After crossing the finish line at the Winter Classic 5K last December in Cambridge, runner Mike Cramer collapsed on the pavement and died.

But that was just the beginning.

Cambridge firefighters Al Coipel and Nicole Signoretti, who were working at the finish line, rushed in with an automated external defibrillator and revived Cramer, then 57. An ambulance drove him to Massachusetts General Hospital, where he underwent surgery to treat five coronary blockages that had caused his heart attack.

On Sunday morning, Cramer and his wife, Rita, plan to run the race again. This time, they envision a jubilant scene at the finish line.

“This is sort of a celebration in honor of my re-birthday,’’ Cramer, 58, said Wednesday. “It’s a nice be alive.’’

An experienced runner and cyclist, Cramer said nothing felt amiss as he ran the 5K on Dec. 3, 2017, reaching the finish in 25 minutes and 27 seconds.

He said he drank some water and talked to a few people before “tunnel vision’’ set in.

When Rita Cramer, 60, crossed the finish line, she said her husband was already on the ground being treated.

“We were very fortunate. He literally collapsed near the EMTs,’’ she said. “He was out dead on the street. He was flat out unresponsive.’’

The scene was surreal. After rescuers revived Cramer, a crowd that had gathered broke into applause. Cramer said he heard the outpouring and saluted them by raising his fist into the air.

Then the crowd applauded even louder, he said. “It really made me feel better,’’ Cramer said.

As he was being loaded into the ambulance, Cramer revealed that his sense of humor was unscathed. He requested a celebratory, post-race beer, Rita Cramer said.

“One has to have priorities,’’ he joked.

But at MGH, Cramer got sobering news: Doctors had found five blockages in his coronary arteries. He underwent open-heart surgery the following day.

Cramer’s life had been saved. Now he wanted to resume living.

After being discharged, Cramer, a software engineer, said he went back to the office for a week, but then developed an infection and worked from home for a month.

A friend, Patrick Ward, 70, drove Cramer from his home on the Waltham-Lincoln line to MGH for follow-up appointments.

Because doctors worried Cramer could further injure his chest while riding in a car, he was under orders to sit in the back seat with a pillow strapped across his upper body.

“He would joke that it reminded him of ‘Driving Miss Daisy,’ ’’ said Ward, who drove Cramer into Boston in his red Volkswagen Golf.

He enrolled in a three-month cardiac rehabilitation program at Emerson Hospital in Concord, going twice a week to exercise and learn lifestyle changes to help his heart.

Ginny Dow, a nurse who manages the program, said some cardiac patients who were in good shape before their heart attack or heart surgery are skeptical about rehabilitation regimens. Not Cramer, she said.

“He was open to coming,’’ she said. “He wasn’t saying, ‘I don’t think I need this.’ ’’

Cramer said his heart problems are the result of poor genes and a sweet tooth that elevated his blood-sugar levels and contributed to the formation of the blockages despite a regular exercise routine.

But even in the precarious moments after he was revived, Cramer’s blood pressure and heart rate were stable, a testament to his physical fitness, said Cambridge fire Lieutenant Ian Moynihan, who was summoned to the finish line to help.

“He seemed like he was in better health than all of us,’’ Moynihan said. “He was one of the most pleasant and funniest patients we’ve ever had.’’

Cramer resumed jogging outside last February, starting with half-mile jaunts followed by walking.

In April, he ran the Spring Classic 5K in Cambridge wearing bib number 5, which race director Paul Clark said he assigned as a nod to the number of blockages in his heart.

Over the summer, Cramer and Rita traveled to Italy and France for a cycling trip, scaling Mont Ventoux, a popular destination for cyclists.

Cramer said he has experienced some setbacks during his recovery. A recurring infection required him to undergo surgery to remove the staples that held his sternum together after it was split open during the heart operation.

Antibiotics he took to treat the infection inflamed his right Achilles’ tendon, which had been a problem spot before his heart attack, he said.

“Those minor setbacks are probably a little frustrating to him,’’ said Ron Ayers, 38, a run organizer for the Waltham Trail Runners, the group Cramer was running with when he was stricken. The Cramers plan to run with the group again on Sunday.

“He always wants to get going. He’s not the sort of person to sit around and not do anything,’’ Ayers said.

Mika Tapanainen, a chiropractor in Wellesley who began treating Cramer before his heart attack, said he’s happy to see his patient return to form.

“I’m thrilled for him,’’ he said. “It’s nice to see him maintain his quality of life through a traumatic event like that.’’

By sharing his story, Cramer said, he wants to bring hope to others who have experienced a similar health scare.

“Life is meant to be lived and not to sit around. That’s what I want to communicate to people,’’ he said. “You can move on and have a grand old time, and I think you should.’’

Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her on Twitter @lauracrimaldi.