Craig Sisterson doesn't do things by halves.
When he decided he needed to get in shape, he couldn't have set himself a bigger training goal than to do the adidas Auckland Marathon on Sunday.
The central city resident says he had "let himself go" by not having much physical activity in his lifestyle.
He spontaneously registered for the event in March as a way of motivating himself to get in shape and has lost more than 20kg so far.
"I thought: Whatever happens I will be in a much better place than I am now."
Size mattered when it came to a goal.
"I had people say: That's great but why don't you just do the half?"
He says without training he could have gritted his teeth and had a "horrible time" getting through a half, but the full 42km marathon was something that he needed a dedicated training regime to complete.
"If it was a smaller goal I would get busy at work and make excuses.
"I have had people describe me as an all-or-nothing person."
He is also working on a much healthier diet and is reaping the benefits.
"I feel fitter and I'm in a better head space."
Forty two kilometres is still "a big number" to comprehend but completing 32 on a training run recently has given him a surge of confidence.
"I'm feeling comfortable that unless something atrocious happens I will finish."
He's also raised $2700 so far for the Heart Foundation.
"I'm doing something for myself but I'm also doing something for other people which gives me a bit of extra motivation.
"When you have those moments when you might want to give up and your body is screaming at you, you think about the people who have supported you and it keeps you going."
Mr Sisterson has already signed up for another marathon in Wanaka next year.
He says he is pleased about what he has accomplished so far but there is more to do on his physical and mental journey.
"Another good reason to do a marathon is to get out of your comfort zone and remind yourself that we are all capable of doing so much more than we think."
To sponsor Mr Sisterson go to heartracer.org.nz/CraigSisterson/.
- © Fairfax NZ News