Early running Born in
Kamasia,
Marakwet District, Mosop started running while at primary school and later went to
Marakwet High School. He qualified for the
2002 IAAF World Cross Country Championships held in
Belfast, where he finished tenth in the junior race. It was in this occasion that he joined the management of the Italian Gianni Demadonna, and started to be coached by Renato Canova, that developed his talent from the youth category up to the current international level. At the
2002 IAAF World Cross Country Championships in
Lausanne he fared slightly better, finishing 7th in the junior race. At the
2003 All-Africa Games, he was fifth in men's 10,000 metres. He made his Olympic debut at the
2004 Athens Olympics and was seventh overall in the
10,000 metres final. Mosop also won the
Giro Podistico di Pettinengo 9.6 km race in 2004. He was the winner of the
Almond Blossom Cross Country in March 2005 and placed 18th at the
2005 IAAF World Cross Country Championships soon after. Competing in the 10,000 metres in the
2005 World Championships, he won the
bronze medal, setting a personal best of 27:08.96 minutes. He occasionally runs the 3000 and 5000 metres and holds personal bests of 7:36 min and 12:54 min in those events. He headed further up the podium at the
2007 IAAF World Cross Country Championships. He finished second in the senior race and took the team gold with Kenya. He took back-to-back wins at the
Giro al Sas 10K race in 2007 and 2008. In March 2009 he won the
Cross di Alà dei Sardi in Sardinia. He returned to world competition two years later, but he could not repeat his medal form at the
2009 World Cross Country Championships (finishing in eleventh place), although he still won team gold with Kenya. Mosop won the men's race at the 2010
Stramilano Half Marathon, clocking 59:20 for the win over
Silas Kipruto. His coach stated that Mosop was progressing as a road runner and might make a move to the
marathon distance. Attempting to defend his title at the
Giro Media Blenio 10K (which he won in 2009), he finished second in a sprint finish just behind
Imane Merga. He was chosen for the Kenyan team at the
2010 IAAF World Half Marathon Championships and he finished in tenth place. At the
Zevenheuvelenloop 15K race, he was off the pace and finished sixth – almost two minutes behind
Leonard Patrick Komon who set a world record.
2011: Marathon debut and world records His first race of 2011 was the
Paris Half Marathon, where he finished second behind
Stephen Kibet. On 2011-04-18, he ran his marathon debut at the
Boston Marathon, coming second in a time of 2:03:06. He and fellow countryman
Geoffrey Mutai ran what at the time were the fastest times ever recorded for a marathon, shattering the time of the then existing world record (2:03:59 by
Haile Gebrselassie) by nearly one minute, and the Boston course record by nearly three minutes. Helped by ideal cool temperatures and a strong tailwind on the point-to-point course, the lead pack reached the halfway mark on record pace of 1:01:54. The two Kenyans broke away from the pack at 30 kilometres and ran stride-for-stride over the last 12 kilometres until a sprint in the final straight-away by Mutai gave him the victory by four seconds, 2:03:02 to 2:03:06. Because Boston is a point-to-point course, with an overall downhill slope, the times were not officially recognised. The IAAF rules essentially require marathon records to be established on a loop course (thereby neutralising the impact of wind and course elevation changes). The previous record at Boston was 2:05:52, set in 2010 by
Robert Kiprono Cheruiyot who was the first to break 2:06 at Boston, while the current world record (yet to be ratified) is 2:02:57, run by
Dennis Kimetto at Berlin in 2014. As part of the 2011
Prefontaine Classic, Mosop was selected in an attempt to break the
world record for the infrequently contested 30,000 m on the track. He shattered
Toshihiko Seko's thirty-year-old world record by over two and a half minutes, running a time of 1:26:47.4 hours. He also smashed Seko's 25,000 m record by a minute and a half, passing the 25K intermediate mark at 1:12:25.4 hours. He stepped down in distance to run at the
B.A.A. 10K in June and took third place on the podium. 2011-10-09, Mosop won the
Chicago Marathon with a time of 2:05:37, beating
Sammy Wanjiru's course record by four seconds. At the start of 2012, he was sixth at the
Paris Half Marathon in preparation for the
Rotterdam Marathon the following month. He was the pre-race favourite and attempted to break the marathon world record, but fell behind
Yemane Tsegay and
Getu Feleke, eventually finishing with a time of 2:05:03 hours. Nevertheless, he was selected for the Kenyan Olympic marathon team, but a tendon injury forced him to withdraw and he was replaced by
Emmanuel Mutai. ==Personal life==