This really cannot be overstated. When I was in college I always made it a point to schedule a fitness class of some kind in my credit load, most of the time it was just a credit to show up at the gym regularly. It was a great way to overcome my laziness and get regular exercise.

It was one of the most important lessons I learned at the time because I had gone through a year or so of no real exercise and when I started again everything became so much easier.