Haile Gebrselassie says he will not run in the marathon at the 2008 Beijing Olympics because of the city's air pollution levels, reports Reuters.
Gebrselassie has set 26 world records during his career
The marathon world record holder suffers from asthma and missed the 2007 London Marathon because of the problem.
The Ethiopian will now run at the shorter distance of 10,000m in Beijing.
"The pollution in China is a threat to my health and it would be difficult for me to run 42km in my current condition," said Gebrselassie, 34.
"But I am not pulling out of the Olympic event in Beijing all together. I plan to participate in the 10,000 m event."
Last year Britain's Paula Radcliffe called in pollution experts to help her plans to run in the Games marathon.
At the time her husband and manager Gary Lough told BBC Sport that Radcliffe, who suffers from exercise-induced asthma, may have to change her medication in China.
"She may have to adapt her doses or medication but as long as we've done enough research and thought about it, it hopefully won't be an issue," he said.
"There's no point in us being especially concerned, because pollution's not really something you can control."