
ok, maybe sometimes.
I put on a 30 pound pack w/camelback and go trail/mountain running.
My current runs around Seattle are Tiger Mountain and Mt. Si, which is 4 miles of switchbacks in steep terrain, one way. Gets you to your max heart rate fast and stays there. It's not easy, but very fulfilling as far as workouts go for me becuase of the scenery and the need to reach the top keeps me moving.