Entrepreneurs who have to travel abroad on business may be harming their prospects - because they don't know how to deal with jet lag.

Sleep experts reckon that mind over matter just doesn't work. Instead, you have to get the balance right between light exposure, food, drink and exercise - or you'll be stuck in what's been labelled the 'Zzzz Zone'.

Dr Chris Idzikowksi has been called in by British Airways to work out the best way of dealing with jet lag. He's put together an interactive jet lag adviser.

He said:

"If you travel on business from London to Hong Kong you will hit your maximum sleepiness between the hours of 11am and 1pm Hong Kong time.

"If you plan a business meeting around this time it is the equivalent of planning a meeting between 3am and 5am at home."