Interval Training

Sooooo I am trying to figure out this whole speed interval training on the treadmill thing. I like things to be as simple as possible, so I really don't want to keep an eye on the time and press the up or down button on the speed. I just want to touch a button that does it for me.

The treadmill at the school gym has an interval training button. But I have no idea what level to use. I think it would help if I knew what the highest level was. I tried playing around with the levels yesterday. After falling asleep at the beginning pace of level 1 and level 5, I jumped up to level 15.

I guess, I don't have a full understanding of speed intervals. I was picturing a difference of like 2-4 minutes from the slow pace to the fast pace. But level 15 went from a 18 minute mile to a 7 minute mile. I was sure I was going to be one of those people who flew of the treadmill in an embarrassing accident.

Somehow I managed to release one finger off the hand rails and slow the pace to a 9 minute mile. In hind site, 9 minutes is not "fast" but it was all I was prepared for.