Lol I tried one hoping for to get that magical 6 pack a few years ago when I was a wee bit bigger - good for a laugh, but in reality they just don't compare in any way, shape or form to real physical exercise!
I use one for when my back gives me jip.:d
But I wondered on the TENS thingie it has a control for massage, could I use this on my muscles after a run?:d