The Rock ‘n Roll Marathon is coming up in just a couple of weeks. This year’s event will be a major milestone for 47- year- old John Spangler.

That's because, last year, the race nearly killed him.

“I never thought I would ever hear the words: `heart attack.’”

See him stretching before his morning run, you’d think Spangler is the very definition of good health.

He's been a runner for 30 years and a vegetarian for nearly that long.

During the marathon last year, Spangler suddenly felt his energy slipping away but he gutted it out to finish.

He said later he felt a weird cramping in his biceps but didn't think much of it until the ride home.

“When we went to the car to drive home, I started getting a really strange burning sensation. It literally went from shoulder to shoulder. My whole chest was burning,” Spangler recalled.

Still, he said, all he wanted to do was to go home and take a shower.

Fortunately, he didn’t.

“In John's situation, that would have been a poor decision. He probably would have evolved and may have had a fatal heart attack,” said Dr. Roy Avalos, a physician at Scripps Hospital in Encinitas.

Avalos found a clot and a 40 percent blockage in one of John's arteries.

“That's the tendency. A lot of people tend to ignore their symptoms, both men and women,” Avalos said.

A year later, Spangler is getting ready for this year's marathon. He said he is more than grateful that others who were with him last year convinced him not to ignore what he was feeling.

Outside Scripps Hospital, Spangler said, “This is a very special place for me. These people are heroes. They not only saved my life, but the quality of my life.”

Health experts say different people can feel different heart attack symptoms.

The best advice, they say, is to simply pay attention to what your body is telling you.