Since his revival in a doctor's surgery and the insertion of four stents, Broadhead has survived on a daily diet of adrenaline created by cycling at least 16km on weekdays, sometimes after playing 18 holes of golf. On Sundays, he cycles 40km.
Now the grey-haired grandfather is seeking longer adventures.
This month he decided to enter his longest ride yet - the 95km option of the inaugural 125km Contact Epic Around Lake Hawea mountain bike event in April.
‘‘People who have had a heart attack should do a little more than sitting inside watching TV. I suppose I challenge myself more than others. I go up a hill and I puff,'' Broadhead said.
Three years ago, Broadhead was like many money-conscious beginners. He bought an entry level bike for $499 only to upgrade later to a dual-suspension Giant bike worth more than $2000 secondhand, on which he claims he spends more than his car.
He has all the biker's bling, including a speedo he tests himself against every day.
‘‘I love having little challenges like looking at the computer. The quickest I've done my circuit is 21 minutes. So I know when I am going faster. Most times I can do it in 22 minutes,'' he said.
He is also a bit of a gear junkie and hankers for things that are better than he has got.
‘‘When you are challenging yourself and you come up to a hill and change gear and nothing happens, man you wish you had bought the top of the range. If you don't want someone to beat you, you have to have the better gear,'' he said.
His family has been supportive. His wife Mary does not give him a hard time about his bright-red lycra and his daughter always knows what to buy him for Christmas, he said.
Broadhead was raised in Timaru, where he founded and operated a boat and caravan building and fibre-glass factory, Plystron Products, for many years.
A keen water-skier, Broadhead enjoyed many summer holidays at Glendhu Bay and it was not unusual for him to water-ski to town to buy fish and chips.
When younger, he founded 80km water-ski races at Lake Tekapo because he thought they would be fun.
After leaving Timaru, the Broadheads lived at Otematata for a few years before taking up the Wanaka Caltex service station franchise about 15 years ago.
They ran the business for five years and it was during this time Broadhead's heart condition emerged.
Broadhead said he was one of the lucky ones who had not needed ‘‘the big by-pass or big cut''.
Many others could be taking up biking to obtain better health. It was low impact, not so hard on the knees and finishing was more important than times and places, he said.
‘‘I've worked it out that for my age and my capabilities, getting into granny gear I wear myself out more doing that, than walking up the hill. I am not too proud to get off and walk up a hill and when I get on again I am refreshed and off I go,'' he said.
Since taking up his new sport he has biked to Mt Aspiring Hut and back (about 18km), done the new West Wanaka route four times, completed parts of the Central Otago Rail Trail, and explored many other areas.
Last year, he took part in the 35km Bannockburn Gutbuster, the 35km Burkes Pass to Pub ride and his longest race to date, the 80km Molesworth ride.
In the Burkes Pass ride he was hoping his helmet would disguise his grey hair as he overtook a ‘‘young lad'', but he was sprung.
‘‘He looked over at me and said ‘How old are you?' and I said ‘How old do you think I am' between puffs. I said ‘I'm nearly 70' and he said ‘Hell, I hope I can ride my bike like that when I am 70','' Broadhead said.
Next month, Broadhead intends to complete the 51km Motatapu Icebreaker before preparing for the 95km Lake Hawea challenge from Kidds Bush to the Contact Energy dam via the Hunter Valley and Dingleburn stations.
He is keen for event organisers to recognise older veteran riders with a category of their own, not because he wants to win prizes but because he wants others to realise that over-70s can complete challenges.
‘‘I find my health is better now than it has ever been. I would like to see more older guys out there . . . I ride along and say, ‘God, this has got to be good for you','' he said.