Future running partner.
Where do you do your hill workouts? I like my hills to be about 1/4 mile long with a flat area on top and a flat area at the bottom, because I run hard up and stride down, then jog in between at the top and bottom. The best I have found is a 160m hill near my house with a semi flat area at the top and bottom. It has a 10 to 15 degree grade.