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Posts Tagged ‘High-Altitude’

High Altitude Football Teams Have Significant Advantage Over Lowland Teams

Posted by addisethiopia / አዲስ ኢትዮጵያ on October 9, 2013

ከባሕር በላይ የ 2400 ሜትር ከፍታ ባላት አዲስ አበባችን የኢትዮጵያ እግርኳስ ብሔራዊ ቡድን የየትኛውንም የአፍሪቃ ቡድን የመቅጣት ተፈጥሯዊ ዕድል አለው። ስለሆነም፡ አሰልጣኞችና የሚመለከታቸው ሁሉ ይህን ገፀበረከት በመጠቀም አስፈላጊውን የታክቲክና ስትራቴጂ እርምጃ ሊወስዱ ይገባቸዋል። በመጪው እሁድ ከናይጀሪያ ጋር በሚካሄደው ግጥሚያ የኛ ተጫዋቾች በመከላከሉ ላይ ብዙ በማተኮር አልፎ አልፎ ሹልክ እያሉ በማጥቃት ተቀናቃኞቹን በቀላሉ ብዙ እንዲሮጡ ቶሎም እንዲደክሙ ማድረግ ይቻላል ብዬ እገምታለሁ።

High Altitude Football Teams Have Significant Advantage Over Lowland Teams

FlagCrossMFootball teams from high altitude countries have a significant advantage when playing at both low and high altitudes, finds a study in this week’s Christmas issue of the BMJ.

In contrast, lowland teams are unable to acclimatise to high altitude, reducing physiological performance.

At altitude, lack of oxygen (hypoxia), cold and dehydration can lead to breathlessness, headaches, nausea, dizziness and fatigue, and possibly altitude sickness. Activities such as football can make symptoms worse, preventing players from performing at full capacity.

In May 2007, football’s governing body, the Federation of International Football Associations (FIFA), banned international matches from being played at more than 2500 m above sea level. So Patrick McSharry, a research fellow at the University of Oxford, set out to assess the effect of altitude on match results and physiological performance of a large and diverse sample of professional footballers.

He analysed the scores and results of 1,460 international football matches played at different altitudes in 10 countries in South America spanning over 100 years.

Four variables were used to calculate the effect of altitude and to control for differences in team ability (probability of a win, goals scored and conceded, and altitude difference between home and away team venues).

Altitude difference had a significant negative impact on performance. High altitude teams scored more and conceded fewer goals as altitude difference increased. Each additional 1,000m of altitude difference increased the goal difference by about half of a goal.

For example, in the case of two teams from the same altitude, the probability of the home team winning is 0.537. This rises to 0.825 for an altitude difference of 3,695m (such as high altitude Bolivia versus a sea level opponent Brazil) and falls to 0.213 when the altitude difference is -3,695m (Brazil versus Bolivia).

The surprising result is that the high altitude teams also had an advantage when playing at low altitude, so benefiting from a significant advantage over their low altitude opponents at all locations.

There is still some debate over the best strategy for low altitude teams to employ when playing at high altitude to deal with this disadvantage.

He suggests that assessing individual susceptibility to altitude illness would facilitate team selection.

Source: BMJ-British Medical Journal

Altitude in Football – How Much Difference Does it Make?

Though the debate surrounding altitude in football and sport in general has been around for a number of years, it was on April 1st 2009 that the debate was really thrown up into the air (the only pun in this piece, I promise) and into the public eye. On this date, Bolivia hosted Argentina in a World Cup qualifying match in La Paz, a city that lies approximately 3600 metres above sea level. The Bolivians came up with one of the biggest shock results in international footballing history, hammering nailed on qualifiers Argentina 6-1. The visitors looked uncharacteristically slow and lethargic, but were also uncomfortable in possession. Question the FIFA world rankings as much as one may please, but when the world number 6 ranked side at the time loses 6-1 to the ranked 58 side in such a manner, many felt this was the final straw.

However, it was two years prior that FIFA first tried to address the issue of altitude in the game. In 2007, FIFA temporarily banned all international matches that were being played at above 2,500m, but less than a year later after severe pressure from CONMEBOL the ban was repealed. In a FIFA statement from 2008 they claimed Anything between 500m and 2000m was termed “low altitude”; and at low altitudes, and at low altitudes it was claimed “minor impairment of aerobic performance becomes detectable”. Beyond this, it is unclear where the figure of 2,500m being the acceptable limit was forged, and why it was this particular altitude that was the cut off limit. It is widely known that travelling to a higher altitude without the appropriate time to acclimatise has detrimental effects on cardiovascular activities (to the extent of mountain sickness, even below altitudes of 4000m), but beyond this, higher altitudes and the respective change in atmospheric pressure can result in a change in the flight path of a football. The reason it took this long to address is relatively simple – many felt that altitude could just be part of a “home advantage”. The days of compact, dank away dressing rooms are well within memory and it is only this season that sizes of pitches have been standardised. The philosophy of complete neutrality, or in an economists terms “all other things being equal”, is actually a relatively new idea – but nevertheless an idea that has to be addressed in the modern game.

Certain difficulties arise in data collection. Simply put, the number of nations with any footballing integrity that also play at altitude is slim. More specifically, it’s three. All based in South America, the majority of studies focus on matches at Quito, Ecuador (2800m), Bogot, Colombia (2550m) and La Paz, Bolivia (3600m). This small sample size of countries over this mythical 2500m boundary provides an obstacle in data collection but luckily, all three have long standing footballing traditions – meaning many matches have taken place at all three venues. Though there have been complaints at lower levels of altitude (Denmark and Netherlands blamed poor performance on playing at Johannesburg, 1750m), many studies have scrapped the idea that altitudes below 2000m have a large effect on performance. So for the sake of argument, we shall look only at the three nations in South America.

What is immediately interesting is that is appears there is no linear correlation in the data. It isn’t a case of ‘the higher you go, the harder it gets’ – but that only after certain altitudes does the game become much harder.


These graphs (taken from – show an interesting finding. The dark blue represents games below 2000m and the lighter grey above 2000m. It clearly shows that whilst Bolivia and Ecuador gain is almost all areas of the game from playing at home (3600m and 2800m respectively), the lower of the three national stadiums (Colombia at 2550m) actually fared worse at home than when travelling. Furthermore, this data has been collected over many decades of play, so despite the small sample size cannot be considered an anomaly. The analysis shows that travelling teams have success in Colombia, but just 250m further up in Ecuador the winning percentage from the home team increases by 25 to 30%. Further up in La Paz, the winning percentage increase becomes 45%. Perhaps this indicates that there should be a cut off for matches at altitude, but what remains unclear is how much of this advantage comes from the altitude change and how much from other factors traditionally associated with the ‘home advantage’. The variables that naturally vary from nation to nation (humidity, atmospheric pressure, air quality, temperature etc) certainly have to factor into this advantage too.

Some studies have also, interestingly, made a connection between travelling to lower altitudes and this also having a detrimental effect on play. These studies, however, were conducted during the early part of the collective research into this subject, and failed to take into account footballing quality of the nations at higher altitudes and also the difference in quality of nations over time. Figures as erratic as a 27% less chance of winning when travelling to lower altitudes have been published – but fail to take in other basic variables; namely, that the three historically most successful teams on the continent all play at lower altitudes. If it wasn’t a complicated enough issue through battling the immeasurable variables and the limited data pool, it definitely becomes complicated once one has to sift through poor research. Any high school science or economics student will tell you that correlation does not equal causation. Reputed sports scientists working on data to be considered by FIFA, apparently, would not tell you this.

But beyond the poor quality of some studies, many are of course convincing and reputable in their argument – and it is said studies that provide some interesting findings. Initially, certain studies have claimed that whilst the outcome of the match does not change very often, the margin of winning does. In the current league table World Cup Qualifying format that South America has, this is obviously an issue that needs to be addressed. Furthermore, a different study into altitude speculates that more than a third of the goals scored in these three high altitude locations are scored in the final 15 minutes, and are overwhelmingly in favour of the home team. This could show that visiting players are able to perform at close to their optimal level, but not for a full 90 minute match.

To conclude, whether the evidence is anecdotal or statistical, the evidence is there that altitude does affect the game. However, at this time it remains unclear what specific altitudes should be deemed acceptable, but there does seem to be a presence of a certain height where players can still perform. Thus, policy implementation becomes difficult. There is a clear advantage of playing in La Paz at 3600m, and this is almost universally accepted by the scientific community looking into this matter. But below this height, the statistics often contradict each other and a ban on a single nation’s participation in their national stadium would be widely protested. Certain in game solutions have not been considered yet, however. Obviously acclimatisation is largely impractical due to the small time frame teams have to play international matches – but a system of a drinks break and short rest at the 22.5min/67.5min periods (as has been implemented in the French Ligue 1 to combat temperature) may well have a positive effect on the game’s outcome and standard over the full 90 minutes. This, at the present moment, is pure speculation on my behalf and has not been tested. What is clear is that this is an issue, and a particularly complicated one at that – no decision will come without protest, but the data shows that something definitely should be done.



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Ethiopian High-Altitude Natives Are Different

Posted by addisethiopia / አዲስ ኢትዮጵያ on November 28, 2008


Ethiopian high-altitude natives respond to hypobaric hypoxia differently than Andean (South America) or Tibetan highlanders.


In Ethiopia, a third successful pattern of human adaptation to high-altitude hypoxia is amazingly puzzling. In contrast with both the Andean “classic” (erythrocytosis with arterial hypoxemia) and the more recently identified Tibetan (normal venous hemoglobin concentration with arterial hypoxemia) patterns, the Ethiopian adaptation is very unique.


A field survey of 236 Ethiopian native residents at 3,530 m (11,650 feet), 14–86 years of age, without evidence of iron deficiency, hemoglobinopathy, or chronic inflammation, found an average hemoglobin concentration of 15.9 and 15.0 g/dl for males and females, respectively, and an average oxygen saturation of hemoglobin of 95.3%. Thus, Ethiopian highlanders maintain venous hemoglobin concentrations and arterial oxygen saturation within the ranges of sea level populations, despite the unavoidable, universal decrease in the ambient oxygen tension at high altitude.


The demonstration in the past 20 years that the “Andean man” model of high-altitude human adaptation does not generalize to natives of the Tibetan Plateau changed scientific understanding of human adaptation to high-altitude hypoxia. Comparisons of Andean and Tibetan high-altitude natives residing at the same altitudes [usually in the range of 3,500–4,000 m, or 11,600–13,200 feet, where partial pressure of inspired oxygen (PIO2) is 64–60% that of sea level] have revealed quantitative differences in traits associated classically with offsetting ambient hypobaric hypoxia.


For example, a hematocrit or hemoglobin concentration elevated over normal sea level values was long considered a hallmark of lifelong adaptation to high-altitude hypoxia; however, studies of Tibetans have demonstrated that it is not a necessary response to ambient hypoxia or arterial hypoxemia.


The population contrast extends to other traits as well: a comparative study reported that Andean high-altitude natives at 4,000 m had hemoglobin concentration and oxygen saturation of hemoglobin more than 1 standard deviation higher than Tibetans at the same altitude. The mean hemoglobin concentration of Tibetans was not elevated above sea level values despite very low oxygen saturation. The third major high-altitude population, natives of the Semien Plateau of Ethiopia, has not been studied for these traits.


These findings suggest there are three patterns of adaptation to high-altitude hypoxia among indigenous populations . Learning why the three populations differ will require two lines of future investigation. One is understanding the biological mechanisms and the underlying genetics that allow successful high-altitude adaptation with quantitatively different suites of traits for oxygen sensing, response, and delivery. The other is understanding the evolutionary processes that produced these patterns to explain how and why several successful human adaptations to high altitude evolved.


Posted in Ethiopia, Ethnicity, Genetics & Anthropology | Tagged: , , , , , , , | Leave a Comment »

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