Treadmill is different than actual ground. If you don't put incline on it, when you start running on real ground you'll feel out of place. I get my heartbeat up better on a treadmill because I can Guage my speed, also might have to do with the climate control. But I like running on trails, love the scenary.
I wake up at 4 every morning to go to work. There's no way I am getting up any earlier than that. lol.
