WORLD CUP: England vs Mexico – my medical concerns about this game

I have never commented on football before on this blog (I am not even a big fan, yet I have been involved in doctoring for a team many years ago). Today, I make an exception because, in the very early hours of 6 July (UK time), England will be playing Mexico in the World Cup. This would, of course, not be worth writing about, were it not for a crucial detail: the match will be at the ‘Estadio Azteca’ in Mexico City, at about 2,240 meters above sea level, at a hight of roughly 2250 metres above seal level.

It is almost 40 years ago that I was interested in the human physiology at high altitudes. At the time, we concluded that this affects the fluidity of blood unfavourably, an effect that is likely to limit physical performance. But this is just one factor of several that can prove to be a significant handicap for a non-adapted athlete.

Playing at high altitude is medically significant mainly because the thinner air lowers the partial pressure of oxygen, so England’s players will absorb less oxygen with each breath. That means the muscles receive less oxygen when they need it most, e.g. during repeated sprints, accelerations, and recoveries.

The immediate consequence is a higher heart rate, heavier breathing, and faster, profounder and longer-lasting fatigue. In a football match, that can reduce high-intensity running, impair decision-making, and slow recovery between bursts of effort. The extraordinary fitness of professonal football players does not fully protect against low oxygen availability, because the body’s aerobic energy system is being forced to work under a constraint it is not used to. The body can adapt to high altitudes by making more red blood cells, but that process takes days to weeks, so a short turnaround leaves little time for meaningful acclimatisation.

Altitude also creates problems that are less obvious but might still turn out to be important. Sleep would be worse after arrival at high altitude, and poor sleep impairs recovery and performance the next day. In addition, there may also be a tactical issue that few have thought about. The ball travels a little faster and farther in thin air. This obviously can alter passing, shooting, and goalkeeping judgments.

The Mexican team is of course well adapted to the altitude. Their players are used to training and playing at Mexico City’s elevation, so the thinner air is far less of a shock for them. That matters because the home side can maintain intensity for longer, recover more quickly between sprints, and avoid unusual fatigue.

In short, high altitude is not just an inconvenience. It is a significant medical stressor that reduces oxygen delivery, worsens recovery, and makes sustained effort harder for the unadapted England team.

Fingers crossed, I hope they win nontheless.

Will I stay up to watch?

No, that would also be a significant medical stressor, one that I prefer to avoid.