Whoever travels far risks jet lag: fatigue, concentration problems, digestive trouble. Yet much can be done.
Adjust your sleep rhythm before departure
Heading east: sleep earlier. Heading west: later. That way the time difference is less abrupt for your body.
Choose a night flight
Choose a night flight if you can. You arrive rested and can begin the day. On arrival, do not sleep straight away if it is not sleeping time in the destination country, that worsens the jet lag.
Spend time outside
Daylight steers your melatonin production and gives your biorhythm a reset.
Immerse yourself
Immerse yourself in the local rhythm. Eat and sleep when they do. Set your watch to the arrival time zone as you board.