Even the biggest shoe addicts don’t believe that a new pair will change your life (unless you’re talking about Jimmy Choos…) But the life-changing claim is exactly what many footwear brands are saying these days. The supposed miracle-workers: “toning shoes” incorporating a new design that will help you slim down and firm up just by taking a walk. But can a pair of shoes really help you reduce your bum and thighs? We asked the experts whether the sneakers, which cost anywhere from $70 to $400, are worth it.

What they claim: An innovative design gives you an automatic workout while you wear them, without having to do any exercise – other than walk, of course. Among the much-touted benefits: Compared to your regular sneakers, you will use three times as much energy while walking, tone your buttocks and thighs, and even (according to some manufacturers) relieve joint pain.

How they work: These shoes are built with an unstable sole that rocks back and forth and forces the wearer to use her muscles in a different way. “They are incorporating what they refer to as ‘wobble board technology,’” explains Dr. Emily Splichal, a New York Sports Club trainer and podiatrist. “They claim that because you are on this sort of rocking chair, you have to engage your abdominals at all times…[they work] the legs and the glutes and the entire body as you’re walking or standing because you’re on this unstable shoe or rocker.”

When to wear them: These shoes are made for walking – no running or weight lifting allowed. “I would not run in them,” Splichal says. “They have a higher heel, you’re kind of elevated and if you were to step wrong…I wouldn’t want to see an injury based on them.” John Rowley, Director of Fitness & Wellness at The American Institute of Healthcare & Fitness in North Carolina and author of Climb Your Ladder of Success Without Running out of Gas, says to avoid wearing them during weight-bearing exercises. (This type of exercise includes low-impact aerobics and using stair-step machines.) “Adding weight just accentuates everything, and if the shoes are throwing you off balance, the weight will become much more dangerous.”