Jet Lag: What Causes It? What's Best for Travelling East or West?

Introduction Before we talk jet lag we’ll talk briefly about our circadian rhythm.  Circa = Around, Dian (comes from Diem) = Day. It gets its name because research has proven that our circadian rhythm is actually longer than 24 hours……. So its called our ‘Around a day’ rhythm.  Ever heard the phrase ‘a night owl?’ Or ‘I’m a morning person?’…… well, unsurprisingly it’s because everybody has a slightly different pattern of circadian rhythm. Some are naturally programmed to stay up later and wake up later (night owls), and some go to bed earlier and wake up early (morning people).   Jet lag is when our normal circadian rhythm (part of our internal body clock) and the new local time are no longer synchronised with each other. When we travelled long distances by boat, train etc. it was impossible for us to zip through time zones very quickly, therefore, our circadian rhythm had more time to adapt…..once the jet engine reduced travel time significantly, it brought with it ‘Jet Lag’.  Causes of Jet Lag This rhythm can be affected by factors from both (internally) inside and (externally) outside of the body, and one of its functions is that it determines when you want to be awake, and when you want to be asleep.   The internal factors are determined by activity in the specific parts of the brain vital for triggering the release of hormones.  External factors such as light influence those parts of the brain, effecting the internal body clock. Melatonin for example, is a hormone produced by the brain during darkness and inhibited by light.  So when the natural light level starts to drop….. the amount of melatonin released starts to rise. Melatonin is like the starting pistol to signal our brain that it’s dark and to start the process of getting ready for sleep. When light starts to increase, the amount of melatonin is reduced and the process of waking up begins.  As we said before, the momentum of the body clock takes time to change and is slow to adapt. It apparently takes approximately one day for every hour time difference. So if its a 5 hour time difference, you should expect it to take about 5 days to get synchronised. Symptoms Of Jet Lag There are lots of symptoms of jet lag. Feeling fatigues and inability to sleep are the most common symptoms. In addition a traveller could experience a wide range of other physical and emotional symptoms such as; - Intermittent periods of fatigue - Difficulty in sleeping at the appropriate time - Irritability and mood disturbances, poor concentration - Lowered motivation, subjective fatigue above the norm - Decreased mental and physical performance in the “new” daytime - Potentially poor physical performance. - Headaches  - Disorientation - Poor appetite, gastrointestinal upsets. Minimising Jet Lag Prior To Departure In the days prior to departing, we may be able to make a phase shift of two to three hours, over the two to three days prior to a long-haul flight. It’s a balancing act, making sure you don’t cause too much of a negative influence on your last few days before your trip.  If you’re an athlete, and you’re going to try to start adjusting their body clock before departure, this should not be done to the detriment of overall sleep. It’s difficult to change our body clock by just changing the sleep/wake cycle, so this technique may really only offer a small advantage at the point of destination.  It may be possible to phase shift two to three hours prior to our departure. Attempting to make further adjustments generally disrupts our sleep. Tips When You're On The Plane Hydration Dehydration increases risk of upper respiratory infection. Drinking often, using saline sprays, eye drops or air humidifiers if you’re really keen can all help keep you hydrated.  DVT The prevention of DVT and wearing compression stockings should be recommended for most individuals. This strategy should be combined with optimal hydration, regular walking and stretching. The use of heparin injections should be recommended for those at risk of DVT due to a musculoskeletal injury or in cases of a family or personal history of DVT. Melatonin Melatonin can be useful but the timing of its administration is critical.Get that wrong and it could have a detrimental effect.  Sleep Unfortunately the length of time we sleep on the plane doesn’t effect jet lag at the other end of the journey, but it certainly won’t do us any harm in our adjustment to the new time zone. If we are planning a morning arrival, try to sleep in the hours just prior to landing. If, however, an evening arrival is planned, try to sleep early in the flight. Adapting To Jet Lag On Arrival This can depend on which direction you’ve travelled. Going eastwards, symptoms are more pronounced and adaptation is longer compared to travelling in a westward direction.  If you’re arriving after eastward travel getting yourself out in the late afternoon can be beneficial for sun light exposure.  Wearing dark glasses through the morning can minimise the level of light exposure. It may be beneficial to sleep in for the first couple of days (to minimise light exposure) as eastward travel naturally makes it very difficult to wake up in the morning.  Travelling West For a flight westwards it’s important to remain active during the daytime and avoid long naps. Napping can “anchor” the body clock to the home time zone and should be avoided. Easier said than done!!  Light exercise can be beneficial, stimulating our mind and body, and perhaps relieve any other jet lag symptoms.  Being socially activity can have a similar effect, helping us adapt to the local time can help synchronisation to the local time zone, supporting the readjustment of our circadian rhythms. It’s ok to get to bed one to two hours earlier than normal according to local time. Conversely, waking up may occur earlier than normal in the new time zone.  The changes in sleep-wake cycles are transient and normal sleeping patterns tend to be restored before the circadian rhythm does. General Recommendations (Summary) While one may choose to try and make a management plan which is specific to the team’s destination, there are some general concepts which should be applied to all team travel. To minimise the effects of jet lag and travel fatigue, a team should: Try to adopt the local time as soon as possible. Stay awake during the day, even if you are very tired and try to get some natural sunlight at optimal times. Exposure to bright light is the best method of resetting circadian rhythms. Exposure to bright light in the morning will advance the body clock while exposure in the late evening will promote a delay. Exercise may act to re-synchronise the body clock but is likely to be more effective for inducing a phase delay than for an advance. A high-protein diet can promote stimulation in the morning, while a high-carbohydrate diet can promote sleepiness in the evening. If your trip is short, and only travelling through two or three time zones, you may choose to behave as if on home time throughout to minimise the need for adaptation on the return home.   Physical and Mental Performance From a sports performance perspective, during the period when the body clock is adjusting to the new time zone, the athlete may experience reduced physical or mental performance.  Ideally during this adaptation period (and especially over the over the first two to three days following arrival), light exercise rather than strenuous training or competitive matches is advisable.  The rationale here is to try to reduce the risk of injury due to impaired motor skills or poor decision making caused by jet lag.   Well I hope this helps you when you’re jetting around the world! Please do share this episode with a couple of friends or family members, review, like and subscribe if you haven’t already. We look forward to hearing from you all….. we’ve had some really nice messages, and some ideas from our community for future content too. Find us on socials…. Links are in the description, and we’ll see you in the next episode! Bye now.    https://youtube.com/channel/UCQXAka99a6MdZexeEJaMZbA https://m.facebook.com/elevatehealthuk https://www.elevatehealthuk.com/ https://instagram.com/elevate_healthuk?utm_medium=copy_link   ABOUT THE HOST TOM BUTTERFIELD I have always been interested in sports, unfortunately injuries and poor training decisions curtailed my dream of...