A few months ago the man who owned the track for almost a decade and in recent years has evolved into a dominant marathoner (and current world record holder), annouced that he will not be competing in the Bejing Olympic marathon.

At 35 years old, "Geb", has exercised-induced asthma.  He fears the conditions in China could damage his body and prevent him from competing in a elite level down the road in future competitions.  Over 42k the pollution could damage his lungs.

He plans to compete in the 10,000 meters, an event which he was 2 gold medals.  Just this past fall Geb ran a 2:04:26, the world record, yet he does not have a gold medal in that event.

A few weeks ago Geb ran a 26:51 for 2nd place and it looks like he will be in Olympics for the 10,000.  I will never be one to doubt  this man's running ability but as fast as he is in the 10k there are a hand full of guys that should beat him, like Kenenisa Bekele, Sileshi Sihini, etc.. (and he probably knows this).  Also, he will be passing up on another world record marathon chance in the fall if he runs the marathon.

My question is why the 10,000 over the marathon?  Yes, I know he said it's the pollution but if Geb is worried about the marathon and breathing then wouldn't the 10k be worse?  The rate of breathing is the problem and at the very high VO2 max intensity (95% of max) of the 10k will be worse.  The marathon will have higher total volume of breathing but 2 hours still is not long enough.  Think of it this way, if you are sick and coughing up green crap what is worse an easy long jog are a short hard burst, even just a mile fast? 

Geb has enough physiologists to know this, so what is his reason?