Why is playing football at La Paz's altitude so hard?

Every time a national team visits Bolivia in qualifying, the same debate returns: is it fair to play more than 3,600 metres above sea level? Beyond the controversy, there's a clear scientific explanation of why altitude changes football.

Less oxygen in every breath

The air in La Paz has the same proportion of oxygen as at sea level, about 21%. What changes is the pressure: at around 3,600 metres atmospheric pressure is roughly a third lower. That means fewer oxygen molecules enter the lungs with each breath and less oxygen reaches the muscles.

For a footballer this has very concrete effects:

• Worse recovery between efforts. A sprint costs the same, but the body takes longer to be ready for the next one.
• Fatigue comes earlier. In the second half, players who aren't acclimatised usually run less.
• Dizziness, headaches or shortness of breath can appear, especially in the first hours after arriving.

The ball flies differently

With thinner air, the ball meets less resistance. It travels faster, goes further and curves less than expected. For visiting goalkeepers it's a problem: long-range shots take trajectories they aren't used to. For passers too: a long ball that lands perfectly at sea level goes too far at altitude.

That's why home teams tend to try more shots from distance, while visitors prefer to play short and calmly.

Adapting: arrive early or arrive just in time?

There are two classic strategies for teams visiting high altitude:

• Acclimatise for several days or weeks. The body starts producing more red blood cells, but the full process takes weeks, which is almost never possible in a professional schedule.
• Arrive a few hours before the match. The idea is to play before the strongest symptoms of altitude sickness appear. Many South American national teams choose this option.

Players who live and train at altitude have a natural physiological advantage, although when they play at sea level they feel the opposite effect in the heat and humidity.

The FIFA controversy

In 2007 FIFA tried to ban international matches in stadiums above a certain altitude. The decision affected cities such as La Paz, Quito and Cusco, and sparked a strong reaction from the Andean countries, which defended their right to play at home. The measure was suspended soon afterwards and matches at altitude continued.

Other high-altitude stadiums

• Estadio Hernando Siles, La Paz: about 3,600 metres. Home of the Bolivian national team, Bolívar and The Strongest.
• El Alto: above 4,000 metres. The Bolivian national team has also played recent qualifiers there.
• Quito: about 2,800 metres. Ecuador built a large part of its qualifications at home.
• Cusco: around 3,400 metres, home of Cienciano.

And in GolDraft?

GolDraft's simulator calculates expected goals from both teams' ratings and applies a home advantage in Legend Mode. We don't model altitude specifically, but it's one of the ideas people ask for most. In the meantime, you can play Bolivia against Argentina in the Live Match and see if your team lasts the 90 minutes.