Reducing Travel Fatigue and Jet Lag in Athletes

Elite and recreational athletes often travel long distances to compete. Travel and all the factors associated with it (stress, long hours of sitting, alteration of the usual diet, thermal changes, moderate hypoxia during flights, etc.) not only pose great psychological stress, but can also have certain consequences on sports performance. One of the adverse effects of travel — particularly if it's long-haul (especially when crossing more than three time zones) — is the so-called 'jet lag', that is, the alteration of circadian rhythms due to the change of time zone. Thus, although there are numerous factors that cause "acute" fatigue during travel, jet lag will be one of the main factors.

Several studies have confirmed the adverse effects that travel can have on sports performance. For example, one study evaluated performance in a repeated sprint test after simulating the effects of trips of different lengths (24-hour international, or 5-hour domestic) by placing athletes in a chamber that produced moderate hypoxia like that which occurs during an airplane. The results showed a greater deterioration in performance after the 24-hour flight, which was accompanied by a greater feeling of fatigue and a greater alteration in the quantity and quality of sleep¹. In addition, possibly due in part to factors such as stress or fatigue, travel could also have certain health consequences, and in fact a study in Rugby players showed a higher incidence of illness in the days following an international trip (>5 hours time difference) compared to weeks when they did not travel².

Strategies to avoid the negative effects of travel

We therefore see that travel, especially long-haul travel, can have negative effects on athletes, but what can we do to avoid it? Although there are many strategies that can supposedly mitigate the negative effects of travel, the scientific evidence regarding them is less than we think. For example, a review published in the prestigious British Journal of Sports Medicine tried to evaluate the effectiveness of different strategies, both pharmacological (e.g., melatonin, sedatives, stimulants) and non-pharmacological (e.g., exercise, sleep, nutrition, light) to avoid the negative effects of travel on athletes. After analysing a total of 22 studies, the authors concluded that, although there are some preliminary studies supporting the benefits of some strategies, the evidence is generally of low quality and at high risk of bias³.

We are therefore faced with a lack of consistent scientific evidence (i.e., randomized trials not biased by factors such as the placebo effect) that supports the use of strategies before, during, or after travel. Faced with this situation, a group of international experts including doctors, scientists, nutritionists and physical therapists has published a consensus article in which they have proposed some strategies to reduce the negative effects of travel, which may be useful guidance given the lack of strong scientific evidence (see summary in Table 1)⁴. In these recommendations, the authors differentiate between trips in which jet lag does not occur because they have a relatively short duration (<3 hours) and those that do produce jet lag, the latter being the ones that require greater attention. After these long-haul trips, our circadian rhythms are altered, that is, there is an asynchrony between the "peripheral" clocks (guided by factors such as light and noise) and the central clocks of the body. This asynchrony is often accompanied by numerous symptoms such as fatigue, gastrointestinal problems, drowsiness, and difficulty falling asleep at night, which can last for several days. In fact, it is estimated that it takes half a day for each time zone to recover full synchrony if traveling westward, and one day for each time zone if traveling eastward.

In the aforementioned expert consensus, the authors recommend that to avoid these problems, sleep and wakefulness signals (e.g., exposure to light, food intake, etc.) should be progressively adjusted several days before starting the trip. Thus, if you are going to make a trip to the east, which means an increase in time zone (i.e., you will have to go to bed earlier), it is advisable to expose yourself to sunlight earlier and earlier to adapt your circadian rhythms before the trip, as well as to avoid sunlight and artificial light (including the use of electronic devices) and reduce food intake in the last hours of the day. On the other hand, if you are going to make a trip to the west, you can progressively delay your bedtime. In fact, the progressive adaptation of circadian rhythms through these strategies before and during the trip itself (e.g., controlling factors such as exposure to light) has been shown to improve the amount of sleep not only during the trip but also in the following days, as well as to reduce the negative effects of jet lag^5,6. In this sense, melatonin supplementation in the days before and after the trip could also be an effective aid to avoid the effects of jet lag. ⁷. In addition, certain considerations should also be taken into account during the trip itself, such as maintaining a correct state of hydration and avoiding the intake of large meals (especially avoiding foods with a high caloric content) and drinks that make it difficult to rest, such as alcohol or caffeinated drinks. It is important to mention, however, that depending on the direction of the trip we can try to stay awake, in which case caffeine intake may be recommended. Finally, it will be advisable to avoid very long periods of inactivity, and it is advisable to move around the plane from time to time.

Table 1. Summary of some recommendations to avoid the negative effects of flights on athletes. Adapted from Janse Van Rensburg et al.⁴

Conclusions

Travel, especially if it is long-haul, can have negative consequences for athletes. The main objective before a trip should be to promote rest and hydration, trying to avoid large meals and drinks that make it difficult to sleep, such as those containing caffeine or alcohol. In addition, in the case of trips that cross several time zones, it is advisable to adapt circadian rhythms progressively even from several days before the flight, which can be achieved by modifying exposure to stimuli such as sunlight and artificial light according to the time at the destination.

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References

1. Fowler P, Duffield R, Vaile J. Effects of simulated domestic and international air travel on sleep, performance, and recovery for team sports. Scand J Med Sci Sport. 2015;25(3):441-451. doi:10.1111/sms.12227
2. Schwellnus MP, Derman WE, Jordaan E, et al. Elite athletes travelling to international destinations >5 time zone differences from their home country have a 2-3-fold increased risk of illness. Br J Sports Med. 2012;46(11):816-821. doi:10.1136/bjsports-2012-091395
3. Janse Van Rensburg DCC, Jansen Van Rensburg A, Fowler P, et al. How to manage travel fatigue and jet lag in athletes? A systematic review of interventions. Br J Sports Med. 2020;54(16):960-968. doi:10.1136/bjsports-2019-101635
4. Janse van Rensburg DC, Jansen van Rensburg A, Fowler PM, et al. Managing Travel Fatigue and Jet Lag in Athletes: A Review and Consensus Statement. Sport Med. 2021;51(10):2029-2050. doi:10.1007/s40279-021-01502-0
5. Fowler P, Duffield R, Morrow I, Roach G, Vaile J. Effects of sleep hygiene and artificial bright light interventions on recovery from simulated international air travel. Eur J Appl Physiol. 2015;115(3):541-553.
6. Fowler P, Knez W, Thornton H, et al. Sleep Hygiene and Light Exposure Can Improve Performance Following Long-Haul Air Travel. Int J Sport Physiol Perform. 2020;16(4):517-526.
7. Chan V, Wang L, Allman-farinelli M. Efficacy of Functional Foods, Beverages, and Supplements Claiming to Alleviate Air Travel Symptoms: Systematic Review and Meta-Analysis. Nutrients. 2021;13(3):961.