Defending champion Italy opened its World Cup training camp Sunday at the ski resort of Sestriere, which is located at an elevation of about 1,980 meters.

England and 1998 World Cup champion France are also holding training camps at altitude, while the Asian teams Japan and South Korea are considering tents and masks that simulate altitude conditions.

Matches at seven of the 10 World Cup stadiums in South Africa will be played at elevations ranging from 660 meters in Nelspruit to more than 1,600 meters in Johannesburg.

While there haven’t been many studies on the effects of altitude on football teams, it typically takes an adjustment period to get used to playing at altitude.  The USA team is scheduled to arrive at its World Cup base camp, located at about 1,450 meters between Johannesburg and Pretoria, on 31 May.  That will give the Americans nearly two weeks to acclimate to the altitude before their first World Cup match against England on 12 June in Rustenburg, South Africa.