By MARK McDONALD
Her death was confirmed by her husband, Jack.
Ms. Waitz was just 18 when she competed in the women’s 1,500-meter race at the 1972 Munich Olympic Games. She was eliminated in the first round in Munich but her career as a competitive runner and pioneering athlete was just getting started.
Ms. Waitz set the world record at 3,000 meters in the summer of 1975, but did not make the finals of the 1,500 at the 1976 Olympics in Montreal. Her chance at a third straight Olympics was foiled when Norway joined the American-led boycott of the 1980 Moscow Games over the Soviet invasion of Afghanistan.
Fred Lebow, the director of the New York City marathon, invited Ms. Waitz to compete in the 1978 New York race. It would be her first-ever marathon, and it was understood that she would run as a rabbit, or early pacesetter, for the established and favored women marathoners.
She also planned to use the trip to New York to celebrate her retirement from competitive running, renew her focus on her job as a teacher, and perhaps start a family with Mr. Waitz, whom she had married in 1975.
“But, instead, I quit my job teaching and never had kids,” she said in a 2008 interview with the New York Road Runners club.
Ms. Waitz not only won the 1978 New York race, but also set a world best, finishing in 2 hours 32 minutes 30 seconds — 2 minutes faster than the previous mark.
Over the years she would win the New York event eight more times.