When Olympic triathlon champion Gwen Jorgensen lines up for her first 26.2-mile race at the New York City Marathon on Nov. 6, it will be hard to judge her performance.
Perhaps the best measure will be her time versus those of previous Olympic triathlon medalists in their marathon debuts.
Jorgensen is recognized as the greatest female runner among top-level female triathletes, perhaps of all time, with an ability to make up deficits of more than one minute on the 10km run after swimming 1,500 meters and biking 40 kilometers.
Swiss Nicola Spirig, the 2012 Olympic triathlon gold medalist, made her marathon debut in 2014 in 2:42:53. Sprig, though, had more long-distance racing experience than Jorgensen, including a half marathon.
Jorgensen, 30 and a former University of Wisconsin distance runner and swimmer, has never tackled more than 10 miles in training, according to The New York Times.
“When you ask athletes what they want to do after they win gold or the Super Bowl, they say they want to go to the happiest place on earth,” Jorgensen said, according to the newspaper. “Running is my happiest place. It’s my Disneyland.”
Portugal’s Vanessa Fernandes shared triathlon’s longest top-level international winning streak before Jorgensen strung together 13 wins in a row.
Fernandes, the 2008 Olympic triathlon silver medalist, clocked 2:31:25 in her first marathon, but it came in 2015, four years after her last elite international triathlon.
The 2015 New York City Marathon women’s winning time was 2:24:25 by Kenyan Mary Keitany. The top American, Laura Thweatt, ran 2:28:23.
This year’s American field may be stronger, with Olympic track distance runners Molly Huddle and Kim Conley making their marathon debuts.
Other Olympic triathlon medalists, including 2004 gold medalist Kate Allen and 2000 silver medalist Michellie Jones, have moved up to the Ironman — a 2.4-mile swim, 112-mile bike and a marathon.
In 2014, Jorgensen said she didn’t see herself ever doing an Ironman.
MORE: What Jorgensen asked Ironman star Mirinda Carfrae