The sport of road running, from small-town 10-kilometer races to big-city marathons, has long supported its top athletes with appearance fees. Come run our race, and you will be paid something regardless of your performance — that’s the model. The fees are a crucial source of revenue for those swift runners who have gotten a massage and are napping by the time the main pack approaches the finish line.

But the days of being paid just for showing up may soon be ending, thanks to a recent competitor in the running world: private equity.

Competitor Group, the organizer of more than 80 high-profile events around the world, recently announced that it would no longer pay appearance fees to elite athletes. The decision by Competitor Group, which is owned by the private equity firm Calera Capital, was met with indignation and might leave some holes at the front of the pack during the fall marathon season.

As private equity groups have aggressively gained control of significant portions of this niche industry — in which race fields are ballooning with runners eager to pay top dollar to participate — the sport is discovering something that the hospital and newspaper industries have learned in recent years: when Wall Street money gains sway, old methods are often dispassionately cast aside if they do not help the bottom line.