I was interested in these shoes for a variety of reasons. I lift weights and do cardio regularly, but I'm a big guy who's always looking for another way to burn off a little more fat or build a little more muscle. I've also been hearing a lot lately about how our shoes are making most of us walk on our heels instead of the balls of our feet, and was curious if these might help with that. Well, after a little over a month of wearing these, I am very satisfied with them. They have really started to get me used to walking more on the balls of my feet and less on the heels, and they seem to have helped me burn some extra calories and build some muscle. The couple of times when I've been in situations that require a lot of walking or standing and have not been able to wear these shoes, I've found myself wishing that I had been able too. They just make that big of a difference.