Mine always do, and today something possessed me to shorten my stirrups by two holes, and suprisingly it didn't hurt any more than usual. I trail ride mostly, so I'll drop my feet out of the stirrups when the going is easy. I know some people who have padded stirrups that swivel or some such, and they swear by them. Although their stirrups are not proper length, so I'd be curious to know how they really work. I've noticed the more I ride the better it gets, and those summers where I only rode a few times I was reluctant to ride again because it hurt so much. I think the best excersize would be to ride through it, making sure to stretch them out or take little breaks would probably help, too.