Love 'em or loathe 'em - I have learnt not to avoid them and in fact include various 'gradients' in all my runs now. Just recently I have been visiting my nemesis - an energy sapping off road run across local farmland/fields complete with my dreaded grassy hill (which I run twice!) Parts of the fields can be quite boggy after rain, so if the hill doesn't get you, the muddy bits do! Today I ran after work and the hill I have dreaded for so long and me, are starting to get along a bit better...😮🙂. I still find it tough but (dare I say) I kind of enjoy it too now.
I am sure that including it regularly in my running week is helping with my pace when I'm back on the roads. My legs are definately stronger ...so top tip...get running up those hills, folk! 🙂