Okay, I decided to add exercise to CRON. So far, I've quite enjoyed it but am only at a couple of times a week. My goal was to exercise 3 or 4 times a week for at least a half hour of solid exertion.
At this point, I like the exercise but it is sometimes inconvenient and I don't have the amazing motivation I have for CRON. A few more weeks and I'm hoping that the exercise will become a habit. The endorphin high is certainly worth the exertion.