Associate Director, Amy Rauworth

Fitness trends come and go, but determining if you should invest your hard-earned dollars into the latest trend takes some investigation and thought. Common sense should always win out. Just like your mother probably told you, "if it sounds too good to be true, it probably is". The latest trend, fitness shoes, incorporates a negative heel (lower than the toe) and instability to create a rocking motion. They claim to burn more calories and create an optimal "backside", which is of course a big market-driver for swim suit season. But, should you spend the estimated $100-$240 for a pair of these unusual looking shoes?

According to a recent market analysis, many people will answer yes to the previous question. In fact, the fitness shoe is projected to bring in $800 million to 1 billion in 2010! So let me help you be an informed buyer. Consumer Reports I am not, but I did try on a few different fitness shoes and have read the research.

First, who should not wear these shoes? If you tend to wear only high heels, exercise caution when trying out these shoes and if you feel pain do not use them. Prolonged high-heel use leads to shortening of the muscles and tendons in the back of your lower leg and the negative heel position could cause injury to these shortened muscles. Similarly, if you have decreased flexibility in your legs or perhaps have an issue with balance these shoes are also not for you. Individuals who are obese and/or suffer joint pain are at a greater risk for falls and have less movement control. The fitness shoes industry is directly marketing to this segment of the population, but I suggest caution. Even though a recent study suggests that over time, our bodies adjust to the movement variability associated with negative heel technology, this study was performed with college-aged students and more research is needed to test the safety of these shoes in segments of the population that are at higher risks of falls.

Secondly, do these rocker-type fitness shoes actually do what they claim? The claim is that they burn more calories, and tone and firm your glute (butt) muscles more than walking with regular shoes or walking barefoot. Americans' backsides are definitely larger than the body of research that exists on this fitness trend.

The Masai Barefoot Technology (MBT) shoe has been studied to a greater extent than the others. The MBT shoe is also the most expensive, costing around $240 a pair. According to a recent article in the Journal of Clinical Biomechanics, the MBT does in fact increase the amount of energy that an individual must expend to make the transition of step to step. The MBT shoe has a curved, soft sole that causes instability during standing and walking, and according to earlier research causes the muscles around the hip, thigh, and buttocks areas to be recruited more significantly. It is also known that balance control is a significant contributor to metabolic energy cost. The MBT shoe also weighs a little over 2 pounds each and this too may contribute to the increased energy expenditure.

The Reebok EasyTone shoes are also very popular, but have very little published research that supports its claims. One study from the University of Delaware tested only 5 women for a duration of 500 steps each. Reebok's website cites over 20,000 hours of data on hundreds of individuals to support its claims. Also on its website, is that compared to a typical foam based walking shoe, EasyTone footwear with balance ball inspired technology generated 28% more gluteus maximus muscle activation, 11% more hamstring activation, and 11% more calf activation. The EasyTone is much lighter than the MBT and incorporates "balanced pods" through which air travels through to create an unstable surface much like the feeling you may experience if you have ever run on the dry sand area of a beach.

The Skecher Shape-Ups video ad on YouTube goes as far as to suggest that the shoes will make you fitter, healthier, and happier. And, of course, the line you always hear is that you get all of this without even stepping into a gym. The Skecher website suggests that the Shape-Ups burn more calories, tone muscles, improve posture, and reduce joint stress. As with all of these lines of fitness shoes, they suggest only wearing the shoes for short periods to begin with and to gradually build your tolerance. The video also describes stretches that should be done, which is very important if you do choose to wear any of these types of shoes. The Shape-Ups are newer to the market, but they have Joe Montana as their spokesperson.

Beyond the typical tennis shoe options are the Earth Shoes and FitFlops. These brands utilize similar technologies, but offer them in sandal varieties. The Earth Shoes advertise their 3.7-degree incline, their anatomic arch support, and BioFoam™ Cushioning. The one study presented on its website compares the use of the Earth Shoe in a 10,000 Steps-a-Day walking program. The study admits that any walking program will provide positive changes on overall health, but states that wearing Earth footwear provides a more favorable impact than non-negative-heeled footwear. FitFlops website also provides their research done by The Centre for Human Performance at London South Bank University (LSBU). This research also claims an increase in leg, calf, and gluteal muscle activity, improved posture, and improved muscle tone. Additionally, the company suggests that their sandals simulate aspects of barefoot walking, but with more muscle load. The website goes even further and reports testimonials that FitFlop sandal wearers have reported relief from plantar fasciitis, heel spurs, chronic back pain, sciatica, osteoarthritis, RLS (restless leg syndrome), scoliosis and degenerative disc disease.

My bottom line (no pun intended) is to ask the question, "Do we really need to increase muscle recruitment and cause situations where we are constantly off-balance during activities of daily living to burn a few extra calories?" My answer, is no. The long-term use of these shoes is also under question. We know that women who wear heels the majority of the time can actually alter their physiology, so what will long-term use of negative heel technology do to our bodies? In the end it is your choice. If this fitness fad encourages you to get out and walk more, it could be beneficial to your health. But why not just grab the tennis shoes in your closet and get out there with a friend? Be active every day and I guarantee your bottom half will be better for it!

For comments and feedback, please feel free to contact Amy Rauworth at amyr@lakeshore.org