(It should be noted that ACE is a nonprofit that certifies a lot of fitness pros who would be out of a job if we could all get fit without working out. ACE says it commissioned the study but that it was independently conducted. John Porcari, one of the study's authors, says the team consulted with ACE on its design but that data were collected, analyzed and written up with no involvement by the group.)
Researchers conducted two studies, with two different groups of 12 physically active female volunteers in the 19-27 age range. One had the women doing a dozen five-minute stints in which they walked on a treadmill set at different grades wearing each kind of toning shoe, as well as a control pair of regular running sneakers. Researchers measured the study participants' oxygen consumption, heart rate, perceived exertion and calorie burn. A similarly conducted study measured activity in six different back and lower-body muscle groups.
You can see all the charts detailing their findings in ACE's report. The gist: "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," ACE says. "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."