Makes sense to me too. Lucky I have a 75 minute spin class once a week. And lucky I have an instructor whose humor gets me through the first 45 minutes or so. Those last rounds around the "track" are so much easier! And each round I can leave a little more resistance on in the recovery phase, then add the same number of turns as we hit the "hills", so when we get to the final round I'm actually doing some work. Now I just need to find a route that will do the same. (And get my bike back from CA.)