Futuristic footwear

They’re everywhere: Running shoes with funny-looking soles that claim to work out your legs with every step you take. (Not to mention reduce cellulite, lessen pressure on your joints, and, oh yeah, leave men speechless.) The principle is that through curved, high-tech soles, they mimic how humans were intended to walk: barefoot, and on uneven ground. By creating instability, this fancy footwear forces you to constantly readjust your body, strengthening all your leg muscles, says Benno M. Nigg, professor of biomechanics at the University of Calgary and a researcher for Masai Barefoot Technology, the company that has made curved-soled shoes since the ’90s. Here are three popular options that work while you walk:

MBT (Masai Barefoot Technology)
With its curved sole available in 64 styles, from runners to boots and sandals, you can stay comfortable and work your muscles harder at any time of day. The company has done a ton of research, including some through professors like Nigg. Their footwear, Nigg says, gradually strengthens and tones your legs. The price, ranging from $149 to $425, gets you a pair of the shoes plus an introductory DVD that will help improve your gait.

Reebok Easytone
The Reebok Easytone uses less visible balance pods – no tell-tale curved soles here – that are built in under the heel and ball of each foot to make your muscles work harder. They increase muscle activation by up to 28 percent, which tones your legs over time. And at $99, they are one of the most accessible ways to take your workout with you wherever you go.

Skechers
A more youthful brand, Skechers recently introduced Shape Ups, which rely on “a rolling bottom, soft-foam insert and dual-density midsole” to make you less stable and push your leg and butt muscles into action (although we’re skeptical of the website’s claims that they’ll reduce cellulite). Plus, the site offers tips, like to limit your walking to 25 to 45 minutes per day for the first two weeks, and instructional videos to help you get the most from them. There are 15 styles to choose from, most of which look like a chunkier version of what you would usually exercise in, at prices from $145 to $250.