Veteran Germany striker Miroslav Klose says it is crucial to have a fit team heading to the World Cup and admits the South American sides have an advantage due to the climate.
Klose heads into his fourth World Cup finals not content just with having become the all-time record national goalscorer but determined to leave Brazil as the record marksman in World Cup history.
But he knows the conditions will be against Germany and the rest of Europe's elite with no European country ever triumphing on South American turf.
"Realistically, there are five or six teams playing for the title," said Klose, the only recognised striker in coach Joachim Low's squad.
"The south American teams have an advantage, in my opinion, as they know the climate better.
"I have spoken to my Lazio colleagues who played for Italy last year at the Confed Cup and they said they were struggling for air after 20 minutes.
"You need a fit team to go to Brazil and push themselves to the limits."
Poland-born Klose became Germany's all-time top-scorer on Friday when he netted his 69th goal in his 132nd appearance in their 6-1 friendly thrashing of Armenia.
He bettered the previous record set by Gerd Muller, who scored the winner in the 1974 World Cup final to claim his 68th goal in 62 appearances for West Germany.
Klose could return from Brazil as the all-time top scorer at World Cup finals as his 14 goals leaves him one short of retired Brazilian star Ronaldo's record of 15.
Klose was the top-scorer at the 2006 World Cup in Germany with five goals, having finished second with another five at the 2002 tournament, while he scored four in South Africa four years ago.
"I hope to have the chance to score one or two goals, and anyone who knows me is aware that the World Cup scoring record is a target of mine," said Klose.
Klose signed a contract extension in May with his Italian side Lazio until June 2015, with an extra year's option, but expects next season to be his last.
"At the moment, I assume that 2015 will be the end, but it depends on my fitness and any injuries," he told German daily Bild.
Klose jets to Brazil with question marks over his fitness after an injury-ravaged season restricted him to seven goals in 22 appearances for Lazio.
"When he's fit, then he is terribly important for my team," said Low, a self-confessed Klose fan. "His secret is his professionalism, his strength is his will."
Klose said Germany's impressive display against Armenia, with five goals in 17 second-half minutes, was more important to him than breaking Muller's record.
"Of course, the goal record means a lot to me, but it was more important for us to be in form," said Klose.
"When we play as well as we did in the second-half, then we create plenty of chances and I'll score goals. I want to play and I know I can help the team."