The world record holder has a knee injury.
Two of the top Kenyans square off Sept. 29 in the German capital.
There is a performance threshold in running, but it's not the lactate threshold.
Despite how close runners are to the magic mark, it doesn't seem possible right now.
The 29-year-old has not run a full marathon since the Olympic Trials last year.
It's filled with world champions and record holders.
The 26.2-mile race has become more competitive for both the men's and women's divisions.
He DNF'd there in 2012.
He thinks he has a shot for 2:05 in Fukuoka this weekend.