r maybe too good to be true All of the above are publicized claims marketing the latest toning shoes from Skechers Shape-Ups, MBT (Masai Barefoot Technology) and Reebok EasyTone. The shoes, each of which uses uniquely shaped rounded soles and extra cushioning to alter the wearer's normal walking gait, are currently all the rage in footwear. A quick Web search reveals many blogs touting the shoes and NFL great Joe Montana has even been hired as a pitchman for one of the brands. With all this buzz about toning shoes, it was time to put their claims to the test. So we enlisted a team of exercise scientists from the Exercise and Health Program at the University of Wisconsin, La Crosse, to study each of the shoes.
The basic theory behind how they are supposed to work makes sense to consumers, so it's easy to see why many are quick to embrace—and purchase—the shoes, which range in price from $100 to $245. The common denominator is that they all have an unstable sole design, which forces the wearer's body to constantly struggle to find an equilibrium or balance point. The MBT and Skechers have rounded sole designs, while the Reebok shoes have 1 cm-diameter pods built into the forefoot and heel. "It makes sense," says John Porcari, Ph.D. "People say, 'I can feel them working my muscles more because I'm unstable.'" To make the shoes even more enticing to consumers, Skechers, MBT and Reebok each cite their own studies "proving" the results one can expect from wearing their shoes. What they fail to mention, however, is that these studies are not peer-reviewed, and most are of questionable design. For this reason, ACE's Chief Science Officer Cedric Bryant Ph.D., urges consumers to beware
of studies sponsored by manufacturers. "Depending on how they conduct the study, they can prove anything they want to prove."
The Study
To test the effectiveness of the shoes and evaluate their claims, a team led by Porcari, John Greany, Ph.D., Stephanie Tepper, M.S., Brian Edmonson, B.S., and Carl Foster, Ph.D., designed a pair of studies, one evaluating exercise responses to walking in traditional athletic shoes (a New Balance running shoe) versus the popular toning shoes. The second study evaluated muscle activation when walking in regular athletic shoes compared to toning shoes. For the exercise response study, researchers recruited 12 physically active female volunteers, ages 19 to 24 years. All study subjects completed a dozen five-minute exercise trials in which they walked on a treadmill for five minutes wearing each type of shoe. The shoe order was randomized as the subjects were asked to walk at 3.0 mph with a 0% grade hill; 3.5 mph/0% grade; and at 3.5 mph/5.0% grade. Meanwhile researchers monitored each subject's oxygen consumption, heart rate, ratings of perceived exertion (RPE) and caloric expenditure. To measure muscle activation, researchers recruited a second group of 12 physically active female volunteers, ages 21 to 27 years, who performed a similar battery of five-minute treadmill trials (as explained above) rotating shoes at random. Researchers used electromyography (a.k.a. EMG) to record muscle activity in six muscle areas: gastrocnemius (calf), rectus femoris (quads), biceps femoris (hamstrings), gluteus maximus (buttocks), erector spinae (back), and rectus abdominis (abs), as subjects walked in each of the four pairs of shoes. As a baseline for EMG analysis, maximum voluntary isometric contractions (MVIC) on all muscles were also performed using manual muscle techniques prior to testing.

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