Artificial Hills

Have been feeling fine since Weds (no more anti-inlams for me!) but didn't want to risk a road run today just in case so it was back to the treadmill for an interval hill run. I wonder how similar treadmill hills are to real hills? I guess it's similar to the general road/treadmill running relationship, i.e. they both work in different ways so whenever you switch from one to the other it always seems hard!! Acting on some insane impulse that I cannot begin to explain when I was doing some abs and weights after my run I put in a couple of sets of lunges. I can't remember the last time I did lunges, needless to say by the time I got back up the hill to my office I could barely make it up the stairs!! What was I thinking?