Travel direction- another Jet lag at fault

Feeling exhausted and sluggish after a long flight? Possibly, it’s jet lag. This condition is not actually associated to the length of flight, but in fact to the transmeridian (east-west) distance travelled. Jet lag is a physical state resulting from changes in a person’s accustomed body’s circadian rhythm or the sleep-wake cycle. It is the disorienting effect caused by jumping time zones faster than the body can physically adapt to the changes.

The course of travel affects the severity of jet lag. Travellers going to north or south in a similar time zone typically bear the least anxiety because the time of day has no difference as in the place where the flight originated. These travellers may also feel slight symptoms as a result from confinement in an airplane or from differences in climate, culture, and diet at the destination. Travellers flying to the east, noticeably experience the most problems because they "lose" time. The mean performance is decreased more and the peak performance deteriorates dramatically. Aside from that, flights to the east would require passengers to stay up more than one full night to adjust to the local time zone. Travellers flying west "gain" time and can cope more easily than eastward travellers. In flying westward the normal cycle is momentarily prolonged and body rhythms can extend in the same manner.

Individuals who can adjust readily to modifications in their routine seem less vulnerable to jet lag. However those who are confined to a fixed routine are frequently the worst victims.