I took two weeks off of yoga to study for finals. I did Rodney Yee's Strength Building yesterday and again today, agh! My arms feel like they're about to fall off. Two weeks makes a huge difference.
I have a friend at work who does all those 90 day program workouts, and she said she's going to let me use her ChaLean Extreme videos. They look good, and they're only supposed to be 30-45 minute workouts (I'll have to wait to do her P90X over the summer, because there's no way I could fit their 90 minute workouts into the school year). I'll let you know how ChaLean is once I get going on it.