They may look funny, but they’re the hottest new thing in the shoe business. Toning shoes promise more than comfort. They promise to give you a workout while you walk.
The ads for the top-selling Shape-ups by Skechers claim: “Now you can get in shape without setting foot in a gym.”
No wonder sales of toning shoes are expected to hit $1.5 billion this year, a whopping 400 percent increase from 2009.
But can toning shoes deliver on their promise? Do you really get more exercise and burn more calories for each step walked?
To find out, the American Council on Exercise (ACE) commissioned a study at the University of Wisconsin at La Crosse. Researchers compared people walking on a treadmill wearing a regular running shoe by New Balance and three brands of toning shoes: Skechers Shape-ups, Rebook EasyTone and MBT shoes from Masai Barefoot Technology.
The test subjects walked for 5 minutes wearing each of the shoes at 3 mph, 3.5 mph and 3.5 mph with a 5 percent grade. While they walked, the researchers monitored their heart rate, oxygen consumption and muscle usage (abdominals, butt, quadriceps, hamstrings and calves).
“Based on our research, we saw absolutely nothing,” says John Porcari, Ph.D, director of the University’s clinical exercise physiology program. “There was not even a hint of something going on.”
The study found there was no difference between the regular running shoe and any of the toning shoes when it came to heart rate, oxygen consumption, calories burned or muscle activity.
“This doesn’t make the shoes bad or a total waste of money,” says Cedric Bryant, ACE’s chief science officer. “But you could achieve the same things with normal running shoes.”
Toning shoes with their “rocker-bottom” soles are deliberately designed to be a bit unstable. The idea is to mimic what happens when you walk barefoot in the sand.
“It’s very intuitive,” says Leonard Armato, president of the fitness group at Skechers USA. “Walking on sand will be more effortful than walking on a hard surface.”
Armato says this extra effort makes your muscles work harder than when you wear normal athletic shoes, which results in more toning and more calories burned.
Skechers and Reebok are the two big players in the toning shoe market right now. Reebok says its EasyTone shoes are designed to “tone and strengthen key leg muscles with every step.”
Skechers claims its Shape-ups will do even more:
“Shape-ups are designed to help you strengthen your muscles, including your back, abdomen and calves. Shape-ups will help you lose weight and improve your circulation, creating a healthier you!”
If you believe the ads, Shape-ups will also improve posture, reduce stress on your back and legs, firm your buttocks and tone your thighs – even reduce cellulite.
Both companies say their claims are backed by scientific research and supported by hundreds of thousands of happy customers.
Skechers’ Leonard Armato calls the ACE study “flawed, flimsy and based on junk science.” He insists five minutes on a treadmill is not adequate to test these shoes.
“There are more than 30 studies that we know of that support the benefit of rocker-bottom shoes,” Armato says. “So the evidence is overwhelming that these products actually work.”
Armato tells me Skechers has received more than 15,000 unsolicited testimonials from customers who “testify that Shape-ups have changed their lives in a very positive way.”
Reebok also questions the validity of the ACE study. In a written statement to MSNBC.com, the company says:
“Reebok has never claimed that by wearing EasyTone a person will burn more calories or that EasyTone is a ‘magic bullet’ that will replace exercise. EasyTone is a great way to get more muscle activity from your daily routine and can be a beneficial part of a healthy fitness lifestyle. Reebok is a fitness company with a long heritage and history and our goal is to help people have fun while staying in shape. EasyTone is one way they can do this.”
I also contacted MTB, and here is the e-mail response: "Independent research and published studies have shown the benefits of our footwear. We stand by the conclusions of that research and those studies."
Unhappy customer sues Skechers
Last month, a class action lawsuit was filed against Skechers by a woman in California. Venus Morga says she bought a pair of Shape-ups and did not experience any of the promised benefits.
In her lawsuit, Morga claims the company’s “false and misleading advertising campaign has allowed it to reap millions of dollars of profit at the expense of the consumers it misled.” The complaint also alleges that some people have been injured by wearing Shape-ups.
Armato calls the lawsuit “a frivolous claim,” and predicts Skechers “will prevail in the end.”
Potential downsides of toning shoes
Toning shoes are designed to be unstable, which could cause problems for people who already have trouble maintaining their balance.
At Consumer Reports, Dr. Orly Avitzur, MD, is concerned that seniors who wear toning shoes could increase their risk of falling, which could result in hip fractures or other serious injuries.
“They are touted as this big miracle and actually for certain folks, they can be quite dangerous,” she says. “So if there’s no real advantage and some people risk falls, I think it’s actually more risk than reward.”
Eric Heit, DPM, who heads the podiatry section at Seattle’s Virginia Mason Medical Center, tells me toning shoes “redistribute the forces of walking” which can cause low back or knee pain.
That’s what happened to one of his patients, Brenda Moa, who walks on a concrete floor all day at her job. Moa says her knees and lower back started to hurt as soon as she started wearing the Shape-ups shoes.
“They were really wobbly and you could easily trip with them. I felt like I was drunk all the time,” Moa says. “I’m not a fan of these shoes. I wouldn’t buy another pair.”
Last year, the UC Berkeley Wellness Letter weighed in on toning shoes. The editor warned that they “may alter the biomechanics of your normal gait and your stride,” making it hard for you to switch back to your regular shoes.
“Rather than invest in these shoes,” the Wellness Letter suggested, “you can try going barefoot more often at home to build foot strength and flexibility – unless you have a condition, such as diabetes, that impairs circulation in the feet.”