Recovery from jetlag can take as long as a day for every time zone crossed.

Recovery from jetlag can take as long as a day for every time zone crossed. So if you’re flying east-west for your holiday or on business, it is likely to mean a few days of feeling tired or even unwell.
    Jetlag is the disruption of the body’s natural cycle and some factors make it worse. The artificial atmosphere inside a plane can affect the body in a number of ways and add to the effects of jetlag. Exercising before flights helps to offset the effects on the body of reduced air pressure and aerobic exercise afterwards helps to re-oxygenate it. Drink plenty of water. Children may need more. Drinking carrot juice before flying overcomes oxygen deficiency.
    Eat light, frequent meals. Heavy meals slow down the blood circulation, which can lead to dizziness and fainting. For two weeks before you fly, eat plenty of food containing vitamins A and E: they will build up your immune system and help to keep you fit. Sleep as much as you can before the flight and on it. On board, wear earplugs and eye pads because darkness stimulates secretion of the hormones that enhance sleep.
    Avoid alcohol, which restricts the brain’s oxygen intake. Like tea and coffee, alcohol increases the dehydration effect of flying. If you need to drink to relax, bear in mind that the cabin environment intensifies the effect of alcohol.
    Wear loose, comfortable, warm clothes and limber up during flight. Sitting down for several hours slows down the circulation, leading to local stiffness, cramps and dizziness. Re-adjust to local time as soon as you can. Bright light helps the body stay alert, so if you are going somewhere sunny, stay outside.
    Do not smoke before or during the flight since smoking decreases the blood oxygen level. If you need to calm your nerves, try aromatherapy oils which have a sedative effect. Consult your doctor before flying if you are on medication. The effects of some drugs are strengthened at high altitudes and some may produce side effects.