Today, I worked out, which while some people might think "how can you take time from learning?" I would say that anything that you can do to help you think better, learn better, and be healthier, which allows you to do more mitzvot, is a good thing, as long as it doesn't become the reason for your being. Meaning, a workout should be a park of your life, not your whole life. Also, you will notice, after a good workout that whatever mood you were in before, becomes improved, and you are in a better mood now.
On that note, I would like to share with you a clip from the Lazer Beams website, that shows you how you can do a simple upper body workout from your desk chair.
The armchair commando's workout part 1