He had severe chest pains during his regular 8km runs at least three times this year, and he should have stopped and seen a doctor at once.
But Professor Kishore Mahbubani, 67, did not. Instead, the former diplomat and now dean of the Lee Kuan Yew School of Public Policy, National University of Singapore, "kept on running, believing that determination could always overcome pain". It was a close shave.
When he finally went for several tests, doctors told him on March 21 that plaque had built up in two arteries: one was 60 per cent blocked, and the other 90 per cent.
"I was told that I had two choices: to go for immediate bypass surgery, or prepare for a heart attack," he wrote to colleagues in an e-mail.
"I only had a couple of hours to decide. Fortunately, I decided to go for the surgery which was successful."
Prof Mahbubani underwent a double coronary bypass on March 22 and is now on medical leave.
Yesterday, he told The Sunday Times that news of his heart condition took him by surprise: "I am very fit, and my family doesn't have a history of heart conditions."
In his e-mail, he had said that continuing to run and putting off his visit to the doctor were "some of the stupidest decisions I have made in my life". He added: "It is truly surprising that given the nature of my blockages, I had not experienced heart attacks earlier."
"I have now been given a new lease on life. If all goes well, I may have added a few more decades to a life approaching 70 years," he said.
He intends to give his body every opportunity to heal and recover its strength fully.
When The Sunday Times asked for permission to cite his e-mail, he agreed, adding: "I want others to learn from my mistakes. We should take chest pains very seriously."