The advisors and the advice

The calculators and advice have been written by Dr C Idzikowski PhD a well known UK sleep specialist (a founding officer of the British Sleep Society and subsequently Chairman, and also the founding Chairman of the Royal Society of Medicine's Sleep and its disorders forum, now the Sleep Medicine Section) and author.

Apart from the Epworth Sleepiness Scale the calculators and advice have been written specifically for this site. The Epworth is well known and validated, but may not be completely accurate in this setting. Nevertheless if you score high then you should consider seeing a physician (print out the results).

The other calculators and advice provide a 'guide' - they are not definitive. When a calculator outputs its advice it does so on a 'best guess' basis determined by general population characteristics and the current published knowledge in the research literature. It has to be recognized that people vary and are different - so you may find that you have to experiment and go through a period of trial and error in order to get the best out of your lights.

Jet lag advisor
Jet lag is caused mainly by a mismatch between the time of the brain’s biological clock and local real time. The internal 24 hour clock consists of about 10,000 nerve cells deep in the brain and it tries to co-ordinate and synchronize the rest of the body to 24 hour (light and dark) rhythms. This clock normally runs slowly and dawn light usually speeds it up. There are other synchronizers, for example the brain’s melatonin (which is secreted by the pineal gland), sleep, exercise, food, social interaction, and others) but light is the most important. The main principal behind the advisor is that dawn light speeds up the clock, so if the clock needs to be sped up to match a new time-zone, then the advisor recommends exposure to light. If it is better for the clock to slow down, then the advice indicates avoidance of light. In addition to this, research also shows that evening or particularly light at night slows the clock down, so this too is taken into account. The advisor assumes that most people are equally sensitive to light at night and at dawn; but, since individuals vary, experimentation may be required to get exactly the right amount and timing of light exposure or avoidance.

Meals It is often best to travel on an empty or near-empty stomach, and adopt mealtimes at the new time-zone as soon as possible.

Exercise Good general health promotes good sleep. Exercising during the day at a new time zone can help adjustment.

Duration of stay The advice should accelerate adaptation to a new time zone. However, it is usually best for short trips of two-three days to remain at one's home time zone.

FAQs  These are still being developed - if you want to ask a question or make a comment please press here.