You’re ready to get your event off the ground or take it to the next level, but besides doing absolutely everything yourself and roping in friends to help you, you’re not sure how to staff the race: How many people do you need? Should they be volunteers or employees? Where do you even find them?

“It’s taken lots of years to kind of figure it out,” said Heidi Swartz, executive director for the Cowtown Marathon and its associated non-profit, C.A.L.F., which puts on smaller local races, training programs, and kids’ events throughout the year.

One of the things she’s figured out over the years is what questions and considerations a race director needs to be asking themselves about staffing events.

That...