As a Brazilian and a citizen of the only nation to date with five stars on its jersey, I can say there is nothing quite like the atmosphere in our country when our national team takes the field. The moment the opening whistle blows, all differences seem to disappear. At least for ninety minutes, the dream of a sixth title, despite the team's limitations, soars as high as our "Angry Canary" mascot.
When Luck Meets Preparation
Naturally, the moment the ball starts rolling, millions of fans become experts. Within minutes, everyone knows exactly who should have been substituted and which tactical formation would have guaranteed victory. As South Park's iconic Captain Hindsight would say, once everything has played out, the solution always seems obvious.
Except for a few on-field geniuses like Lionel Messi, who can tip the scales of a match with an assist so extraordinary it borders on fiction, luck undeniably plays a direct role in the game. A miraculous save or a shot that deflects off the defensive wall can completely change the outcome.
Of course, this does not mean that lineups, tactics, and individual skill do not matter. They certainly do. Yet they also leave room for the sport's greatest appeal: unpredictability. This is not a new observation. A study published in the Journal of Sports Economics, analyzing data from seven European leagues, found that team skill explained about 40% of the variation in overperformance and underperformance over a season, while luck accounted for the remaining 60%. Overall, luck shifted league standings by nearly two positions.
Whether these figures will hold up remains uncertain. Other research groups still need to replicate the methodology, and future models should incorporate additional performance-related factors. Even so, the available evidence already suggests that teams can reduce some of that uncertainty through relatively simple, evidence-based strategies. Among them, few are as currently necessary, practical, and potentially impactful as proper hydration.
Hydration Is a Game Changer
Starting with this World Cup, FIFA introduced mandatory three-minute hydration breaks in each half. The measure did not come out of nowhere. FIFA first tested it during last summer's Club World Cup in the United States, when extreme heat left some players dizzy, making it clear that protecting athletes from heat stress required greater attention.
The breaks have critics, and they raise valid concerns.
Emma Hayes, head coach of the US Women's National Team, captured the issue well when she described them as "momentum breaks" — they benefit teams that have lost their rhythm while disrupting those in control of the match. "When you're on top, you don't want the break; when you're losing, you really do."
There is also a commercial aspect that is difficult to ignore. According to The Wall Street Journal, each break can be sold as advertising space for between $200,000 and $750,000. Across a tournament with 104 matches, that could generate between $42 million and $156 million in potential revenue.
The criticisms are legitimate. Yet the evidence suggests that these breaks make a meaningful difference for the players on the pitch.
Cooling the Body, Preserving the Sprint
A recent study compared two approaches:
● Conventional breaks (passive rest during a three-minute break, with room temperature water and a sports drink).
● Cooling breaks (the same protocol, but with chilled towels applied to the neck and shoulders and beverages cooled to 5°C or 41°F).
At moderate temperatures, around 25°C (77°F), the objective performance differences between the two groups were small. However, the players who received active cooling reported less fatigue, lower perceived exertion, and greater thermal comfort. In critical moments of a match, this subjective advantage may matter more than it seems.
The picture changes markedly as temperatures rise. At 33°C (91°F), players who took no breaks showed a significant decline in their ability to run at high speed throughout the match, a clear sign that their bodies were protecting themselves. Players who took only conventional hydration breaks experienced the same decline. However, those who received active cooling maintained their speed until the final whistle. In a game decided by sprints, that difference is far from trivial.
Another finding is equally striking. Even in matches played at 25°C, several players exceeded an internal body temperature of 39°C (102°F), the threshold at which heat-related complications begin to increase. Heat stress does not wait for extreme conditions. It can develop even when the weather feels relatively comfortable. [1]
The breaks represent an evidence-based strategy to protect athletes and preserve the quality of the game. Although they interrupt the flow of play, it is difficult to argue against a measure that helps players remain physically capable of competing for the full ninety minutes.
Heat, however, is only one part of the equation. Teams hoping to reach the final stages must also overcome other environmental challenges that can prove just as decisive.
Turning Evidence into Performance
To tackle these challenges, researchers from several countries recently published a guide in Sports Medicine summarizing the best available evidence on protecting athletes' health and performance during this World Cup.
The authors identify four major challenges:
Heat is perhaps the greatest concern. Soccer raises body temperature, and hot conditions amplify this effect, increasing the risk of heat exhaustion and heatstroke, a potentially fatal condition in which the body can no longer dissipate heat. Additionally, heat reduces the capacity for repeated sprints and impairs cognitive functions essential to the game, including attention, decision-making, and technical execution.
Altitude presents another major challenge. Nine matches will take place in Mexican cities at moderate elevations, where lower oxygen availability reduces aerobic capacity and slows recovery after intense exertion. Maximal oxygen uptake decreases with increasing elevation, helping explain why teams accustomed to high altitude often outperform opponents from sea level.
Air pollution and exposure to allergens also deserve attention. The sixteen host cities vary widely in air quality and pollen levels, which can reduce training capacity and compromise performance, particularly for athletes with respiratory allergies.
Finally, travel poses an unavoidable challenge in a World Cup spread across three countries and sixteen cities. Although no team will cross more than three time zones between matches, frequent travel can still cause jet lag, fatigue, sleep disturbances, and impaired recovery. Observational studies also suggest that eastward travel is linked to a higher likelihood of defeat, though many other factors influence match outcomes.
Fortunately, science not only identifies these challenges but also offers practical strategies to reduce their impact.
To manage heat, the primary recommendation is acclimatization. Initial adaptations typically appear around the fifth day, but evidence suggests that ten to fourteen days are needed to firmly establish those benefits. When that is not feasible, passive heat exposure through saunas, hot water immersion, or heated chambers can also produce meaningful, accelerated adaptations. Cooling strategies such as ice vests, cold towels, and chilled beverages, as discussed earlier, reduce heat stress before and during matches. Proper hydration with carbohydrates and electrolytes completes the picture.
To cope with altitude, the best-known approach is "live high, train low": athletes live at elevation to stimulate physiological adaptations while completing their most intense sessions at lower altitudes, where they can maintain training quality. Today, high-altitude hotels and hypoxic chambers [2] have made this approach far more accessible. The reverse strategy, "live low, train high," has athletes living near sea level while performing selected sessions in a low-oxygen environment. Some teams combine both strategies to maximize their adaptations.
To reduce the effects of air pollution and allergens, the main recommendation is to limit exposure wherever possible, especially for athletes with respiratory allergies. Arriving at the match venue several days before the competition allows for partial adaptation to local environmental conditions, while individualized treatment plans address the needs of more susceptible players.
For travel, the recommendations focus on protecting sleep and the body's internal clock through scheduled naps, gradual adjustments to sleep timing in the days before travel, and careful management of light exposure.
These recommendations show that preparation for the World Cup begins long before the opening whistle, reducing risks, protecting athletes' health, and increasing their chances of maintaining peak performance throughout the tournament.
Does this mean that following all these recommendations is enough to win the title?
Obviously not.
Preparing for the Unpredictable
As the authors of “FIFA World Cup 2026: Performance under Pressure: Scientific Guidelines for Success” note, uncertainty remains an inherent part of elite football, even in environments where every aspect of performance is closely monitored.
Perhaps this is what makes the World Cup so fascinating. Cape Verde entered the tournament as one of the least favored teams, yet it defied expectations by holding Spain and Uruguay to heroic draws and advancing to the knockout round.
Science can reduce many of the external variables that influence performance, narrowing the margin between fatigue and execution, between a mistimed step and a decisive sprint, between surviving the conditions and being undone by them. In 2026, winning before kickoff means recognizing that performance is shaped not only by tactics and talent, but by heat, oxygen, sleep, travel, recovery, and preparation.
The ball will still bounce strangely, heroes will still emerge from nowhere, and chance will still have its say. But the teams that best manage the science of the game may give themselves the one advantage every World Cup contender needs: being ready when luck finally arrives, turning ninety minutes of football into a spectacle that can captivate billions of people around the world.
[1] The 2026 World Cup has not published an official average stadium temperature, but available venue climate summaries suggest typical match temperatures ranging from about 64°F in Vancouver to the mid-80s in Dallas and Miami, with the tournament-wide average likely in the upper 70s Fahrenheit. The bigger issue is heat stress: nearly half the matches carry a meaningful risk of performance-impairing heat above 82.4°F.
[2] An environment that simulates altitude conditions by controlled reduction of oxygen levels.
