Can England overcome Mexico City’s altitude? It’s one of the biggest questions hanging over the last-16 tie against the co-hosts.
The Estadio Azteca sits around 2,240 metres (7,350ft) above sea level and Mexico have spent their lives playing and training in conditions England can only try to prepare for.
Thomas Tuchel has admitted there is no quick fix. England have trained for it, planned for it and talked about it throughout the tournament, but there is only so much you can do before arriving in one of the world’s highest cities.
So, I decided to find out what it actually feels like. Back home, I can usually run 5km in 22 minutes. Nothing spectacular, but a time I know I can consistently hit.
The question was simple: what would happen if I tried to run the same distance less than 24 hours after arriving in Mexico City? Would the altitude really make that much difference, or has the challenge been slightly overplayed?
I deliberately didn’t look at my watch during the run. I just wanted to see how my body reacted. And, it’s safe to say, it didn’t take long to find out.
Charlotte Daly decided to find out what it feels like in the altitude of Mexico City by comparing her UK 5km time to running the same distance in Mexico City
The Estadio Azteca sits around 2,240 metres (7,350ft) above sea level and Mexico have spent their lives playing and training in conditions England can only try to prepare for
Within the opening kilometre my chest felt unusually tight. I wasn’t gasping for air, but every breath felt as though it wasn’t delivering the same level of oxygen I was used to. My breathing was noticeably harder than it would have been back home.
At the same time, my legs felt incredibly heavy.
Part of that was probably the altitude, but part of it was undoubtedly the journey. I’d flown in from Atlanta less than 24 hours earlier and I could still feel the travel in my legs. They lacked their usual spring, making the opening two kilometres feel much tougher than a routine 5km would in England.
By around the third kilometre things began to improve. My breathing settled, my chest loosened and I found something approaching a rhythm. The run became more manageable, although it never quite felt easy.
The fourth kilometre brought something else. I was sweating far more than I normally would for that pace and could actually feel salt building up on my skin. Before long, the chafing started under my arms and between my legs.
That reminded me of a conversation I’d had with a family friend who served in one of the British military’s specialist units. He spent time doing altitude training in Mexico City and told me that Vaseline was considered essential.
The constant sweating and salt build-up caused serious chafing during long sessions, so everyone applied it under their arms and between their legs before heading out and kept electrolytes to hand.
It sounds like a small detail, but over the course of a 90-minute football match it is exactly the sort of marginal gain England’s support staff will have already considered.
The concern is that every sprint, every recovery run, every press and every change of direction asks just a little bit more of the body than it normally would
As for my experiment, I crossed the line in 24 minutes and 44 seconds. Back home, my typical 5km time is around 22 minutes, so I was almost three minutes slower. But, there are some caveats.
The opening kilometre almost certainly cost me time, while the heavy legs from travelling didn’t help either. Judging by how much more comfortable I felt later in the run, I’m fairly confident I could get much closer to my normal time if I ran again tomorrow. It wouldn’t suddenly feel easy, but it wouldn’t feel quite so unfamiliar either.
That could help explain the uproar over FIFA’s proposed change to the kick-off time. It’s common for elite athletes to use light exercise after travelling – whether that’s a spell on the bike, a walk or an active recovery run – to flush the journey out of their legs. A change to England’s schedule could have disrupted those plans, increasing the risk of players feeling heavy-legged before they had even kicked a ball.
One thing that did surprise me came after I’d stopped my run.
For about an hour afterwards, taking deep breaths still felt harder than normal. I wasn’t out of breath walking around, but trying to fill my lungs completely took noticeably more effort than it usually would.
So, what was my overriding takeaway from running in Mexico City’s altitude?
The science is well understood. The percentage of oxygen in the atmosphere remains the same, but the lower air pressure at altitude means each breath delivers fewer oxygen molecules to the body. The result is that your heart and lungs have to work harder to produce the same level of performance.
I felt that almost immediately.
That opening kilometre was noticeably harder than it would have been back home. My breathing was laboured, my chest felt tight and my legs felt unusually heavy. But equally, I settled into the run. I wasn’t doubled over at the finish, nor did I feel completely exhausted afterwards. It simply demanded more from me than the same run would have in England.
I crossed the line in 24 minutes and 44 seconds. Back home, my typical 5km time is around 22 minutes, so I was almost three minutes slower. But, there are some caveats
That, perhaps, is the important distinction.
The concern for England isn’t that players will suddenly be unable to run. They’re elite athletes. The concern is that every sprint, every recovery run, every press and every change of direction asks just a little bit more of the body than it normally would. Over 90 minutes, those small margins can add up.
England have understood that throughout their preparations.
Tuchel has admitted there is no quick fix, saying it is ‘impossible’ to fully adapt to the altitude in just a few days. Instead, the focus has been on reducing its impact as much as possible.
Players have trained wearing hypoxic breathing devices designed to replicate some of the respiratory demands of altitude, while workloads have been managed and the challenge factored into preparations long before arriving in Mexico.
The devices are not a magic solution. Sports scientists generally agree they cannot recreate every physiological adaptation that comes from living and training at altitude, but they can expose players to some of the breathing demands they are likely to experience.
In other words, England are not trying to eliminate the effects of the altitude. They are trying to make sure it hurts them as little as possible.
The Three Lions have already shown they can cope with uncomfortable conditions during this tournament. Group games in Dallas and Boston, followed by the Round of 32 clash in Atlanta, were played in extreme heat, forcing players to adapt their hydration, recovery and preparation.
The altitude may not decide the game on its own but if the match is level entering the closing stages it could be one of the margins that matters most
Altitude, though, is a different challenge. You can cool players down and manage the effects of heat. You cannot change the amount of oxygen available with every breath.
My run was hardly a scientific experiment and it cannot be compared directly with the demands of an international knockout match. England’s players are fitter, stronger and better prepared than almost anyone on the planet.
But it did offer a small insight into why so much emphasis has been placed on the conditions.
Nothing dramatic happened. I didn’t have to stop. I didn’t stagger over the finish line. Everything simply felt a little harder.
If I felt that during a 25-minute run, England will almost certainly feel it during a high-tempo, 90-minute knockout tie against a Mexico side that has spent years playing in these conditions.
The altitude may not decide the game on its own.
But if the match is level entering the closing stages, when tired legs become heavy legs and recovery between sprints becomes ever more difficult, it could be one of the margins that matters most. Especially given the fitness concerns throughout the England squad.
