I usually do all my long runs on pavement. The only non pavement is either some kind of football fields, or track. But I don't want to run around the track for 90 minutes.
I found out recently a park, but it's all along a hill, and pretty small. So basically I will have to go up and down at least 15 times.
The problem is that because it's very steep, I'm afraid that going down 15 times for 3 minutes on such a steep hill might be worse for the knees than running a pavement.
What do you think ? Is it worse ?