[1] Their mutual coach, Jong Myong-chol, describes their healthy rivalry in races and friendship as the key to their success.
[4][6] Kim's ability to maintain high speed and good composure in particular made her stand out.
[4] Kim subsequently won events such as 5,000 m, 10,000 m and 30 km in domestic tournaments like the 2009 Jonsung Cup and the 2011 national championships.
Sports journalist Pat Butcher considered the victory an important step toward the 2015 World Championships in Athletics, saying: "This is a huge win for North Korea.
[9][a] Kim started in the women's marathon at the 2015 World Championships in Athletics in Beijing, China, but did not finish the race.