the idea is it basically shortens your running stride and quickens your kayden. things hurt less. runs generally love it, just that is not for everybody. gerri: and using these reports? what do you make of them? >> at th i see this with peopleo want to run all of my miles you have to build up your muscles so they are strong enough to do this. your form changes. your stride shortens a little bit. you have to get used to running that way. gerri: so yo you're using diffet muscles really? >> that is right. they get more work. gerri: if you're doing this the right way, i would think her feet would just kill you. >> he had to build up a tolerance to doing this. but there are lots of people who swear by this. it should be done gradually and it is not for everybody. it may not be for you. gerri: you are a big runner. give us advice on shoes that may or may not be good for you. >> they see a shoe, this looks great. i think going to place where they know about running shoes, something that feels good to you, everything is accessible online but going to a running store you know what you are