The "Jet-Lag": effects and management

Preparing for jet lag helps prevent what is called "desynchronization syndrome", which causes a decline in motor and athletic ability that can have a significant impact on athletic performance.

“Jet lag disturbs athlete or any traveler by causing symptoms of desynchronization, in particular a sleep disorder. You must therefore prepare for this shift at home and manage it during air transport in order to save time. "

What is "Jet Lag"?

Travelers crossing time zones encounter a pattern of light and dark, and their endogenous circadian rhythms adapt to the new external time signal until the two "time systems" synchronize.

The "Jet Lag" is a syndrome appearing following certain long air trips due to the desynchronization between the circadian rhythms.

The symptoms are generally:

• General fatigue

• Difficulty in initiating sleep maintenance

• Daytime sleepiness, decreased alertness

• Loss of concentration

• Irritability, anorexia, gastrointestinal problems

• Cognitive and motor performance in particular athleticism may be impaired

These symptoms can be more or less severe, depending on:

• The number of time zones crossed (from a 4 hour shift, the risk increases with the hours of shift)

• Flight characteristics: number of hours, departure and arrival times, direction (best supported if traveling west)

• Personal factors of the athlete: age, fatigue, habits (the more the athlete has suffered from lags, the better he adapts), stress related to travel, dehydration ...

• From the moment: they can be more severe between the 2nd and the 4th day

How to avoid the Jet-Lag?

In case of a brief stay, not exceeding 3 days, do not change anything in your habits.

You have to try to organize your trip as best as possible:

• Arrival time: personally, in the case of a long trip, I prefer to arrive at the end of the day after a trip during which I easily deprive myself of sleep (movies, meals, ...)

• If possible, arrive a few days before to stay there at least the number of days corresponding to the number of time zones crossed before the competition. So in theory, if you cross 5 time zones, you have to be there 5 days before! Not always easy !

The days before the trip, in theory we could start to shift the rhythms. But the athlete is exposed to a disruption of his training, and this only plays a role over 1 or 2 hours of lag.

In this case, we can start to get closer to the times of the destination: gradually delay the times of going to bed and getting up, the times of meals and the times of training, submitting to daylight or strong ambient light , …

But once again, performance is a little affected by this manipulation which is not really worth the trouble.

During the trip

My principle is simple: immediately take the schedule so the rhythm of the country of arrival.

• Set your watch immediately to the time of the country of arrival,

• Country of arrival = day: try not to sleep (enjoy the films available)

• If country of arrival = night: try to sleep, even if it means going without meals. Don't forget your neck pillow, headphones and blindfold!

• Air in the cabin is dry: drink to avoid dehydration. Avoid alcohol and caffeine.

• To reduce muscle stiffness cramps and avoid circulatory problems, do muscle contractions, walk in the cabin +++, wear compression stockings.

• Take stopovers into account: keep the same principle!

What consequences in case of "chronic Jet Lag"?

Repeated long-term disruption of the synchronization between the two time systems impairs physiological and psychological health and induces stress.

In airplanes, in cabin crew, salivary cortisol levels after repeated exposure to jet lag were significantly higher than after short-haul flights.

The higher levels of cortisol were associated with cognitive deficits that depended on non-semantic stimuli.

Studies show that significant prolonged elevations in cortisol produce reduction in temporal lobe volume and deficits in spatial learning and memory. These cognitive deficits appeared after five years of exposure to high levels of cortisol.

Make it simple and Have a nice trip !

Biblio:

Kwangwook Cho (Department of Anatomy, MRC Centre for Synaptic Plasticity, Medical School, University of Bristol, Bristol, BS8 1TD, UK)

Dr. Patrick Bacquaert (Institut Régional de Biologie et de

Médecine du Sport - Nord pas de Calais)