Everything in moderation. Sure, you can party down route, just don't over do. Occasional trip to the gym, plenty of water everyday, etc. I have been flying for nearly 6 years, 3 low-cost short haul and 3 long haul and my friends say that they haven't noticed any adverse changes, apart from my greater tollerance for booze!!! Lol!
I read about that American guy on airliners.net, fair play to him.