"I was diagnosed with Parkinson's just over two and a half years ago. Once you get that, the reality sets in about the medication and the long-term impact for the rest of your life. You have to come to terms with that and you go through a bit of a sulking period.
"After that I decided to take the bull by the horns. After doing some research the only thing I can do to really look after myself is by eating well and keeping yourself fit and healthy."
A turning point for him was getting into boxfit training.
"They started running a course in my home town so I got into that. It was a bit of a shock. I lasted about 12 minutes the first night and it has taken about 16 months now where I can endure the full hour of boxfit.
"I am personally making significant progress and believe if you are prepared to work hard, really hard, at maintaining your balance, co-ordination, flexibility, strength, general motor skills and a positive outlook on life, you also make significant gains in your quality of life."
Bennett set up the Parkinson's Tinman Club 2017. He is delighted to have 40 supporters involved who will compete at the Tinman in an individual race or as part of a team.
"Once I started talking to people they put their hands up and said 'yeah, I'm in'. Saying no was not an option," Bennett said.
"The person travelling the furthest to be with us is my brother from Whangarei, our two daughters and son and son-in-law are all involved, staff on our farm and friends."
Bennett's daughter Stephanie has played a key role in recruiting people to join the support network and she will do the longer, standard distance triathlon.
"It is pretty cool to be honest," she said. "He is one of the most positive people I have ever met and he just finds a way to make it work. I am pretty proud of him. Inspiring, without a doubt.
"I said to him on Father's Day, thank you for motivating me to motivate you, which is motivating everyone else."
Information: www.tinmantri.co.nz
Donate: https://givealittle.co.nz/event/parkinsonstinmanclub