As the oldest annually contested marathon in the world, the Boston Marathon often sets standards in the world of running. So when the Boston Athletic Association, the race’s organizer, announced this week that it would invite nonbinary athletes to compete next year without having to register in the men’s or women’s divisions, it sent a signal to runners like Cal Calamia.

“The Boston Marathon is the pinnacle of marathons,” said Calamia, 26, who won the nonbinary division of this year’s San Francisco Marathon. “So to be heard by them is a sublime shift in the running community for trans and nonbinary athletes.”

The policy change immediately rippled across the sport. On Wednesday, the London Marathon added its name to a growing list of athletic events that will debut a nonbinary category. Participants will be able to register as nonbinary for its 2023 race.