listen to the scrap man, he knows his stuff. as a person who's had a seroius injury ( compartment syndrome ) and went under the knife i cant stress how importent it is to always prepare yourself and don't do to much to soon. if you could run 10 miles a year ago it doesn't mean you can now, even if you have the will power to do it, it doesn't mean your ankles, shines, knees, hips or back can. take it easy and progress slowly