I run 3 different runs a week. I run one tempo, a long run, and then a hill interval run. This is the run I dread til it is over, but it provides me with some of my most productive workouts. This is the hardest run of the week. I run hills and then run repeats up a steep 100 yard incline. This is my substitute for speed work. My favorite run is a long trail run and I look forward to it. The tempo run is used to evaluate fitness and progress.