Topic of Interest

In Motion

A Publication of the American Orthopaedic Society for Sports Medicine
sPorT plus physical therapy, LLC

Article 4: Toning Shoes May Not Be as Beneficial as Advertised
By Monte Hunter, MD, and Jeff Dowling, PhD

Fit shoes, or toning shoes, have become the latest fitness rage. With marketing claims to burn more calories, improve endurance, tone leg muscles, reduce joint pain, and improve posture, these shoes have become increasingly popular and visible over the last two to three years. They represent the fastest growing segment of the shoe industry and are expected to create $1.5 billion in revenue in 2011.

One fit shoe style was inspired by the Masai people who are known for their perfect posture and lack of low back pain. The founder of Masai Barefoot Technology (MBT) observed that the Masai walked barefoot over soft earth and sand. The curved sole or rocker bottom of the shoe was designed to create an unstable walking base meant to mimic the natural environment of the Masai. This design is thought to strengthen muscles in the lower leg and ankle as the shoe wearer works harder to maintain balance during normal activities.

The MBT shoe is the original “fit shoe.” It originated in Switzerland in 1996, and came to North America in 2003. MBT and Skecher Shape-Ups are the most common of these shoes. The Reebok Easy Tones are similar, but are designed with pods in the forefoot and heel. The common denominator is an unstable walking base and a price tag of $100 to $250. Not all shoe companies have embraced the concept and some have thus far stayed out of this market.

Fit shoes are touted as having several benefits: stronger muscles in the legs, back, buttocks, and abdominals; improved cardiovascular endurance; reduced body fat; increased circulation; and decreased neck, back, ankle, and foot pain. These benefits are mainly supported by consumer testimonials, and celebrity endorsements. Companies have performed research studies supporting the benefits of the shoes, but many of these studies are poorly designed and not peer-reviewed.

The American Council on Exercise recently released two studies comparing the benefits of fit shoes from MBT, Skechers, and Reebok with traditional running shoes from New Balance. These studies concluded there was no evidence to support the claims that fit shoes help wearers exercise more intensely, burn more calories, or improve muscular strength or tone compared to the traditional shoes.

As of march 2011, only two randomized controlled studies exist analyzing the effects of these or similar shoes. The only claims supported by these studies are some pain reduction over time in patients with moderate osteoarthritis in the knee or low back pain.

Claims have also been made that wearing these shoes has caused injury (ankle sprains and even stress fractures) and increased knee or low back pain. There are currently no studies to support or suggest that these shoes are dangerous to wear or cause increased pain.

Fit shoes may benefit some patients with knee or low back pain, but cannot be recommended for the other touted benefits at this time.