Sportswear maker Reebok International Ltd is to pay $25m in customer refunds after making unsupported claims that its toning footwear would help wearers improve their fitness.

The settlement order from the US Federal Trade Commission yesterday (28 September) came after Reebok claimed its EasyTone and RunTone shoes would provide extra tone and strength to leg and buttock muscles.

But the FTC, which is trying to clamp down on overhyped advertising claims, said the company "deceptively advertised" the products.

Reebok's $25m settlement will be made available for consumer refunds either directly from the FTC or through a court-approved class action lawsuit.

"The FTC wants national advertisers to understand that they must exercise some responsibility and ensure that their claims for fitness gear are supported by sound science," said David Vladeck, director of the FTC's Bureau of Consumer Protection.

Reebok's EasyTone walking shoes and RunTone running shoes sold for $80 to $100 a pair, while EasyTone flip flops retailed for about $60 a pair. Ads for the shoes claimed that sole technology featuring pockets of moving air creates "micro instability" that tones and strengthens muscles as wearers walk or run.

But the FTC said advertising claims they strengthened and tone key leg and buttock muscles more than regular shoes were "unsupported."

It added that Reebok also "falsely claimed" that walking in EasyTone footwear had been proven to lead to 28% more strength and tone in the buttock muscles, 11% more strength and tone in the hamstring muscles, and 11% more strength and tone in the calf muscles than regular walking shoes.

Under the settlement, Reebok is barred from making any health or fitness-related claims about its toning shoes and other toning apparel unless they are true and backed by scientific evidence.

But Reebok, a unit of Adidas AG, says: "Settling does not mean we agree with the FTC's allegations; we do not." Instead it vows: "We stand behind our EasyTone technology...and we remain committed to the further development of our EasyTone line of products."