I got a good article from my gym on toning shoes. It was in a newsletter so I can't link to it, but I'll post it here for anyone who is interested.
CN - they are not worth it and (although not yet proven) may even be bad for your health.
Now for the article:
With all the buzz about toning shoes, the American Council on Exercise (ACE) decided it was time to put their claims to the test. The following was extracted from their recent report on the effectiveness of toning 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.
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 What they fail to mention, however, is that these studies are not peer-reviewed, and most are of questionable design.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.”
To test the effectiveness of the shoes and evaluate their claims, a pair of studies was conducted, 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.
The Results
Across the board, none of the toning shoes showed statistically significant increases in either exercise response or muscle activation during any of the treadmill trials. There is simply no evidence to support the claims that these shoes will help wearers exercise more intensely, burn more calories or improve muscle strength and tone.
The bottom line? Don’t buy these shoes because of the claim that they will tone your butt more or burn more calories. A major concern of the researchers is that extended wear of these toning shoes may alter the walking gait mechanics of wearers and, in some cases, potentially cause problems for those who may already be at risk for lower-extremity issues. But to evaluate that will require another longer-term study.
And although the toning shoes don’t deliver on their advertised claims, there may be potential that these shoes could improve wearer’s balance over time, but that too will require a long-term training study. Additionally, these shoes may be encouraging a fair number of people who probably wouldn’t put on a normal pair of walking shoes and go out and walk, to do so because they think they’re getting some super toning effect.
