Wow! The exercise sounds like a great outlet, BG.
I get busy with chores when the anger comes, as there is energy in it that I don't have often. It also gets me off the electronics.
Our yard has several acres with gardens and one day I just sort of powered through and it was pretty neat to see, four hours and a lot of sweat later, it looked pretty good!
Or one day I washed all the windows I could reach and it was pretty neat. Not so much as all of your miles, but still a good outlet for the energy that anger brings.
I don't know about others, and I find the anger is awful, but it's better than the tears. There's feul in it somehow.
The only thing that stays the same, is change. -M. Etheridge