Quote: wakeytrin "Would have thought with jet lag etc they would be coming back fatigued.'"
Not always the case. They will have flown Business Class where they would have a full length seat/bed which is more conducive to sleep than your average peasant class seat down the back of the aircraft, plus they would have had advice/info from sports scientists etc about how to combat jet-lag, eg. when to eat, sleep drink etc.
So it may not be a major factor.