There's no doubt that the time zones can really wallop you. Most guys find what works for them, and every trip, there's a discussion on individual "sleep recipes".
"I sleep for 3 hours, then work out. One beer after dinner and I'll be light's out."
"If it's night time at home base, I try to sleep. Otherwise, I stay active."
That sort of thing. Everyone has their own routine. In London, at least, for the typical AM arrival, 2 hours rack time, activity, then some pub grub and a pint will knock me out.
I have petitioned management for the
ultimate WB long haul trip... One that would be incredibly gentle on the body. Right now, we launch for deep South America at 2000 or so. 30+ hours layover, and it's all-nighter home, 0500 arrival. It hurts, which is why Sao Paulo and similar go junior.
How about launching those trips at 0800? You arrive early evening, about 3 hours or so of time zone difference. Sleep normally. Launch for home at 0800 local. Overfly the incredible Amazon basin in daylight, and maintain a normal body clock.
I guarantee such a trip would instantly go senior over Tokyo and Europe.