Muscle-Toning Shoes

Muscle-Toning Walking Shoes

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You may notice that some of your patients are wearing funny-looking workout shoes and have developed a peculiar, shortened gait. Or, patients might ask about some brands of walking shoes that purportedly tighten up the calves and butt without working out at the gym. In either case, the shoes in question are known as “muscle-toning shoes” and are marketed with names such as EasyTone, Shape-ups, and Curves.

In a growing trend, shoes like the EasyTone (Reebok®), Shape-ups (Skechers®), and Curves (Curves®, Inc) are marketed with claims that they can help wearers tighten and shape their lower-body muscles and perhaps even lose some weight. TV and radio ads suggest that these shoes, which are geared primarily toward women, make the gym obsolete.

How Do They Work?

In general, these shoes are designed to roll the foot and body into an unfamiliar walking position that stretches the Achilles tendon, thus firming the calf muscles and tightening the buttocks. Although the designs vary, the shoes generally have 1 of 2 designs. The EasyTone places ‘balance pods’ at either end of the shoe designed to simulate walking on sand. As you walk, air fills the balance pod in the toe; as the step pressure moves forward, air fills the pod in the heel. As air passes from one balance pod to the other, the sensation is one of walking on sand—which requires more work and muscle engagement than walking on pavement. Reebok estimates that this unusual gait increases gluteal muscle activation by 28%, in addition to stimulating hamstring and calf muscles by 11%.

Instead of the balance pods, the Shape-ups and the Curves walking shoes have a thick rocker sole—a natural curve along the long axis of the shoe that allows the foot to roll through each foot strike. As you step forward in these shoes, your heel sinks as you step and rolls forward as your weight shifts, which causes you to push off with your toes. Essentially, you’re moving forward without moving your foot. This causes a natural instability with every step. According to the shoes’ manufacturers, this instability causes you to work harder to maintain your balance, with an associated 11% to 41% increase in muscle activity in the legs, glutes, and calves.

The estimates of increased muscle tone are based on small industry funded studies and it remains to be seen whether more muscle engagement continues over time or stops once the walker becomes accustomed to the shoe. These shoes also have their share of healthcare skeptics who believe that these shoes don’t provide much benefit over traditional pairs and are not appropriate for everyone.

According to Boston podiatrist Edward Carver, DPM, reasonably fit folks will likely do fine in these shoes as long as they are worn for walking only and for short periods of time. He cautions, however, that these shoes should not be worn by patients who have excessive pronation or supination. And “because the footbed of these shoes is soft and deep it provides very little support for the joints…therefore, some patients are likely to complain of pain in the ankle, knees, and hips.”

Dr. Carver advises that patients who choose to wear these shoes do warm-ups and muscle stretches before walking in the shoes, and limit wear time to 25 to 30 minutes over the initial few weeks. This will decrease the possibility of muscle cramping and overuse. He goes on to recommend that anyone who experiences joint pain should stop wearing the shoes.

The bottom line? At more than $100/pair, these shoes are expensive. Data suggest that they do provide a muscular workout and perhaps even some weight loss—at least over the short-term. However, they cannot double as all-purpose athletic shoes and are not appropriate for everyone.

What You Can Tell Patients About Muscle-toning Shoes

Stability: People with balance issues, a leg length discrepancy of ½” or more, or experience vertigo should consider other options. These shoes may not offer good traction control when exposed to wet or icy conditions.

Excessive Pronation: If your ankles and feet roll in a lot, you’re asking for trouble. This type of shoe can cause more stress on your feet, knees, and hips and could complicate physiologic issues.

Heavy Lifting: If you lift heavy objects on a regular basis, the natural instability of rocker sole shoes will make work more difficult and increase your chance of injury.

These are NOT workout shoes! Muscle-toning shoes are made to help you walk in a straight line. Any side-to-side movement should be avoided. Do not wear them for aerobics, running, or weight training.

Pregnant? Don’t wear these shoes. Many pregnant women have altered their gait to compensate for a heavy middle; these shoes can thrust them off-balance and cause falls.

Jill Shuman, MS, ELS
Published on July 20, 2010