Exercise on a 747
 

Walk!! Make 3 or 4 laps. I have done this on every long-haul flight, and have never had any problems.

Admittedly I have never done push-ups or jogged, but I don't in the least mind making a fool out of myself by stretching and doing squats in the aisle every so often. Some people do get funny looks on their faces, probably from envy because they are just too embarassed to do anything similar themselves :D Hey, you fly Y, you gotta do what you gotta do.. (another good reason to get an aisle seat!)

It will be interesting to see how many people think that doing a few push ups is a sign of aggression.

everyone stretches at some point on those long hauls, I don't care what cabin you are in....

But I would love to see someone doing vigorous calisthetics in the aisle or by the lavs (or in the lavs with a partner!).