One of the topics that will be discussed at the IOC World Conference in Monaco from 16–18 March 2017 is 'Protecting the health and performance of the traveling athlete'.
International travel is an unavoidable part of elite athletes' competitive careers, and as such, its effects on their health and performance have become an important component of the planning that goes into their training and preparation for competition. Prof Christa Janse van Rensburg, Head of the Section Sports Medicine at the University of Pretoria (UP), offers her view on some of the challenges that need to be considered and overcome in order to ensure that peak performance is achieved under foreign conditions.
Challenges faced with international travel
International travel is part of the lifestyle of any elite athlete. Unfortunately, it is accompanied by physiological disturbances that lead to a complicated set of physical symptoms. Factors that come into play include environmental changes, disruption of the biological clock, and resulting from travel fatigue and/or jet lag. The combination of the demands of travel and the disruption of the circadian rhythms may enhance fatigue and negative mood states. It may also increase the athlete's susceptibility to illness, as was shown by Prof Martin Schwellnus and his team in a cohort of rugby players participating in the Super Rugby Tournament.
Environmental challenges may affect athletes travelling distances as short as 500 kilometres, and include changes in:
- season (Northern versus Southern hemisphere),
- atmospheric pollution,
- strains of pathogenic organisms,
- diet regimens, and
- drinking water.
The athlete's biological clock will be influenced differently depending on the direction of travel. Flying west is usually easier, as it lengthens the day and implies that the body clock needs to be delayed. Flying east, however, shortens the day and therefore the body clock needs to be advanced, which is more problematic. For every time zone travelled (15 degrees) the biological clock has to move one hour. To adapt and resynchronise, it is advised that one should allow one day of rest for every time zone crossed. Physiological adaptations occur, but the sleep-wake cycle recovers faster than other physiological cycles such as heart rate variability (HRV). HRV is an indication of the health of the heart. In general, the higher the variability, the better. Too little variation implies chronic stress or insufficient functioning in different levels of autonomic controlled systems. From previous research, it appears that there is a lag in the HRV response to changes in time zone and climate. Studies are currently being undertaken in the Section Sports Medicine at UP(Grant, Jansen van Rensburg) to further determine the impact that this has on the performance of athletes.
Travel fatigue must be differentiated from jet lag, although the two can exist together. Travel fatigue is associated with any long journey, irrespective of the mode of transport or the direction of travel. Jet lag results from long-distance, trans-meridian travel, and the severity depends on the direction of the flight and the number of time zones crossed.
Measures to counter the effects of travel fatigue and jet lag include non-pharmacologic and pharmacologic treatment. During travel, it is advised to drink lots of water and abstain from alcohol use. Comfortable clothing, compression socks and moving around frequently will enhance blood circulation and prevent swelling of the legs as well as possible clotting. Schedule travel during sleeping hours at the destination, and set your watch to the destination time. Do not share drinking bottles or shake hands with fellow passengers. On arrival, the body clock can be advanced or delayed with the help of bright light therapy. Natural light is better and morning exposure will advance the clock while evening exposure will delay the clock. It also seems that the type of food consumed is not as important as the timing of meals. Melatonin has been used widely to assist with sleep initiation, but also to shift the physiological phases. Use of exogenous melatonin products has been proven effective and safe; however, it may be difficult to attain a product of acceptable quality. Short-acting sleeping tablets have also been used to assist athletes that struggle to fall asleep at their destination.
In conclusion, travel poses a big problem for anyone who travels frequently. It affects not only an individual's physiological well-being, but can also make one more susceptible to disease.