You don't have to climb Mt Everest to be affected by altitude. Rugby teams suffer too.
Sports fans often overlook, or dismiss what an impact high and low altitudes have on a sports teams' performances. Yet Sports Scientist Dr Ross Tucker (Health24's FitnessDoc) believes this is actually a huge factor in training and says that altitude can have a "substantial effect on a team's performance".
"Teams who are playing at a high altitude need about a week's worth of training at that altitude to get used to it - because it takes about a week for their bodies to get back to baseline levels in terms of performance," he explains.
However, Tucker points out that there is another school of thought followed by some teams: by minimising 'exposure' in other words arriving at the high altitude only hours before the game, and leaving straight afterwards, the negative impact on performance will be reduced.
Tucker does not subscribe to this, and since there have been no scientific studies to prove that this method actually works, he has science on his side.
"I think that any teams with aspirations of winning, will arrive at least a week before their games and train at the higher altitude," says Tucker.
FIFA recommends acclimatisation periods
In 2007 the Federation of International Football Associations (FIFA) banned international matches from being played at more than 2 500m above sea level. In line with the decision, an upper altitude limit was imposed for matches in FIFA competitions in which the players and match officials are not given time to acclimatise in advance.
According to FIFA, the following criteria were upheld:
- Above 2 500m: acclimatisation period of three days strongly recommended;
- Above 2 750m: mandatory acclimatisation period of one week;
- Above 3 000m: games generally not permitted except with a minimum acclimatisation period of two weeks.
And in accordance with this, it was also recommended that the same limit be introduced for international competitions organised by other football bodies.
How high altitudes affect the body
It's the drop in air pressure at high altitudes that affects athletes who are more used to playing at lower altitudes. This drop in pressure makes it difficult for the body to obtain sufficient oxygen, and it's the body's reaction to this 'thin' air that can affect how athletes perform.
Extremely high altitudes can eventually lead to hypoxia (oxygen deprivation), and cold and dehydration can lead to breathlessness, headaches nausea, dizziness and fatigue. Although, this is more applicable to places with extreme altitudes, such as on top of mountains.
While the players might not notice the drop in air pressure when getting off the airplane and walking around, they will definitely notice it when they start training, as their ability to consume oxygen is reduced by the high altitude. This will directly affect their physiological performance.
However, the body has a built-in mechanism to counter the effects of low oxygen levels, and when it senses that it's not getting the same levels of oxygen it's used to, the body begins to produce greater numbers of red blood cells which carry oxygen in the blood stream. But this is a process which cannot happen immediately, and this is why several days are needed for the body to acclimatise properly.
What the research says
According to a study in the British Medical Journal on the effects of altitude on physiological performance, a statistical analysis was carried out using the results of international football games.
For the study they analysed FIFA's extensive database of 1 460 football matches in 10 countries over a period of 100 years. And what they found backs up Tucker's claims.
In their findings the researches report that "altitude had a significant negative impact on physiological performance as revealed through the overall under-performance of low-altitude teams when playing against high-altitude teams in South America."
According to the study, the high-altitude teams scored more goals and conceded fewer with increasing altitude difference. Furthermore, they found that each additional 1 000m of altitude difference increased the goal difference by about half of a goal.
"The probability of the home team winning for two teams from the same altitude is 0.537, whereas this rises to 0.825 for a home team with an altitude difference of 3 695m and falls to 0.213 when the altitude difference is –3 695m," they report.
Research on altitude and performance
Since teams who do not live at higher altitudes have to acclimatise when they travel, does this mean that teams who live and train at higher altitudes have an advantage over those who don't?
According to the study, the advantage when playing at high altitude is not unusual given that "the differential in oxygen consumption between the two teams, and the effect this has on physiological response and football performance". However, they note that what was a surprising finding was that the high altitude teams also had an advantage when playing at low altitude and seemed to have a "significant advantage" over their low-altitude opponents at all locations.
This bodes well for our boys on the field.
They concluded that although the "living high and training high" theory is accepted as beneficial for athletes performing at high altitude, the effect this had on performance at sea level was less clear, and pointed to the fact this may be an effective training technique.
Train for a week or show up on the day?
Yet there are still those who stubbornly hold that teams who have trained at a low altitude can still arrive at the high altitude venue only hours before the game. On this, the experts still differ, although the research all seems to point towards the benefit of training at the high altitude at least a week before the game.
They suggest that "when possible, the best approach for avoiding altitude illness is to ascend slowly, allowing sufficient time for acclimatisation. And since FIFA has recommended minimum acclimatisation periods for certain altitudes, it appears that the general consensus is that altitude does affect performance and Tucker may be right – the smart teams will acclimatise before their matches.
Sources: Federation of International Football Associations; Dr Ross Tucker (sports scientist); British Medical Journal.
(Amy Henderson, Health24, updated August 2011)
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