Shortland Street star Pua Magasiva's triathlon challenge

Pua Magasiva plays Vinnie Kruse on Shortland Street. Photo / supplied

Shortland Street star Pua Magasiva is ready to take on his first triathlon -- he's been training for seven years.

The 34-year-old Healthy Living ambassador for the Sovereign Tri-Series has been a qualified personal trainer since 2007 and said fitness was a passion.

"It's a challenge and I love challenges ... I've never done a triathlon but anything you decide to do you have to do wholeheartedly," he said.

"That was the mentality I had when I decided I wanted to do it because I love things that are hard. In this world you don't get through things the easy route, you've always got to take the hard route."

Magasiva said his training regime echoed his daily life -- never stopping.

"I never stop training, that's just the way it is," he said.

The father-of-one runs a fitness group for friends every Sunday morning because he wants to see people achieve their health goals, he said.

His top tips for a healthy lifestyle are to keep training simple in the beginning, remember that good things take time, eat vegetables, stop overeating and stay away from sugar.

"I believe in fitness, people are always looking for a quick fix, but realistically, how long is that going to be sustainable until you understand and realise that it's a lifestyle thing and if you really want to change, you've got to change for the rest of your life," he said.

The Sovereign Tri-Series takes place in Takapuna on February 13-14.