Mark Valutkevich (left) and Jim Coffey smile before starting the Tokyo Marathon in March.

Hopkinton resident Mark Valutkevich and his former longtime neighbor, Jim Coffey, are not exactly sure what inspired them to run six of the world’s premier marathons. But both can agree that the credit, or the blame, for the idea should go to Valutkevich.

“I am going to blame it on Mark,” Coffey said.

“Jim says it was my fault that we got involved in this,” Valutkevich said. “And he is probably right.”

Whatever the inspiration, the pair recently checked the Tokyo Marathon off their list, the sixth and final race in the Abbott World Marathon Majors. Only a few thousand runners in the world have completed the entire series, which includes marathons in Boston, New York, Chicago, London, Berlin and Tokyo.

The journey for Valutkevich and Coffey, who now lives in Sandwich, began by pounding the Hopkinton pavement at dawn.

“I was never a long-distance runner, and in 2009, we had two little kids at the time and I was not in shape,” Valutkevich said. “I figured running is inexpensive. I bought a pair of shoes and I set a goal to run the Boston half-marathon in 2009. If it’s physically possible, I think I pulled every single muscle in my body.”

Valutkevich, who grew up in Framingham, made it a goal to run the Boston Marathon and did so in 2010. Coffey had been running marathons since 2000 and predicted that his neighbor would not be hanging up his running shoes after just a single race. He said Valutkevich told him about the world marathon majors in 2016, and they decided to give it a try.

The pair had completed all three domestic races and the London Marathon by 2019, when the pandemic hit. They ran Berlin last September before completing Tokyo in March.

Setting aside the hometown race, each had a different favorite marathon among the other five. For Valutkevich, the best race was London, with its start in Greenwich and route through scenic countryside towns with fans packing pubs along the way.

“You could hear the town coming before you saw it,” he said. “Then you go over the Tower Bridge and finish running down the embankments by Parliament and the finish line is right in front of Buckingham Palace. The scenery was amazing and the crowds were intense. … And then we hit the pubs.”

Coffey loved his experience in the New York Marathon.

“I had the perfect day to run,” he recalled. “It was just a perfect temperature and it was sunny and my family was there with me and met me towards the finish line. It was just a nice day.”

Coffey estimated that he and Valutkevich have logged thousands of miles together over the years. He said they were dubbed the conversationalists by their running buddies because they would chat as they ran.

“I like to say we solve all the problems of the world while we are out there,” Valutkevich said. “It helps the miles go by.”

Even with the world marathon majors checked off the list, both men say they are not done running or competing in destination marathons and floated Dublin as a possible next race. Coffey now is a member of the Boston Athletic Association and said his daughters have gotten into running, even competing in the Berlin Marathon last fall. He’s eyeing running Boston again.

“That would be a fun one to do with my kids,” he said.