Heat may become the biggest challenge at the World Cup
Long-distance travel, high temperatures and matches at altitude can all affect player performance during a World Cup. Football researcher at the 海角社区 Chris Carling points to heat as the biggest challenge.
When a World Cup begins, attention is usually focused on star players, tactics and spectacular goals. But behind the scenes, another battle is taking place – one that may influence which teams perform at their best.
Even the world's top footballers depend on their bodies functioning optimally.
According to Chris Carling, who researches elite football at the 海角社区, a range of factors away from the pitch can affect performance during a major tournament.
Previously, he served as Head of Performance and Research at the French Football Federation and has worked throughout his career in some of Europe's leading football environments.
“There are so many contextual factors that influence a player's ability to perform at the highest level,” he says.
Heat could leave its mark
If Chris Carling has to identify one factor that could have a particularly strong impact at the 2026 FIFA World Cup, the answer is heat.
Several host cities are expected to experience temperatures above 30°C during the tournament, and many players rarely train or compete in such conditions.
“Heat is arguably the main concern,” he says.
Chris Carling's own research has shown that matches played in temperatures above 31°C can significantly reduce repeated sprint performance and jumping performance compared with normal conditions. High-intensity running also tends to decline towards the end of matches as a result of hyperthermia and dehydration.
As a result, teams that prepare thoroughly through heat acclimatisation, cooling strategies and carefully planned hydration protocols may gain an advantage over their opponents.
Limited time for recovery
For many players, the challenge begins long before the opening match.
Some arrive directly from Europe's top leagues, while others finish their club seasons with domestic cup finals or UEFA Champions League matches.
“For some players, there will be only a very short break between their final club match and the World Cup. That leaves very little time for recovery,” says Chris Carling.
Preparing for a World Cup is therefore not only about training, but also about recovering from a long season filled with matches and travel.
The issue is not merely theoretical.
Research from the 2002 FIFA World Cup showed that players who subsequently underperformed had played significantly more matches in the ten weeks leading up to the tournament than those who performed as expected.
Almost two thirds of players who had played more than one match per week during that period either suffered injuries or underperformed during the World Cup.
Today, the global players' union FIFPRO recommends a minimum four-week off-season break with no training, travel or media commitments. However, that recommendation is difficult to reconcile with a World Cup played immediately after a long club season.
The body must adapt to new conditions
Travelling to the tournament can be a challenge in itself.
Some national teams will cross several time zones, disrupting circadian rhythms and increasing fatigue.
Upon arrival, players may encounter climatic conditions that differ greatly from those they are accustomed to.
“They may be exposed to temperatures above 30 degrees Celsius, moderate altitude, air pollution and allergens. All of these factors can influence performance,” says Chris Carling.
Playing at altitude
One location that Chris Carling will be watching closely is Mexico City.
The city's Estadio Azteca sits around 2,200 metres above sea level, making it higher than any of the venues used during the 2010 FIFA World Cup in South Africa.
Research has shown that teams playing above 1,200 metres during that tournament covered approximately three per cent less distance than teams competing at sea level.
Consequently, teams that prepare specifically through altitude training and acclimatisation strategies may gain an advantage in matches played high above sea level.
Searching for small advantages
National teams work hard to prepare for the conditions they expect to encounter during the tournament.
Some undertake heat-acclimatisation programmes several weeks before the competition.
Others rely on cooling vests, ice towels and carefully designed hydration strategies.
“There are a range of strategies that can help players perform optimally under challenging conditions,” says Chris Carling.
Efficiency decides matches
Ultimately, success still comes down to delivering when matches are decided.
“The best teams and the best players are those who are most efficient at creating good scoring chances and putting the ball in the net,” he says.
When the differences between teams are small, even modest physiological advantages can make a difference. As a result, factors away from the pitch may help determine which teams are best equipped to succeed throughout a long and demanding tournament.
Five factors that can influence player performance at the World Cup
- Temperatures above 31°C can reduce players' ability to sprint and perform high-intensity actions.
- Limited recovery time between the club season and the World Cup may increase the risk of injury and underperformance.
- Jet lag can affect sleep, concentration and recovery for several days.
- Matches played at altitude can make it harder to maintain normal playing intensity.
- Teams use heat acclimatisation, altitude training, cooling strategies and hydration plans to prepare for challenging conditions.
Meet the researcher
Chris Carling is a researcher at the Research Unit of Sport and Health Sciences, Department of Sports Science and Clinical Biomechanics, 海角社区, and former Head of Performance and Research at the French Football Federation.