Hopping in and out of planes is exercise enough, you say. But that's not the kind of exercise that will condition your heart, make your reflexes and joints more fluid, keep the sugar levels or keep you from swinging from one mood to another!

Nor is it the kind of exercise that will make you euphoric after a good cardiovascular session. You need to counteract the effects of jet lag, artificial air in pressurized aircraft cabins and sky fatigue.