"Before I knew it I had gone from 60kg to 112kg. The breaking point for me was when some workmates were going for a walk into the redwoods and one said to me 'you can't do this, you are too fat'.
"I couldn't believe it, I went to a personal trainer and two months later I had lost that much weight and got myself that fit that the same person was asking me for advice.
"Unfortunately I injured an ankle and had trouble with putting on weight again but this is another turning point for me. As part of my preparation I have just done the run in a team at the Taupo IronMaori. My ankle was hurting but I finished and we got our medals."
Ms Hedderwick says she decided to take control of her life and make some changes, partly to prove some of her detractors wrong, but she stressed this is now a personal journey and one that she is winning.
"I started putting on weight when I first moved to Rotorua and since then all I have heard is 'you are too big, you can't do it'. I was missing out because of my size.
"So I am doing this for me. The feeling of euphoria when I finished the IronMaori was amazing, despite struggling with shin splints and feeling like I was duck waddling a lot of it, I finished and my team were amazed, they thought what I had achieved was awesome."
She is not doing this alone though, calling on the support of good friend Terina Norris as they encourage each other at every step.
"I am doing this with my friend Terina, she walked the run at IronMaori and we are doing this one together and training together. We have a 21km route up through the redwoods to train on and have a route that we are taking on around town on the flat that is different to the forest so we are getting used to that as well."
Ms Hedderwick says the benefits from her increased fitness are one thing, but the spinoffs from the exercise flow into her mental wellbeing.
"I want to do more of this, I have discovered a liking for triathlon and running. I was always good at sprints, but I enjoy the time out there, I don't even take my music with me. I enjoy looking at everything and just talking to myself, it is quite relaxing.
"I know I won't win or come anywhere, but for me if it can get to the finish line and go that one minute faster than last time, I will be happy."
Like many who are attracted to the event, Ms Hedderwick is planning on enjoying the Hawke's Bay region when the hard work of the run is over.
"We are looking forward to enjoying the weekend and I have no doubt we will find something great to do after the run. It is somewhere different for me and it's where Terina grew up, so she will know all the places to go to."
Entries to the Air New Zealand Hawke's Bay Marathon are open online at hawkesbaymarathon.co.nz with entries before April 18 going into the draw to win 1000 Air NZ Airpoints Dollars.