Mr Tearle is a lifelong non-smoker and infrequent drinker who started winning masters championships as a race walker, as his age grade rivals thinned out. He was a spectator at the world champs in Brazil three years ago and again at the worlds in France last year during a trip abroad with his Britain-based "young buck" brother Donald, aged 80.
Six years ago, Mr Tearle took up an all-around weights and machine training regimen at Wai Weight Gym in Masterton, where he returned after surviving the bout of pneumonia and the heart attack last year.
Mr Tearle said his heart attack had unfolded while he was on a cruise ship with his brother. He underwent surgery in a hospital in Turkey that fitted him with two arterial stents and his recovery was thankfully swift, he said.
"I died on the ship but they brought me back with a defibrillator I was told. The pneumonia laid me up real good, as well, but I did come back. It put me in hospital for my 89th birthday and, at that age, it usually kills you. I guess you could say I'm pretty lucky actually. Yeah, pretty lucky."
Mr Tearle said his wife, who was aged 84 when she died three-and-a-half years ago, supported his sport and for years had officiated at race-walking meets. His next competitive outing could be at the Anzac Day Road Races at Dalefield Hall, he said, which is a fun run and walk event.
Mr Tearle is also an avid reader and sometime gardener, who has about 80 trees surrounding his Masterton home that demand regular attention, he said.
His gym training and race walking were vital to him making 100 years of age, he said, which was his cautious but firm expectation.
"But then I didn't think I'd have a heart attack or get pneumonia. You just never know what's going to happen.
"Your body's a delicate thing and it can get out of whack because it wears like everything else.
"That's why it's important to keep moving and stay busy you know, use it or lose it. Just get up and walk somewhere, it's that simple, and the gym gives you something to do and something to look forward to.
"If I didn't go there, I'd just be sitting in a chair. You've got to exert yourself to get some kind of reaction from it. It's a two-way street and you've got to make the effort. It's a sort of thing more or less I've always done and that's why I've lasted as long as I have I suppose. It keeps you alive and life's always better when you live it fully."