It was unusual, as birthday presents go: When their Ironman competitor pal turned 30, a group of friends in New York City hired an elite distance runner to take him on a workout, flying her in from Arizona for a showdown on a Manhattan track.

Standing near the starting line of the East River Park track on a recent wiltingly hot Saturday morning, Dan Goldberg, the mastermind behind the gift for his friend Rob Brink, beamed in anticipation.

“It kind of feels like a present to ourselves, after all these years of having him beat us,” Goldberg said as Brink, a business school student at Cornell, tentatively toed the line with Sara Slattery, 33, a national champion distance runner. Looking on approvingly, Goldberg indulged in the playful ribbing that characterized the occasion, deadpanning, “Happy birthday, Rob.”

The event was laced with good-natured competition, underpinned by one delicate question: Would a fit male distance runner prevail against one of the top women in the sport? Given that women are on average slower than men, matchups like this are complicated. In the running community, if a woman beats a man it is known as being “chicked.”