In June 2025, the FIFA Club World Cup offered a preview of the 2026 FIFA World Cup as matches were played across North America. This event highlighted the environmental conditions encountered by players, coaches, performance staff and fans across the United States (US).
Venues such a New Jersey and Los Angeles recorded game temperatures exceeding 28°C [1]. Official water breaks became necessary, even leading to some teams like Bayern Munich to keep their substitutes in the locker room during the first half of a game in Cincinnati to limit exposure to heat and humidity.
Though these conditions are regularly undertaken for teams of Major League Soccer (MLS), who compete in these demands every year in comparison to European domestic leagues.
MLS teams face substantial travel distance and demands due to the country’s vast geography, compared to European domestic leagues, resulting in frequent short (<3hr) and medium-haul (3-6hr) air travel for away games [2].
Due to geographical positioning of teams, away teams must navigate four time zones for competition: Eastern Standard Time (UTC -5:00), Central Standard Time (UTC -6:00), Mountain Standard Time (UTC -7:00), and Pacific Standard Time (UTC -8:00).
With teams situated across the US, players are not just exposed to chronological displacement and climate demands, but also altitude (>1400m).
Moreover, the cities selected to host the 2026 World Cup will expose national teams to these unique environmental conditions all in one tournament, such as the heat and humidity of Miami to the altitude of Mexico City, (see figure 1) requiring practitioners to account for these demands and periodise their training accordingly.
Figure 1. World Cup 2026 Stadium Venues and Associated Climate Demands.
Players Entering The World Cup
With the World Cup commencing in June, following the conclusion of many domestic leagues, players will be reporting to their national teams following playing over 46 games and 3700 minutes averaging 80 minutes per game (Declan Rice).
But in addition to this, individuals have also accumulated over 60,000 km of travel through international and European fixtures, equating to 1.5 times around the world, resulting in 36 hours of time-zone displacement (Luis Diaz) and significant circadian disturbance.
Heat, Altitude, and Travel Don’t Happen In Isolation
Scheduling of games has become a hot topic of debate in recent years, requiring practitioners to find the balance between optimising training schedules to ensure athletes are both well-conditioned and adequately recovered for the demands of performance.
With this being said, national teams will hold pre-training camps prior to the World Cup to create team cohesion but also physiological adaptation to upcoming climatic demands they are about to face come June.
Performance in heat (>21°C) has demonstrated to decrease physical activity across total distance and high-intensity actions such as high-speed running and sprint distance thus showing the impact of heat compared to ambient environments on running performance [3].
The location and length of training camps are crucial for ensuring players adapt physiologically within the necessary acclimation window.
Recent research has modelled the heat stress associated with tournament venues, revealing significant differences between afternoon and evening games.
In addition to heat stress, teams competing in Mexico City and Guadalajara will experience increased stress as a result of reduced oxygen levels associated with their elevated altitudes [4].
Figure 2 (below) illustrates the varying climate demands, demonstrated by Saudi Arabia’s environmental challenges during their group stage games: starting by competing in Miami at 6 pm (EST), then playing at Atlanta’s indoor venue, and finally completing the group stage at altitude in Guadalajara – three venues with distinctly different climates.
Given these environmental challenges, teams must adapt their preparation methods accordingly.
These findings, highlight the need for targeted interventions at the team level to delay or mitigate performance decline [5]. Hydration and cooling strategies such as scheduled fluid intake protocols or the use of palm cooling devices will aid lowering thermal strain.
However, periodised exposure to climate stressors combined with training under physiological strain is designed to lessen severe physiological demands [4].
For instance, England will hold a pre-training camp in Florida, scheduling friendlies kicking off at 4pm local time to stimulate high heat and humidity conditions.
This approach contrasts their group stages, which are expected to take place in more moderate weather, illustrating how teems can tailor their preparation to anticipated environmental demands.
Figure 2. Saudi Arabia’s Group Stage Environmental Challenges
The location of a team’s training camp during a tournament affects more than just climate adaptation.
Travel direction and time zones changes also play a significant role in influencing performance. Figure 2 shows a total round trip of more than 8,000km from base to origin and back, with an average distance of 2,866km per game.
Beyond travel distance alone, numerous studies have shown that eastward travel disrupts circadian rhythm. This disruption negatively impacts players routines, including nutritional loading windows and effective digestion [6].
With the US exposing teams to four time zones with a range from UTC -5 to UTC -8, presents similarities to the 2018 FIFA World Cup held in Russia, which required teams to navigate four time zones of UTC +2 to UTC +5.
Teams that travelled west to east during the tournament finished, on average four places lower and covered less total distance than teams travelling east to west or remaining within the same time zone. Highlighting circadian disruption with eastward travel within tournament football, compounding acute jet lag and fatigue [7].
What Practitioners Can Control
Drawing on experience managing many of the challenges outlined in this article within the Major League Soccer, practitioners are encouraged to focus on the variables they can directly control to achieve optimal performance on match day.
Central to this is the consistent monitoring of both internal and external load across training and competition.
Short term heat acclimatisation strategies, such as training camps in hot environments, are well supported, with evidence suggesting that as little as five days of exposure can reduce exercise heart rate [8].
As previously noted, players will typically arrive following the completion of their domestic season, and national teams will often have access to chronic external load data.
However, incorporating non-invasive fitness assessments such as a sub-maximal fitness test, provides practitioners valuable insights into the current internal load response, including positive reductions in exercising heart rate.
Figure 3 (below) illustrates the application of a sub-maximal assessment to demonstrate adaptive heart rate responses.
Internal load also encompasses players daily wellness measures and rating of perceived exertion, allowing additional insights into how players are adapting to and perceiving prescribed training demands.
However, tournament football presents a limited window of continued adaptation, once competition begins, with matches potentially occurring every four days. This, combined with environmental and travel stressors, possibly requiries more frequent and responsive monitoring.
When internal and external load data are interpreted alongside environmental and travel stressors, practitioners will be better equipped to contextualise performance adaptations and physical demands, rather than interpret workload in isolation.
Figure 3. Team Average, Sub-maximal Assessment of Internal Load Response to Training.
Before pursuing marginal gains or implementing novel technologies, it is important to ensure that foundational practices are robust and consistently applied.
Clear communication and collaboration between departments are essential.
For example, sports scientists can work closely with coaches to ensure session design aligns with principles of play, while advising on tailored training loads – adjusting intensity and volume during the competition phase, particularly in hot conditions.
This approach helps limit unnecessary physiological stress beyond what is planned, reducing the risk of fatigue carrying over into the subsequent sessions or matches.
In hot and humid climates, practical strategies such as weighing players pre and post training can support individualised rehydration strategies.
Alongside hydration, ensuring sufficient nutritional intake is essential to meet increased energy demands associated with heat exposure, high altitudes, and medium-haul air travel. Maintaining fuelling schedules and key intake windows become increasingly important during congested tournament schedules.
When teams are exposed to time zone displacement, interventions such as timed light exposure particularly following westward travel, can support circadian adjustment.
Similarly, adherence to standard sleep hygiene practices may promote longer sleep duration and quality when travelling eastward, supporting recovery and readiness across the tournament.
Conclusion
The 2026 FIFA World Cup is set to become one of the most environmentally demanding tournaments in modern men’s football, with teams facing a combination of heat, humidity, altitude and travel stress.
Practitioners who proactively plan for these demands, will be best positioned to support player performance.
Key Takeaways
- Kick‑off time may matter more than venue.
Afternoon fixtures will impose significantly greater heat stress than evening games, even at the same stadium.
- Environmental demands will accumulate.
Heat, humidity, altitude, travel, and schedule congestion are likely to overlap, increasing overall physiological and recovery load.
- Preparation must be targeted and proactive.
Training camps, acclimation strategies, and recovery plans should reflectanticipated match demands, not generic tournament preparation.
- Travel direction and time‑zone changes add performance risk.
Eastward travel and circadian disruption can compound environmental stress and should be factored into training and recovery decisions.
- Context is essential when interpreting performance data.
External load and running metrics must be evaluated alongside environmental and travel stressors to avoid misinterpreting performance changes.
References
- Ogden, M. Is the U.S. too hot to handle the 2026 FIFA Men’s World Cup? 2025 [cited 2025 04/11/2025]; Available from: https://www.espn.com/soccer/story/_/id/45703299/club-world-cup-heat-usa-mexico-fifa-2026-world-cup-concerns-temperatures-cooling-breaks.
- Draper, G., et al., Elite North American soccer performance in thermally challenging environments: An explorative approach to tracking outcomes. J Sports Sci, 2023. 41(11): p. 1107-1114.
- Pavlinovic, V., R. Morgans, and T. Modric, Temperature-Related Variations in Physical Performance During Elite Soccer Matches. Sports (Basel), 2024. 12(12).
- Lindner-Cendrowska, K., et al., Prospective heat stress risk assessment for professional soccer players in the context of the 2026 FIFA World Cup. Sci Rep, 2024. 14(1): p. 26976.
- Mullan, D., et al., Extreme heat risk and the potential implications for the scheduling of football matches at the 2026 FIFA World Cup. Int J Biometeorol, 2025. 69(4): p. 753-763.
- Reilly, T., How can travelling athletes deal with jet-lag? Kinesiology, 2009. 41(2.): p. 128-135.
- Zacharko, M., et al., Direction of travel of time zones crossed and results achieved by soccer players. The road from the 2018 FIFA World Cup to UEFA EURO 2020. Research in Sports Medicine, 2022. 30(2): p. 145-155.
- Buchheit, M., et al., Physiological and performance adaptations to an in‐season soccer camp in the heat: Associations with heart rate and heart rate variability. Scandinavian journal of medicine & science in sports, 2011. 21(6): p. e477-e485.
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