Athletes and Team members leaving from South Africa to Tokyo will have to cross 7 time zones during their journey. Travel fatigue and jet lag are amongst the various challenges they may need to navigate. Be prepared – read more.

Jet Lag

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What is jet lag and what causes it?

It is a temporary sleep disorder that may affect those who travel frequently across 2-3 time zones. It occurs when the body’s internal clock/ circadian rhythm is out of sync with the destination time zone. Cues such as light exposure and eating times of the destination time zone may contribute to jet lag and lead to travel fatigue. Some symptoms of jet lag are daytime fatigue, difficulty concentrating, sleep disruption, gastrointestinal disturbances. These effects can lead to travel fatigue and an increased risk of illness and usually affects one’s athletic performance.

What resolves jet lag?

Jet lag is usually resolved with a good night’s rest according to the destination’s time zone. This includes re-synchronisation of the human circadian systems to new light-dark cycles of destination. Although most peripheral rhythms re-synchronise at different rates, internal desynchronization progressively disappears as all rhythms become synchronised to the local time, which is why athletes feel worse on day 2-4 compared to day 1 of arrival. The circadian system needs to advance with East travel as is the case with Tokyo, Japan. Eastward travel is generally tougher than Westward travel as the endogenous circadian rhythm has a ±25 hour period making it harder to advance than delay your circadian system.

Resynchronisation takes approximately one day for travel to the East which means a comprehensive travel management plan to minimise impact on performance is needed. For return to the West, it takes half a day for resynchronisation.

What steps can I take to resolve or prevent jet lag?


Light exposure/ avoidance, sleep, exercise, nutrition, melatonin, stimulants and sedatives. Their application and timing of the above are dependent on the number of time zones crossed, travel direction, length of stay and individual chronotype.

 Illness prevention may seem unrelated to travel fatigue and jet lag management, but if an athlete contracts illness both conditions may be aggravated. So take measures to stay heathy!

 Practical tips to follow:

  1. Pre-travel
    1. Protect sleep by minimizing the accumulation of sleep debt and bank sleep.
    2. Determine your core body temperature minimum as most interventions are based on this (this isn’t always practical so don’t worry if you dn’t do this)
    3. With individuals with known gastrointestinal disturbances, the team doctor may consider using probiotics.
  2. During travel
    1. Protect your sleep maximising rest and sleep during a “sleep window” corresponding to night-time of destination. Sedative usage should be individualised and only taken on doctor’s order.
    2. Implement illness prevention strategies and avoid touching areas known to carry microorganisms. Take care to sanitise areas of contact before and after use.
  3. Post-travel
    1. Plan light exposure and/or avoidance around your core body temperature minimum, depending on timing for East travel.
    2. Try to schedule training sessions to coincide with light exposure. Sunlight is the best option however indoor training with the aid of artificial light may be a better alternative when it is dark outside. Keep training intensity low for the first few days, building up to higher intensity and skill- specific training.
    3. Melatonin has both chrono biotic and hypnotic properties. Team doctors should be cautious and preferably use known products.
    4. Protect sleep by following a sleep schedule and adjust sleep timings as the body Clock adjusts to new time zones. Make use of sleep hygiene interventions and supplement night-time sleep with a daytime nap. Sedatives should be short acting and only used upon doctor’s order. Athletes should be aware of recent updates with WADA regulations for all pharmacological interventions.
    5. Implement illness prevention strategies.
    6. Caffeine may be used to increase alertness and manage daytime fatigue.
    7. Meal timing and meal composition may help to reduce jet lag symptoms. Consume protein rich meals to help with alertness and carbohydrate rich meals to induce drowsiness.

 It is recommended that practitioners focus first on the easier to implement interventions that help treat the symptoms of jet lag such as protecting sleep, and prevention of illness, before employing more difficult interventions such as accelerating the adjustment of the circadian system to the new time zone.


Janse van Rensburg, D., Fowler, P. and Racinais, S., 2020. Practical tips to manage travel fatigue and jet lag in athletes. British Journal of Sports Medicine, pp.bjsports-2020-103163.

 Image taken from: Janse van Rensburg, D., Fowler, P. and Racinais, S., 2020. Practical tips to manage travel fatigue and jet lag in athletes. British Journal of Sports Medicine, pp.bjsports-2020-103163.