"They said if I had been unfit and stayed the weight I was, the heart attack I was going to have was going to kill me. Being active, it was just a small heart attack."
Mr Bulloch, an Auckland aluminium joinery salesman, took up ironman training in 2010 to turn his life around.
He weighed 120kg and was on medication to treat depression. He said that setting goals and training had made a complete change to his mental wellbeing, and he was now down to 87kg.
The heart attack was a set-back - he had to cut down on exercise for six months - but he is now back on track.
The cause of his health scare remains unknown.
"They just said I must have been susceptible. They couldn't understand it."
He had no family history of heart disease, stopped smoking five years ago, his cholesterol levels and blood pressure were fine and there was no sign of heart problems attributable to exercise.
There is emerging but controversial evidence that long-term extreme exercise causes excessive heart wear and tear.
Mr Bulloch, who now takes a daily aspirin and statin medication, chose to speak publicly to help the Heart Foundation's annual fund-raising appeal. "I was the fittest and healthiest I have ever been and I still had a heart attack. Everyone should have regular heart checks."
To donate, visit:
www.heartfoundation.org.nz
or phone 0800 830 100