For the 1st time last weekend, I tried Shape-Ups all day without a problem - it's not as if you'll be walking non-stop for 8 hours - you walk a little, stop & stand in line, walk some more, etc. While you're standing, you can rock on them & stretch your calves. I definitely noticed significantly decreased back pain (& my legs did not get worn out) from wearing the Shape-Ups this last time, compared to previous Disney visits - this was one of the reasons I bought the Shape-ups after reading reviews of them. While the Shape-Ups are about $100 everyplace, if you have a Kohl's charge, use the coupons you get in the mail--sometimes for as much as 30% off, plus 10% for using your Kohl's charge. For kids, just make sure they wear really comfortable sneakers with socks, not flip-flops or sandals. Have a blast -