It's been a couple of weeks since I've done anything in the way of exercise. Two Weeks! I feel like crud, too. I've been sick with a severe sinus infection and the antibiotics I'm taking are putting me on edge. My pharmacist sister-in-law says I'm that way because I'm going through endorphin withdrawal because I haven't done anything in more than two weeks. So, my body's craving endorphins....so, I'm addicted to exercise? My wife demands that I ride my bike on the trainer for an hour. Sounds like a good plan.