England’s altitude – A runner who landed in Mexico City hours before a 5k found her chest tightening, her legs turning heavy, and even deep breathing staying harder afterward—an experience that mirrors the worry facing England ahead of their last-16 tie at Estadio Azteca.
England’s last-16 test in Mexico City isn’t just about tactics and opponents. It begins, disturbingly, with the first breath.
The Estadio Azteca sits around 2. 240 metres above sea level. and Mexico have lived and trained in the thin-air conditions for years. England can prepare for altitude—train for it. plan for it. talk about it constantly through the tournament—but there is only so much you can do before you arrive and feel it in your own body.
To understand what that actually means, Charlotte Daly decided to run a 5k in Mexico City just hours after arriving. Her starting point back home was clear: she can usually run 5 kilometres in 22 minutes in the UK. a time she knows she can hit consistently. In Mexico City. she deliberately did not look at her watch during the run so she could focus on how her body responded.
Within the opening kilometre, her chest felt unusually tight. She wasn’t gasping. but every breath seemed less effective—like it wasn’t delivering the same level of oxygen she was used to. Breathing became noticeably harder than it normally would have been back home. At the same time, her legs felt incredibly heavy.
She didn’t just blame the altitude. She had flown in from Atlanta less than 24 hours earlier and could still feel the journey in her legs. The “spring” she relies on wasn’t there, making the first two kilometres tougher than a routine 5k in England.
Around the third kilometre, things began to improve. Her breathing settled, her chest loosened, and she found something approaching a rhythm. The run became more manageable, though it never quite felt easy.
The fourth kilometre brought a different problem: she was sweating far more than normal for that pace and could feel salt building up on her skin. Chafing quickly followed—under her arms and between her legs.
That detail took her straight to a conversation she’d had earlier with a family friend who served in one of the British military’s specialist units. The friend had spent time doing altitude training in Mexico City and told her Vaseline was considered essential. The reasoning was practical: constant sweating and salt build-up can cause serious chafing during long sessions. so everyone applied it under their arms and between their legs before going out. while keeping electrolytes to hand.
Daly frames it as a marginal gain issue—exactly the kind of small edge a football staff might obsess over when you’re playing in unfamiliar conditions.
When she crossed the line, she finished in 24 minutes and 44 seconds. Back home, her typical time is around 22 minutes, meaning she was almost three minutes slower. But she pointed to caveats: the opening kilometre almost certainly cost her time. and the heavy legs from travelling didn’t help either. By how much more comfortable she felt later in the run. she believed she could get much closer to her usual pace if she ran again tomorrow. It wouldn’t suddenly feel easy, but it wouldn’t feel quite as unfamiliar.
Her experiment also connected to a wider tournament worry: 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 changed schedule for England could disrupt those plans, leaving players heavy-legged before the first kick of the match.
There was another lingering effect after she stopped. For about an hour afterwards, taking deep breaths still felt harder than normal. She wasn’t out of breath walking around, but filling her lungs completely took noticeably more effort than it would have at sea level.
What she took from the science is straightforward: the percentage of oxygen in the atmosphere stays the same. but the lower air pressure at altitude means each breath delivers fewer oxygen molecules. The result is that the heart and lungs have to work harder to produce the same level of performance—and she felt it almost immediately.
That opening kilometre was harder than it would have been back home: breathing laboured, chest tight, legs heavy. Yet she also settled into the run, finishing without having to stop and without staggering at the end. Nothing dramatic happened. The experience, in her words, wasn’t about collapsing. It was about being made to work harder than the same effort would demand in England.
That’s where the England concern sharpens. It isn’t that altitude will make elite players unable to run. The worry is that every sprint, every recovery run, every press, and every change of direction asks the body for just a little more. Over 90 minutes, those “small margins” can add up.
Thomas Tuchel has already acknowledged there is no quick fix. He admitted it is “impossible” to fully adapt to the altitude in just a few days, so the focus has been on reducing its impact as much as possible rather than pretending the conditions won’t bite.
England’s preparation has included training while wearing hypoxic breathing devices designed to replicate some of the respiratory demands of altitude. along with managed workloads and the challenge factored into planning long before arriving in Mexico. The devices, though, 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.
The point is that England are not trying to eliminate the altitude. They’re trying to make it hurt less.
They have already shown they can cope with uncomfortable conditions during the tournament. Group games in Dallas and Boston were played in extreme heat, followed by the Round of 32 clash in Atlanta. Those matches forced players to adapt hydration, recovery, and preparation. But altitude is different: you can cool players and manage heat effects. You cannot change the amount of oxygen available with each breath.
In Daly’s telling, that’s why the margin matters most late in the game. Altitude might not decide the tie by itself. 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 factors that swings the outcome.
Especially because England have had fitness concerns throughout their squad.
MISRYOUM Sports News England Mexico City Estadio Azteca altitude FIFA kick-off time Thomas Tuchel hypoxic breathing devices 5k run Charlotte Daly fitness concerns
So like… just run slower? lol.
I mean England should’ve known Mexico City is high up. Why are we acting surprised like it’s the first time anyone’s ever flown there? Also how do you even “train” for your chest tightening, that sounds terrifying.
Wait I’m confused—if England already “trained for it” then why is the runner still feeling heavy legs after hours? Maybe it’s not altitude but like pollution or something. They talk about breathing like it’s a whole disease.
Altitude fear is real but this article feels kinda dramatic. Like, they’re playing soccer not climbing Everest. If Mexico City trained there for years then England should’ve gotten the same fitness package before they landed, right? I heard once it’s just dehydration and bad sleep, so maybe that’s it more than “thin air.”