MADRID, Aug. 1 (Xinhua) -- Spanish Marathon medal hopeful Chema Martinez said on Friday that he was worried about the heat in Beijing.

    Before setting off from Spain on Wednesday, Martinez insisted that heat and humidity would be a problem for him in the Olympic Games.

    Martinez was part of the first Spanish expedition to fly to Beijing and after a flight of over 10 hours, he admitted that jet lag was also a factor.

    "At the moment I am tired, but I think we have made the right decision to travel so early," he told the Diario AS newspaper.

    "The conditions are going to be a big factor. That is why I have got here a month beforehand. So I don't suffer like I did in (2007 World Championships) Osaka."

    He said Asian runners might have advantage in these conditions.

    "I think there could be a surprise with an Asian runner, who may not be among the favorites, like the Japanese, who I suppose are more used to the conditions and who will have an advantage."

    "Of course the Kenyans are always on a higher level. I will have to fight hard to keep on their heels," he said.

Special report: 2008 Olympic Games