Career
She has a personal best of 2:20:48 hours for the distance. Hailing from the Nandi District in Kenya, Sumgong began to compete abroad in 2004. In one of her first elite races, she came second at the Gothenburg Half Marathon.
She started to establish herself as a runner on the American road circuit in 2005.
She ran a 15K personal best of 49:39 minutes at the Utica Boilermaker in July and, that November, she ran the fastest ever half marathon in Trinidad and Tobago, winning a race in Saint Augustine in 1:12:08 hours. She came third at the Azalea Trail Run the following year.
She made her European debut at the 2007 Frankfurt Marathon and she came fourth in an improved time of 2:29:41 hours. Her next outing over the distance came at the San Diego Marathon and she was runner-up in 2:30:18 hours behind Yulia Gromova.
She signed up to work for the Kenyan Armed Forces in 2009.
Having missed the 2009 season, she returned in 2010 and was runner-up at the San Blas Half Marathon, fifth at the Berlin Half Marathon and fifth at the San Diego Marathon. Sumgong was seventh at the highly competitive Kenyan Cross Country Championships at the start of At the Boston Marathon, high profile withdrawals and hot running conditions worked in her favour as the race came down to a sprint finish against Sharon Cherop, with Sumgong taking the runner-up spot two seconds behind. Sumgong tested positive for the banned substance prednisolone in her post-race anti-doping test and was given a two-year ban from competition by Athletics Kenya.
However, she was cleared on appeal by the IAAF in September, as the local injection which Sumgong had received was permitted under the governing body"s rules.
Cleared to race, Sumgong again finished behind Cherop at that year"s Philadelphia Half Marathon, taking third place. Later in the year, she finished second at the New York City Marathon, losing a close battle with compatriot Mary Keitany, whose winning margin of three seconds equalled the narrowest in race history.