She was the 2006 World Junior and 2007 World Youth champion in the steeplechase, the former of which was done at age 16 running barefoot.

In 2006, Chepkurui burst onto the scene winning the 2006 World U20 Championships title in the 3000 metres steeplechase in a championship record time of 9:40.95.

The win was all the more impressive by the fact that she was only 16 years old and running barefoot, competing against a field of mostly 18 and 19 year old athletes all wearing running spikes.

[4][2] In 2007, Chepkurui won her second global gold medal at the 2007 World Youth Championships, this time competing against younger (U18) competitors over a shorter distance (the inaugural 2000 metres steeplechase).

[5] In 2019, Chepkurui became a pacemaker for the Diamond League, including rabbiting for the 2019 Prefontaine Classic women's steeplechase.