Altitude in sports

Altitude in Sports : Decoding the Science Behind Records

A commonly used criterion to categorize sports is according to their venue. Therefore, they belong either to outdoor or indoor. The majority of them is characterized as outdoor, as they usually have less requirements regarding facilities. This implies though that athletes’ performance can be affected by a variety of exogenous factors.

Abstract

 In this research the author seeks to answer to which extent altitude affects performance in sports. The main goal is to find whether or not it works to athletes’ disadvantage, and if so, in which way. There has been a lot of discussion of this issue, especially the last decades where major international tournaments have been held in venues lying at high altitude. The text analyzes and compares data collected from various competitions. It is expected this research will inform athletes and fans about causes of different records in different elevations.

Introduction

During the latest version of Summer Olympic Games, 28 sports were featured in the programme. 18 included at least one event which took place in open – air facilities. Football, athletics, baseball, American football and some of the most popular sports worldwide are hosted in stadiums. Under these conditions, quite often athletes have to take into account many different parameters to set their strategy. Football matches taking place in high air temperature or sailing races in days with too little wind are two very common cases. Those factors affect not only the characteristics of an event, but also the physical performance of contestants.

Data Collection and Methodology

For the purposes of this study, the author will focus on three different team and individual sports. Those are football (not to be confused with American football), athletics and tennis. Two athletics events will be analyzed, long jump (anaerobic) and 5000m race (aerobic). For all three sports, data come from men competitions at international level. More specifically :

  • Regarding football, 20 games of World Cup 2010 and 20 games of World Cup 2014. Final result was either draw or win by one goal difference. None of the teams finished the game with less than eleven players.
  • Regarding athletics, 8 South American Championships between 1999 and 2015 were included for each event, plus Central American and Caribbean Games in 2002 and Pan American Games in 2011. For each event, the 8 best results in final will be inspected. In one case (5000m race in 1999) only 7 athletes participated and therefore an assumption was made that 8th record would be equal to that race’s average. 
  • Regarding tennis, data come from 8 games from 10 international tournaments (80 games in total) which took place in 2015. All tournaments were played at outdoor clay courts and were part of ATP Challenger or World Tour.

Performance will be evaluated according to altitude, using a different index for each sport. Total distance covered for football, athlete’s record for athletics and percentage of points won from aces for tennis. Altitude will be defined as low (0 – 599m), medium (600 – 1199m) and high (1200m and above) and will be obtained using Google Earth (version 9.20.60.2).

The Scientific Approach

High altitude effects on humans has been a topic with considerable debate over. As the altitude increases, different changes occur. Atmospheric pressure, defined as the force per unit area exerted against a surface (University of Illinois, 2010) by the weight of air above at surface, is 101325 Pa at sea level and oxygen concentration is 20.9%. Those numbers however fall linearly. At an altitude of 1500 meters for example, atmospheric pressure is equal to 64440 Pa. Oxygen concentration is constant, but air molecules are more dispersed. Therefore at same height as before one gets 40% less oxygen per breath than he does at sea level. More red blood cells need to be produced which can cause symptoms as nausea and headaches (Jackson, 2010). Thus being said, it takes a bigger effort at high altitude to breath (fatigue increases faster) but less to throw an object.

Focusing on Sports

Sports science could not be an exception to the previous rule. Even though outdoor sports are usually played at or close to sea level, there are a few occasions where circumstances make it impossible. Many inhabited mountainous areas can be found across the world, particularly in Central and South America, Central Asia and Central Europe. Playing conditions in those regions can be difficult but they rarely discourage practicing of sports. However, it is profound that they raise a lot of obstacles or restrictions. Athletes are exposed to extreme conditions which not only may affect basic elements of an event but also can push them to their limits. Despite not banning competitions from being held in high altitude (except from a few cases), federations set various rules and regulations.

FIFA had issued a temporary ban between May 2007 and May 2008 on international matches at more than 2500 meters above sea level. IAAF also sets a note about altitude on performances achieved in locations exceeding 1000 meters. There has always been quite a lot of discussion about effects of playing in high altitudes. As stated earlier, there are both advantages and disadvantages for an athlete. It is obvious that is more difficult to do aerobic exercise, but on the other hand less atmospheric pressure could result in better records when it comes to explosive activities.

On the following paragraphs of this research, the different effects of altitude on athletes’ performance will be deployed. In order to have a clear idea and big diversity of results, 4 events from 3 different sports (football, athletics and tennis) will be examined. Each one has a characteristic that is directly connected with physical performance and can be scientifically proved that is altered. 

Altitude Effects on Football

Football is a sport that requires a lot of activity. The average professional player runs approximately 10.5 km in a game. Thus being said, it is essential to be in great shape in order to be able to maintain performance throughout game. It would be interesting though to inspect what happens as matches take place in pitches many meters above sea level. In that case, do players run less because it is more difficult to breath or results are negligible?

World Cup 2010 is a tournament that raised a lot of interest. South Africa is a quite mountainous country. Games were played at an average altitude of 950m, while 6 out of 10 venues were lying at least 1200m above sea level. This had an influence at players’ performance, as many teams had to adjust to those playing conditions, despite FIFA officials denied that (Edwards, 2010). World Cup 2014 was mostly played at sea level but there were also some venues such as Curitiba (920m) and Brasilia (1172m).

Below, the difference in total team distance covered between low, medium and high altitude is displayed. As it is evident, the higher a game is played the lower the value of this performance index usually. To determine though if this difference can be considered significant, an A-NOVA test will be run. Confidence level in all A-NOVA tests of this research is set to 5%. 

The P – value returned is equal to 0.46 . Since it is greater than confidence level the null hypothesis cannot be rejected. In simple terms, there is not enough evidence to assume that all population means are unequal and therefore it would be wrong to say that total distance covered always decreases as altitude increases.

Altitude Effects on Athletics

Athletics is a series of events that can also be heavily affected by those conditions. The first big challenge was the 1968 Summer Olympics in Mexico, a city which lies at an altitude of 2240m. It was the first and last time till present that they have been held at such a high elevation. Furthermore, the majority of competitions in Europe take place at or very close to sea level. Something that is not the case in South America or East Africa and countries such as Colombia, Ecuador, Kenya and Ethiopia.

The first thought that someone would make is that long distance runners struggle when competing at high altitude. 5000M race is an event involving pure aerobic exercise. The data collected and the analysis implemented on it will shed a light on whether the extra effort they put is sufficient to overcome this obstacle.

As demonstrated below, average contestant record is worse by approximately 17 seconds at high elevations than low ones. This conclusion was probably expected. What is intriguing though comes from the results of the relevant A-NOVA test. The P – Value in that case is equal to 0.02, less than 0.05. Therefore, the null hypothesis can be rejected ; at least one population mean is different. Altitude affects athletes of 5000m race.

Apparently a slight difference in records in long jump is also noticeable. Lower air density is in fact an advantage for athletes of this event, since there is an increase in sprinting speed. Bob Beamon jumped at a distance of 8.96m in Mexico City. It is estimated that under the same conditions, but at sea level, his record would be 8.89m (Allain, 2012). However, in contrast with 5000m the P – Value is small (0.13) but not enough to reject the null hypothesis to claim that all results follow this rule.

Altitude Effects on Tennis

Tennis is a sport that requires excellent physical condition. Many games have duration greater than 2 or even 3 hours. Extreme weather conditions such as heat or rain can also affect players’ performance. Furthermore, altitude not only has an impact on human body but on another important aspect as well : tennis balls.

As mentioned earlier, lower air density means that items travel faster. When it comes to tennis balls, it allows the ball to bounce higher. ATP World Tour has featured tournaments played at high altitude such as Bogota and Quito. Even Madrid, Kitzbuhel and Gstaad which host major international tournaments lie more than 700m above sea level. It is obvious that it may be more difficult to return a serve in those courts. Good servers (such as Roger Federer) can take advantage of it and score more aces than usual.

The case of Ivo Karlovic is excellent to demonstrate the effects of altitude. The Croatian giant is one of the best servers ever and holds the record for the most aces in tennis history. Despite his age (born in 1979) which is considered to be quite advanced for a tennis player, he is still ranked at top – 100. This is mainly due to his performance at tournaments hosted at high altitude. In 2014 he made it to the final of Claro Open Colombia and earlier in 2018 to the round of 16 of Ecuador Open.

The impact of altitude could be measured by the percentage of points scored coming from aces, in order to find out if this index increases as elevation increases. The following graph illustrates the results of this analysis.

Unlike football and athletics where a correlation was found, even quite small in some cases to confirm any claim, in this case outcomes are vague. The index used does not even increase or decrease linearly. This is also underlined by the relevant P – Value which is equal to 0.96. However, there might be an explanation behind this remark. High altitude balls are a special category of tennis balls that are usually used for play at altitude greater than 1200m. They have less pressure than normal balls and greater diameter.

Results and discussion

In the current research, the impact of altitude on three different popular sports was analyzed. Data coming from international competitions taking place in various elevations was used. In most of the cases it was shown that it affects athletes, either positively or negatively. Nevertheless, only in 5000m race results had a statistical significance.

At this point it would be alluring to mention how altitude can often be turned from disadvantage into advantage. Using a method known as altitude training, athletes train themselves at high altitude for several days or even almost permanently. By doing so their body can adjust to lack of oxygen and improve attributes such as endurance and strength.

Conclusion

To wrap up, different effects of altitude were founded according to sport practicing. It is concluded that they can be scientifically explained to an extent, by using laws of physics. Quite often those results can be predicted and therefore the challenge for all stakeholders involved is to adjust their performance and playing conditions to those variations.


Bibliography

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I believe that sports and data science interrelate perfectly and their combination gives us the chance to understand better the whole science behind a single game. Therefore, for me Statathlon is a unique project that enables me to use my passion for research and writing about an important aspect of my life.

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