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In his new blog, FIFPro’s Health and Safety Advisor, Dr. Vincent Gouttebarge, discusses playing football at altitude. ‘There is a close relationship between a substantial acclimatisation period and a good football performance.’

By dr. Vincent Gouttebarge, PhD

As acknowledged in a previous blog on heat conditions at FIFPro.org (internet link), professional football players have been exponentially on the move across countries or continents, being exposed

within and between seasons to different environmental conditions. Especially in international competitions in Central and South America (for example Copa Libertadores, Copa Sudamericana and FIFA World Cup qualifiers), short periods of training and games at moderate to high altitude have often been the subject of discussion among different international governing bodies within professional football.

Background

In 2007, FIFA introduced a ban on international matches at a height of more than 2,500 metres (8,200 ft) above sea level. A year later, FIFA suspended this ban after a protest letter by CONMEBOL (football’s governing body in South America). Since then, footballers are allowed to play at a higher altitude than 2,500 metres. FIFA recommends an acclimatisation period of at least three days when playing at an altitude of 1,500 metres or above.

With regard to the matches both national and international played in Central and South America at altitudes reaching up to 3,600 metres (La Paz, Bolivia), the question arises whether the health and safety of the players are at stake, especially for the international players used to playing at a lower altitude or at sea level when at their clubs.

Body responses to altitude

When ascending to a higher altitude, the human body has to deal with…:

  • decreased atmospheric pressure;
  • thinner, colder and drier air;
  • stronger ultraviolet rays from the sun.

The decrease in atmospheric pressure is of course the most important consequence of higher altitude: less oxygen is available to use for normal regulation mechanisms, daily-life activities or sport performances (Wilmore 2007). Consequently, the body has to work harder at high altitude than at sea level to achieve a particular task because of the decreased availability of oxygen. It is well accepted that altitudes of 1,500 metres or more might have the following relevant physiological implications for the body (Wilmore 2007):

  • increased respiratory i.e. breathing frequency to bring a larger volume of air i.e. oxygen to the lungs;
  • slightly limited oxygen transport through the blood (for instance to the muscles when playing football) because less haemoglobin is available to carry the oxygen;
  • substantial reduction of oxygen transfer from the blood to working organs and thus oxygen uptake impaired;
  • increased heart rate to increase the volume of blood transported to working organs.

Altitude sickness

With regard to the combination of the lack of oxygen at altitude and the high energetic load on players during professional football, unpleasant i.e. adverse health effects might occur, especially when acclimatisation periods are not long enough.

Acute mountain sickness: headache, dizziness, nausea and poor sleep, these mild symptoms often clearing up in a day or two
High-altitude pulmonary oedema: breathing difficulty, chest tightness, cough and fatigue
High-altitude cerebral oedema: confusion, lack of coordination, stumbling and poor balance

Importance of acclimatization

In order to prevent too severe body reactions and altitude sickness as a consequence of altitude, periods of acclimatisation are strongly recommended ranging from a few days for an altitude of 1,500 metres to a few weeks for an altitude above 2,000 metres. The process of acclimatisation enables the body to deal with the decrease in oxygen. How long this process should last depends on the altitude attained and the duration spent at this altitude, ranging between a few days and several weeks (Wilmore 2007). One thing is sure: getting to altitude too rapidly and staying there always lead to altitude sickness.

The acclimatisation process is also essential in order to perform optimally at altitude. Training at a higher altitude for two weeks or more before any competition has been acknowledged as a potential strategy (Muza 2010; Wilmore 2007). However, because of the immediate negative responses of the body, intensity of the training during the first two weeks after arrival at altitude should be limited to 60-70 % of the intensity applied at sea level (Gore 2008; Wilmore 2007). Then, the intensity of the training might be gradually increased over the next two weeks.

When such a long acclimatisation period is not feasible, an alternative is to compete within one day after arrival at altitude as the negative body responses do not have time to occur (Gore 2008; Muza 2010).

Performances in professional football at altitude

Apart from the occurrence of (serious) altitude sickness, training and competing at altitude might influence the football game itself. When professional footballers train and compete at altitude, their physical fitness in particular is strongly influenced by their body’s ability to cope with the decrease in oxygen availability.

Because football match results depend largely on the excellence of players’ endurance and their (physical) ability to repeat high intensity sprints during the whole match, the logical assumption is that altitude might be an environmental condition that influences the level of performance and the outcomes of matches. In 2013, Nassis and colleagues studied the effects of altitude on football performances during the World Cup 2010 in South Africa. The authors showed that playing matches at an altitude of 1,200 m or higher had a negative effect on the endurance capacity: players covered less distance (- 3.1 %) during matches at higher altitude than during matches at sea level.

In 2007, 1,460 international football matches in South America (Argentina, Bolivia, Brazil, Chile, Columbia, Ecuador, Paraguay, Peru, Uruguay and Venezuela) from the FIFA database (1900-2004) were analysed by McSharry and colleagues. These analyses showed that altitude had a significant negative impact on the physiological performance of teams from lower altitudes because of the lack of proper acclimatisation. Teams from higher altitudes had a greater probability of winning than teams from lower altitude, scoring more goals and conceding less.

In 2011, Williams and colleagues compared the outcomes of South American international matches between the same teams but played at different altitudes within the same country, enabling control for travel distance. While moving to a lower altitude did not affect performances, travelling to a higher altitude was shown to have negative effects on match outcomes. Especially the teams competing in Quito (Ecuador; 2,800 m) and La Paz (Bolivia; 3,600 m) performed poorly. Similar results were found by Fraude (2011) and McSharry (2007) who compared the success of teams living at different altitudes (sea level, low altitude and moderate altitude) during the World Cup. Teams from low and moderate altitude had a higher winning percentage (more than twice) than the teams living at sea level.

Key points

  • Exposure to altitude leads to a reduction of oxygen uptake. To compensate the reduction of oxygen uptake, respiratory (breathing) frequency and heart rate increase.
  • When acclimatisation to altitude is insufficient, altitude sickness tends to occur, leading to symptoms such as headache, sleeping disturbance, chest tightness, fatigue, confusion and lack of coordination.
  • Good football performances at higher altitude are closely related to an acclimatisation period of two weeks or more before any competition.
  • Football national teams (South America) living at low to moderate altitude are likely to have a higher winning percentage than teams living at sea-level.
Former professional football player Dr. Vincent Gouttebarge is senior researcher at the Coronel Institute of Occupational Health from the Academic Medical Centre in Amsterda (the Netherlands), and is co-owner of Vintta, a research and consultancy unit for sports health.