England are facing Mexico at the Azteca Stadium in their next World Cup match at 1am BST on Monday.
The Azteca stadium which sits more than 7,300ft above sea level. At that height, oxygen intake can fall by more than 7% until the body has time to acclimatise.
That can reduce stamina and make it harder for players to sprint or press for long periods.
But, England have a secret weapon to try to overcome the altitude, as ITV News Science Correspondent Martin Stew explains.
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