I fly to Japan at least once a year, which is a 13 or 14 hour difference from where I am - it is difficult for jetlag to get any worse, and you get it in both directions. Normally they say you get it worse one way than the other, but that's because you're usually going later one way and earlier the other... not really the case when going literally halfway around the world. You end up with a 36 hour "day" in both directions, plus the fatigue of a 12-14 hour flight itself.
I've had 13 years of doing this to try to figure out a way to avoid it, and nothing really works 100%. I agree with those that say forcing yourself to stay up on the first day does help, though it can be very hard. It helps to plan something special on that day. Sometimes we go stay with my in-laws for the first few days and they just sit around and watch TV
and that makes it pretty much impossible to stay awake. If I can, I try to get them to at least go out with us to a restaurant where I know we'll be eating for hours - that gives me something to physically do. But ideally, I try to schedule some exciting event on that first night.
I also try to stay up *late* on that first day, as late as possible. Reason is I know I'm going to wake up in the middle of the night otherwise, no matter how tired I am. My body still knows it's "supposed" to be morning, so after 2-3 hours of sleep, I'm back up. I can sometimes get around that - or at least make that wakeup time a less ridiculous hour - by staying up until 1 or 2 AM
. By then I am completely trashed, of course, but I've still had a full day and the next day should be more comfortable.
My internal clock doesn't reset immediately so I still go 4 or 5 days when I'll feel totally fine through the day until about 5PM, then I crash. I just stay out and put myself in situations where I physically can't sleep. I know some people go back to their hotels to "rest" periodically and that's a bad idea if you're jetlagged. After a while, the feeling of tiredness does pass and I'm fine until I get back to my hotel (or in-laws' house) later at night. This is much worse if I haven't had the "hell day" on the first day and stayed up really late. If you give in on that first day, your clock will be really screwed up.
When I come home I go through all the same things because by then, I've just gotten used to Japan time and now I need to reset again. It can be even harder because now I've just got routine stuff to keep me awake, so I do end up falling asleep at odd hours (sometimes while in the middle of typing on my computer!) for weeks sometimes.
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!