toning shoes would provide more weight loss, and more muscle tone than regular fitness shoes - catapulting the sector to sales of around $1bn in 2010.

Now, though, a warning shot has been fired to footwear firms, telling them to shape up their proof or tone down their claims if they want to avoid hefty fines.

Footwear firm Skechers USA this week agreed to pay $50m to settle what are described as "unfounded" advertising claims that its toning shoes - including the Shape-Ups, Resistance Runner, Toners and Tone-Ups lines - would help wearers improve their fitness and lose weight. Of this sum, $45m will go towards refunds to settle customer complaints.

It's the second time in just eight months that the Federal Trade Commission has forced a company to reimburse consumers after making far-fetched claims about their products.

In September last year Reebok, a unit of German sportswear giant Adidas AG, said it would pay $25m in refunds after claiming its EasyTone and RunTone shoes would provide extra tone and strength to leg and buttock muscles.

Both Skechers and Reebok say they stand behind their technology - which in Reebok's case includes a balance pod system invented by a former NASA engineer - and will continue to make and sell the toning shoes which retail at up to $100 a pair.

"Overhyped advertising claims"
But regulators at the Federal Trade Commission, which is trying to clamp down on "overhyped advertising claims," say Skechers' claims "went beyond stronger and more toned muscles" to include weight loss and cardiovascular health.

Some adverts for Shape-ups shoes included an endorsement from a chiropractor named Dr Steven Gautreau, who recommended the product based on the results of an "independent" clinical study he carried out.

But the trade commission found Skechers had failed to disclose that Dr Gautreau was married to one of its marketing executives, and had been paid to conduct the study.

Another Skechers ad said its Resistance Runner shoes would raise muscle activation by up to 85% for posture-related muscles, 71% in the buttocks, and 68% for calf muscles, compared to wearing regular running shoes.

The trade commission said Skechers "cherry-picked results" from the study and "failed to substantiate" the claims.

For its part, despite being is barred from making any health or fitness-related claims about its toning shoes unless they are true and backed by scientific evidence, Skechers says it fully stands behind the category.

It is permitted under the settlement to continue to advertise that "wearing rocker-bottom shoes like Shape-ups can lead to increased leg muscle activation, increased calorie burn, improved posture and reduced back pain," says Skechers president Michael Greenberg.

He adds: "The company has received overwhelmingly enthusiastic feedback from literally thousands of customers who have tried our toning shoes for themselves and have written unsolicited testimonials about their positive experiences. We remain committed to the continued development of our toning shoe products.

Recapturing lost sales
Not surprisingly, there's a lot at stake as the once-booming sector struggles to recapture lost sales.

Shoes that employ so-called toning technology feature a rocker bottom outsole design which, unlike flat-bottomed athletic footwear, creates instability with each step and forces muscles to work harder.

They have been available in the US for more than 15 years, but sales surged dramatically in 2009 to $145m - an eight-fold rise on the $17m in revenues generated the year before - peaking in 2010 at close to $1bn.

However, as more and more firms stepped into the market, too many products and falling prices were just some of the challenges bigger brands had to face. And, along with a realisation among consumers that the footwear didn't necessarily live up to the hype, the entire category faced backlash - with sales halving in 2011.

For Skechers, which was the market leader in the toning footwear category, the shake-out of the category has hit hard. In the 12 months to 31 December, the firm swung to a loss of $67.5m, from a profit of $136.1m the year before, as slowing demand for its toning lines contributed to a 20% drop in net sales to $1.6bn.