By Jordana Bieze Foster
The research on toning shoes presented early this month at the annual meeting of the American College of Sports Medicine in San Francisco didn’t add much support for controversial claims that the rocker-bottom footwear promotes muscle activation and energy expenditure. But the presenters did point out more subtle benefits of toning shoes that manufacturers might find are more acceptable to the Federal Trade Commission.
“I’m going to try to save Skechers,” announced Brian B. Parr, PhD, associate professor of exercise and sports science at the University of South Carolina Aiken, while presenting one of six studies that were part of an ACSM Thematic Poster session on toning footwear.
Less than two weeks earlier, toning shoe manufacturer Skechers had agreed to a multimillion-dollar settlement in response to charges of deceptive advertising; Reebok settled a similar suit last fall (see “Skechers settles for $50 million but stands by advertising claims”).
The findings presented at the poster session suggested that rather than making the wearer’s muscles work harder, if anything, rocker-bottom or unstable shoes are actually easier to walk in than conventional shoes. Research from Alabama State University in Montgomery, for example, found that electromyographic activity differed significantly between toning shoes and conventional walking shoes for only one of five muscles measured—and in that case, biceps femoris activity was greater in the conventional shoe than the toning shoe. Investigators at the University of Tennessee in Knoxville found greater frontal plane ankle muscle involvement during walking in a rocker-bottom shoe than a control shoe, but also found that sagittal plane ankle moments were reduced in the unstable shoe.
It’s probably not surprising, then, that another University of Tennessee study found no difference between rocker-bottom shoes and conventional shoes with regard to heart rate or oxygen consumption while standing or walking. Parr and colleagues found that in obese individuals (mean body mass index, 33) toning shoes were associated with higher levels of oxygen consumption and energy expenditure during treadmill walking than conventional shoes, but those differences, while statistically significant, were likely too small to be clinically significant.
Parr noted, however, that his study participants took 200 more steps and reported intake of 800 fewer calories per day during one week of toning-shoe wear compared to one week of conventional shoe wear.
“The shoes themselves don’t seem to do much, but they seem to put people into this frame of mind where they do things that are healthier,” Parr said. “So if someone gets these shoes, maybe they’ll be excited and start walking more, and maybe they’ll also start changing what they eat.”
Such changes may be related to footwear comfort. The University of Tennessee researchers also found that many of their study participants were much more comfortable in the rocker-bottom shoes than the conventional shoes, said Dixie L. Thompson, PhD, professor and head of the Department of Kinesiology, Recreation, and Sport Studies at the University of Tennessee.
“If people are wearing more comfortable shoes, they’re more likely to be active,” Thompson said. “So I think there’s really something to be looked at here.”
The findings could even put a positive spin on anecdotal reports of injuries associated with toning shoes, which might be a function of previously sedentary people becoming motivated to increase their activity levels while wearing the shoes, Parr suggested.
“Unfortunately,” he joked, “Skechers didn’t call me before they agreed to the settlement.”
LeVeau BF, Beckham KL, Davis KM, et al. EMG comparison of five muscles while walking in fitness shoes and conventional walking shoes. Presented at 59th annual meeting of the American College of Sports Medicine, San Francisco, June 2012.
Paquette M, Zhang S, Milner C, et al. An improved unstable shoe alters ground reaction forces and ankle biomechanics. Presented at 59th annual meeting of the American College of Sports Medicine, San Francisco, June 2012.
Thompson DL, Brady A, Frederick G. Physiological responses to wearing rocker bottom shoes. Presented at 59th annual meeting of the American College of Sports Medicine, San Francisco, June 2012.
Parr BB, Huff KE, Masters HE, Kilday ZV. Effect of toning shoes on exercise energy expenditure, walking behavior, and energy intake. Presented at 59th annual meeting of the American College of Sports Medicine, San Francisco, June 2012.