I got these so I would have a flip-flop with better arch support, traction and wear than a $2 Old N*vy pair.  I wore these every day for about 6 months straight.  When I went to dig out my summer clothes, tons of them were loose around the waist and rear-- I hadn't made any changes to my habits, and the scale read the exact same thing it had the previous summer, so the only thing I can think of is these sandals did "as promised" by toning things up a bit. They've held up nicely, too. Just barely a few unnoticeable cracks after over a year of rough wear and they've been thrown into a washer a few times as well.  They're a bit easier to adapt to than the Sk*chers line of toning shoes, and more lightweight.