Well i'm also a runner and I train with this intensity for each daily run:
My hard days I will either do sprints (5x400m) or (3x800m) in an almost all out effort. Or I will do a 2 mile tempo run at a very fast 95% pace.
Medium intensity days are simple about 3-5 strides consisting of 200m in length at 85% effort.
Hope this helps!