Replying to all of you who think I am a troll. I would run 7 miles every day at work too. I guess that isn't going to convince anyone that I am healthy either. As long as you can sleep when you are off it is no problem. Pilot for 20 years, worked shifts for the 10 years prior. I have called in sick for myself once a year, and I don't work if I am sick. My cholesterol could be lower but no health issues otherwise. I fly with a lot of guys younger than me who eat M&Ms the whole flight, go out for crap food and never work out, and find they have no energy.