Janeth Jepkosgei’s running career breakthrough year was 2006. On March 24 that year, she won the women’s 800m event at the 2006 Commonwealth Games with a time of one minute, 57.88 seconds. She beat veteran runner Maria Mutola of Mozambique. Later the same year, she won African Championships in Athletics in the 800m event. She also beat Kenyan 800m w0men’s record twice. Jepkosgei was awarded the 2006 Kenyan Sportswoman of the Year award.
Jepkosgei made history on August 28, 2007, when she won gold in the World Championship 800m final in Osaka, becoming the first Kenyan woman middle distance runner to achieve gold in 800m. She led from start to finish, winning in a time of 1 minute, 56.04 seconds, and beating the Kenyan record and world leading time (1:56:18) she had set at the heats two days earlier. She retained the Kenyan Sportswoman of the Year award.
On May 24, 2008, the 19-year old Pamela Jelimo set a new Kenyan record of 1:55.76, beating the one previously held by Jepkosgei. Jelimo’s dominance throughout the season prevented Jepkosgei from major victories, but won Olympic silver medal in 800m.
Janet’s father, Michael Busienei , was an 800m runner, as is her younger brother Dennis Kiprotich. Janet was born on December 13, 1983, at Kabirirsang, near Kapsabet, the home of 800m World champions Wilson Kipketer and Wilfred Bungei.
She started running at Kapsumbeiywo Primary School and took several events. Since 1998 she attended Sing’ore Girls’ High School near lten, famous for producing women athletes. She won national secondary school championship in heptathlon while in form one. Her specialty at the time was 400m hurdles.
In 2000 Jepkosgei won two gold medals at national secondary school championships in 400m hurdles and 800m. At the East Africa Youth Championships held in the same year she won 400m hurdles, and finished second in 800m.
She joined IOC—sponsored High Performance Training Centre in Eldoret in 2001. She was coached by 1988 Olympic gold medalist Pau Ereng’. The same year, she took 800m silver at the African Junior Championships, and the next year she took 800m gold medal at the World Junior Championships in Kingston, Jamaica.