It may sound like a cliché but there are several actions that you can take to make any long haul flight safer and more comfortable. Whether you are travelling business class on flights to Sydney or economy to South America, the principle is the same on how to stay well.
Often people think that they should start their holiday as they mean to go on and the party starts at the airport, often involving alcohol.
Many airlines will refuse to take you if you have been drinking too much but even if you are drinking in moderation, remember that alcohol dehydrates the body and you will feel fitter and fresher after your flight if you have not been drinking at all.
Take regular exercise while on board – Ok there is not much space, I agree, but small regular walks around the aircraft just to stretch your legs or even small exercises from the comfort of your chair.
Try to get some sleep too, however tempting the on board films are, or you will arrive in your destination needing some serious sleep. If you are a light sleeper take some noise cancelling head phones or earplugs to block out the noise and consider investing in a good pillow and an eye mask to make it as comfortable as you can.