In Kiwi slang, to "bust a gut" means to make an intense effort.
You'll have to do just that in tackling one of the city's traditional running events in a race to the top, and back down again, of the world's steepest street, Baldwin St.
Organised by Dunedin's Hill City Athletic Club, the Baldwin Street Gutbuster is part of the Celebrate Hidden Dunedin festival.
Categories include the fastest male, fastest female and fastest primary-aged child. There are also plenty of spot prizes for participants.
Hundreds of people take on the 750m-long challenge but the record has not been beaten in more than 15 years.
It was set in 1994 by Sasha Daniels, a powerful sprinter from Hill City, in a time of 1min 56.06sec, and the two-minute barrier has proved hard to breach since.
The fastest woman is Clare Corbett, who ran 2min 54sec. The slowest runner typically takes between 10 and 12 minutes.
"Not many people can master downhill running. The legs can become like jelly going uphill and use different muscles going downhill, and people can sometimes get speed wobbles," organiser Kevin Murphy said.
If it rains, runners will only race up the hill, for safety reasons.
The event costs $5 for a person and/or family. Badges and T-shirts are available to buy as keepsakes from the occasion.
No matter how long it takes you, you are sure to walk away with a sense of achievement at conquering the steepest street in the world!What: The Baldwin Street Gutbuster.
Where: Baldwin St, Northeast Valley, Dunedin.
When: Sunday. Registration from 10am. Race starts 11am sharp.
Cost: $5.