"You have to do both ... like Richard [Ussher], Braden [Currie], and Dougal [Allan] have all made the transition."
However, he said multisport racing was still his main priority and his biggest up-coming race was the Speight's Coast to Coast in February.
The Rotorua Half Ironman includes a 2km splash in Tikitapu (Blue Lake), a 90km bike ride to and from Lake Rotoma, and a 21km run next to Green Lake and Blue Lake.
Clark will be up against some stiff opposition in the men's race with the likes of Graham O'Grady (Taupo) and last year's champion Bobby Dean (Te Puke) entered, while Candice Hammond (Cambridge) will lead the women's race.
Unfortunately, Rotorua triathlete Matt Parsonage, who won the event in 2013, will not be racing as he is still recovering from injuries suffered after being hit by a car while training last year.
Organiser Shane Hooks said a record field had entered the event this year, which has been running for 17 years including 10 years in Rotorua.
He said 680 people had signed up for the half and quarter Ironman distances and that did not include late entries.
The local event has been pushed back a week this year, compared to past events, to be staged closer to Christmas.
"We try and go as close to Christmas as we can get. That's why it is so late, and the reason we go this time of year is the athletes doing Ironman New Zealand can have a week off over Christmas."
He said for endurance athletes it was critical to have breaks in between training, and most people liked to take a week off around Christmas.
"People don't get fitter training, it is all about the recovery."
The Half Ironman is based at Blue Lake and participants start from 5.45am, with a bigger group starting at 6.25am.
The winner is due about 10.45am.
