Kristiansen started her career quite unremarkably, running 2:30 – 2:40 for her first few marathons. She won the bronze medal in the 3000 metres at the 1980 World Championships in Athletics and won the 1983 Houston Marathon in 2:33:27 while two months pregnant -- a fact she didn't know until two months later. It was not until she gave birth to her first son, Gaute, that her times began to improve. After winning the Houston Marathon again and the London Marathon in 1984, she placed fourth in the first Olympic women's marathon in Los Angeles. She also set two track world records in the 5,000 m on 28 June 1984 and the 10,000 m on 27 July 1985, at the Bislett Games in Oslo. In 1985 she won the London Marathon again in a new world record of 2:21:06, the previous record was 2:22:43, set in the 1983 Boston Marathon by Joan Benoit. Later in 1985 she lost to Benoit in the Chicago Marathon, running 2:23:05 for second place. 1986 was Kristiansen's best year in track. After she won the Boston Marathon in hot conditions, she set a new world record in the 10,000 m, smashing her own world record from 1984 by 46 seconds. Then she broke the 5,000 m world record, running 14:37.89. On 5 April 1987, she won a half marathon in Sandnes, running 1:06:40, but the course was not measured properly and the world record still remained with Joan Benoit. She won the Chicago Marathon, once again in hot and humid conditions, running 2:27:08. She ended the year winning the 10,000 m event at European Championships, running the 2nd fastest time ever and nearly 40 seconds ahead of the second-place finisher. In 1987 Kristiansen attempted to break her marathon world record in London, but she slowed in the second half and won in 2:22:48. She won the first World Championships Women's 10,000 m in Rome, despite a leg injury. In 1988 she won the London Marathon for the fourth time, finishing in a time of 2:25:41. Despite a 1:09 first half, she slowed dramatically in the second half, however she was still five minutes ahead of any other woman. At the Olympic Games in Seoul, she participated in the 10,000 m, and even though she was the heavy favourite, she dropped out after seven laps with a fractured bone in her foot. She returned to racing in 1989, winning the Boston Marathon in 2:24:33 despite the heat in the latter stages. She decided not to run any track races that year, but she still won a few road races in Europe. Her final marathon was the 1989 New York City Marathon, which she won in a time of 2:25:30, running away with it from the start. Gradually she raced less and less, despite winning the 1990 City-Pier-City Loop in The Hague. She retired in 1993 and lives with her husband and two children in Oslo, Norway. She won 14 out of 26 marathons.
Achievements
Note: The 1987 World Road Race Championship was held in November while the 1988 edition was held in March.
World Records
Broke 5000 m world record with 14:58.89 in Oslo, 28 June 1984 – first woman to run under 15 minutes.
Broke 5000 m world record with 14:37.33 in Stockholm, 5 August 1986
Broke 10,000 m world record with 30:59.42 in Oslo, 27 July 1985 – first woman to run under 31 minutes.
Broke 10,000 m world record with 30:13.74 in Oslo, 5 July 1986
