Whether you are a 20-year-old speed demon or a 73-year-old coming off knee replacement surgery, the Colonial Road Runners want you.

“If you run a five-minute mile, you’re welcome here,’’ said club president Frank Donaghy, before quickly adding, “If you run a 15-minute mile, you’re welcome here.’’

Donaghy, 56, of Stoughton, is in his fourth year heading the club, but has been involved with it in some fashion since 1983. You might say it’s in his blood: His father, Al, of Abington, was founding vice president at the club’s creation four years earlier. Now 86, Al Donaghy no longer runs himself but remains active with the club.

From the beginning, the club, born in Abington and drawing most of its members from Southeastern Mass., has embraced runners with open arms regardless of their natural abilities. It’s a formula that’s worked, as the club has grown from a handful of runners back at the outset to some 700 today. Individual members pay $20 a year, families $30.

Right now, the club is smack in the middle of its Summer Fun Run season, a perfect illustration of its core philosophy. From May 1 through August 29, over 50 races ranging from roughly 3¼ to 3⅔ miles are staged on three courses in Raynham, Abington, and Brockton, drawing club members and other runners from as far away as Rhode Island. Races are held each week on three different weekday evenings, making it entirely possible for runners to participate in three fun runs each week.

Betsy Knapp, 73, of Weymouth, often does just that. A competitive runner for 43 years and a longtime club member and volunteer, she rarely misses a race.

“Each [fun run] is different,’’ said Knapp. “The courses are all different from one another.’’

Donaghy has known Knapp for almost 30 years and said he’s continuously amazed at her devotion to both running and the club.

“She’s like the Energizer bunny,’’ he joked.

But the irrepressible rabbit, so far as we know, never had to deal with left knee replacement surgery, which Knapp underwent four years ago.

As a result, she has had to make some adjustments.

“I can only run on flat surfaces,’’ she said. “If there is a hill on a course, I need to walk for a couple minutes.’’

But walking intervals or no, Knapp keeps at it. Asked what motivates her, she said it’s not just the unique courses but the people she meets while on them.

“They’re all unique,’’ she said, “with different people who are all my friends.’’

Even as the club retains the loyalty of longtimers like Knapp, it’s eager to attract some fresh blood.

“We are starting a kids track series,’’ said Donaghy. “It incorporates any child ages 3 to 14.’’

The first such run was held July 8 at Raynham Middle School; three more are planned for Sundays this month.

The Road Runners’ lineup includes training runs every Thursday evening at Abington High School and five club races each year at venues ranging from the West Bridgewater Senior Center to the Blue Hills Reservation. The most recent addition, the Frosty Half Marathon, is a December event over Raynham country roads.

Donaghy is always looking to incorporate new races into the mix, and his imagination seems to know no bounds. Does a taco mile sound sufficiently tasty? As Donaghy envisions that one, each racer would need to consume a taco after running each lap over a mile-long race.

But whether the taco mile ever gets off the ground, there’s no doubt this time of year that the Colonial Road Runners are out there hitting the ground running, day after day.

Joe Rice can be reached at joseph.rice@globe.com.