The Riesenbergers — Mitch and Drew in back, with Jenn, Kate and Alex in front — have made the Boston Marathon a family affair.

Mitch Riesenberger has run 13 Boston Marathons, part of a lengthy running career that began shortly after college when he found himself looking for a new challenge. The big day is a family affair for the Hopkinton resident, with his wife and children meeting him along the route. This year, his son, Drew, will join his father and make his marathon debut.

“I have been running for the American Liver Foundation team, and it’s really been a labor of love, and Drew and my whole family have been there on the course for all of these marathons,” Mitch said. “I wanted to give them an example of doing hard things and being able to challenge yourself. Secretly, I had hoped that somebody would join me.”

Still, Mitch said he was a little surprised that Drew decided to run the marathon this year amid a busy college life at the University of Tennessee. A former two-sport athlete at Hopkinton High School, Drew said the mental and physical challenge of running drew him to the sport.

“Running and endurance have been a niche for me because you can keep going as long as you don’t give in to what your brain is telling you,” he said. “I saw that through my dad, and a lot of the life lessons he taught to me growing up were along that theme.”

Drew will be running for Hopkinton Little League. He has had the benefit of training in Knoxville, Tennessee, where there has been no snow on the ground as he runs a hilly route that takes him along the Tennessee River and past Neyland Stadium, the home of the university’s football team.

Mitch is helping his son get ready for the day by coaching him on Boston’s challenging course, which he has run scores of times between marathons and training runs.

“Boston is a lesson every time, but he is going to know a lot about the quick start and how much trouble it can cause everyone,” Mitch said. “The course is built to trick you into thinking you can run faster than you should.”

But Mitch said there is not much advice he needs to give his son about training hard for the event.

“He is a tremendous worker,” Mitch said.

The rest of the family — Drew’s mother, Jenn, and sisters, Alex and Kate — will be along the course, as always. Mitch said he and Drew will start together and probably stick together until they see the family in the middle of Ashland. After that, Drew likely will run ahead as Mitch acknowledged that he probably will not be able to keep pace with his 20-year-old son.

“It’s a sobering thought,” Mitch joked.

Drew said his goal is to break four hours, something Mitch has done just once in his 13 Boston runs.

“Finishing sub-four hours would be something,” Drew said. “But just finishing Boston in general would be a dream come true.”

Mitch’s objectives are not based on time.

“My goal is to get there with a smile on my face,” he said.