Wanted to do my tempo run this morning, time carefully planned out. Sadly, a deer culling at my local metropark ended that plan.
Oh well, such is life. Probably safer to do it on a treadmill anyway. Sadly tho, it's not the intensity level that's going to be the issue on the treadmill, but the boredom.
Still, like I've said, the treadmill is great for developing two things in running: a sense of pace and mental toughness.
Pace because it does not let you cheat. It will not let up.
Mental toughness because of the aforementioned boredom. It's terribly easy to run through the woods without a sense of time. In comparison to running on a treadmill, it's a vacation.