Flying across time zones to run a marathon is one of the better decisions you can make as a runner. Flying across time zones and getting your preparation wrong is one of the more effective ways to waste a good race. Jet lag affects performance in measurable ways. When your body clock is out of step with local time, it disrupts temperature regulation, glycogen storage, and muscle strength. None of those are optional when you are asking your body to run 26.2 miles.
The good news is that jet lag is manageable. It just requires some planning.
The Short Cut
- Jet lag disrupts the biological rhythms that govern temperature regulation, energy storage, and muscle strength, all of which affect marathon performance.
- Flying east is harder to adapt to than flying west. The body finds it easier to delay its clock than to advance it.
- Light exposure, meal timing, and sleep schedule are what reset the body clock. Not medication alone.
- Allow one day of recovery per time zone crossed where possible. If that is not practical, prioritise the pre-travel preparation.
Start Before You Leave
The body's internal clock responds to light, food timing, and sleep schedule. All three can be shifted gradually in the days before travel to reduce the adjustment needed at the other end.
Direction matters. Flying east (UK to Asia, for example) means your body needs to believe the day starts earlier. Start going to bed and waking up an hour earlier each day for three or four days before your flight, and get outside into bright natural light as soon as you wake up. Flying west, UK to the USA, is easier for most people. Stay up and sleep a little later each night, and get outdoor light in the late afternoon.
Melatonin can help accelerate the adjustment, but check with a doctor before using it. For eastward travel, a low dose taken in the local evening at your destination's time zone can bring sleep onset forward. For westward travel, it is sometimes used in the morning to extend sleep if you are waking too early.
On the Plane
Change your watch and phone to the destination time zone the moment you sit down, and eat and sleep according to that clock. Drink water consistently. Aircraft cabins are drier than most people realise, and dehydration makes jet lag measurably worse. Avoid alcohol. It feels as though it helps sleep but it fragments sleep architecture, which is the opposite of what you need.
Modern GPS watches from most manufacturers now include jet lag guidance features. If yours does, input your flight details a few days before departure and it will prompt you with specific nudges about when to seek light, when to avoid it, and when to nap. These tools are worth using, though they are no substitute for the basics above.
At Your Destination
Light is what resets the body clock fastest. After an eastward flight, get into morning sunlight without sunglasses as early as possible and avoid bright screens and lights in the late afternoon, since you want your body to start winding down at the right local time. After a westward flight, do the reverse: time outdoors in the late afternoon and evening pushes melatonin production later, so you are not falling asleep at 3am local time.
Do not stay in the hotel. A 20 to 30 minute easy run between 2pm and 4pm local time raises core temperature, which is a wakefulness signal, and tells your body it is daytime and time to be functional. It is not about fitness at this point. It is a biological reset.
Keep meals simple and on the local schedule from day one. Your digestive system has its own internal clock, and feeding it at local mealtimes helps synchronise it faster than almost anything else. Race weekend is not the time for dietary experimentation regardless, so familiar, simple food serves double duty here.
How Much Time Do You Need?
The rule of thumb is one day per time zone crossed. Five time zones means arriving at least five days before the race. That is not always practical, so if you cannot arrive that early, weight the pre-travel preparation more heavily. Shifting your schedule before departure and anchoring quickly to local time on arrival together achieve most of what a longer stay would otherwise provide.
Related reading: Jet lag management is one piece of the destination marathon preparation puzzle. Running Your First International Marathon covers the full picture: kit, food, course reconnaissance, race morning logistics, and the post-race plan. For how to manage nutrition on a disrupted sleep and meal schedule in the days before the race, The Golden Rules of Glycogen and Race Morning Fuel cover the fuelling specifics. The races where time zone management matters most: Tokyo Marathon (9 hours ahead of UK), Sydney Marathon (10 to 11 hours), and Chicago Marathon (6 hours behind UK).
The Extra Mile
- Reilly, T., Waterhouse, J., Burke, L. M., & Alonso, J. M. (2007). Nutrition for travel. Journal of Sports Sciences, 25(Suppl 1), S125–S134.
- Waterhouse, J., Reilly, T., Atkinson, G., & Edwards, B. (2007). Jet lag: trends and coping strategies. The Lancet, 369(9567), 1117–1129.
- Samuels, C. H. (2012). Jet lag and travel fatigue: a comprehensive management plan for sport medicine physicians and high-performance support teams. Clinical Journal of Sport Medicine, 22(3), 268–273.
- Leatherwood, W. E., & Dragoo, J. L. (2013). Effect of airline travel on performance: a review of the literature. British Journal of Sports Medicine, 47(9), 561–567.
- Fowler, P., Duffield, R., & Vaile, J. (2015). Effects of simulated domestic and international air travel on sleep, performance and recovery for team sports. Scandinavian Journal of Medicine & Science in Sports, 25(3), 441–451.
The information in this article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before changing your training or medical protocols.