He had trained in a gym for two and a-half years before deciding to give bodybuilding a crack.
"Back in July I watched the NABBA Hawke's Bay bodybuilding show at Taradale High School. I thought this was something I might like to have a go at and I really enjoyed Gisborne," Grace said.
"If everything goes well on Sunday I think I will be in bodybuilding for the long term."
There's no reason why things shouldn't go well for Grace tomorrow. He trains for two to three hours each day of the week with cardio sessions in the morning and weights in the evening.
"I like seeing the changes which can be achieved with one's body through training and diet," Grace said.
"Obviously I miss not having all the foods I like, like fast foods. But I look after my own nutrition and try to have a bit of variety ... lots of chicken."
He is a big fan of American IFBB professional Kai Greene who won this year's Arnold Classic and was second at the 2012-14 Mr Olympia competitions.
"I don't want to look like Kai. I just like his personality ... he's a nice guy," Grace said.
Grateful for the different people who have helped him with his routines and his partner, Sonja Murray, for her support, he has no idea how many other competitors will be in his class tomorrow.
"We don't find out until the day because it is confidential. All I can do is bring the best I can and then it is up to the judges."
Sticking to the confidential nature of the organisation, Grace politely declined to release any details of his routine or the music he uses.
"I would prefer to surprise people on the night."
He was also realistic about his goals.
"This is my first nationals. I'm just happy to have the opportunity to compete and get a feel of it."
Grace will be one of 25 Hawke's Bay starters in the field of 120. Hawke's Bay's best hopes for titles are Aaron Vaisigano who is aiming to retain his Mr New Zealand Physique title, Billy Belcher in men's body board shorts, Victoria Cox in novice shape and Tracy Coyle who is eyeing the women's shape title.
This is the first time Hawke's Bay will host the nationals which will involve a morning pre-judging session from 9am to 2.30pm and evening show from 4pm to 9pm.
"For the last seven years we have hosted some good regional shows so when we put our hand up for the nationals we were given the thumbs up," NABBA NZ's Hawke's Bay area representative Andrew Murray said.
During the judging round the athletes will pose their bronzed and toned physiques to compete against each other, while being judged on their shape, size, muscle definition and separation.
The evening show from 4pm to 9pm will bring the audience-entertaining posing routines from each athlete, class prize ceremonies as well as the final battle for Mr and Mrs NABBA New Zealand.