A popular gym instructor and trainer has died after collapsing while out running with his children.

Joe Houpapa, 40, a fitness trainer of world-renown at Les Mills, died in the early hours of Tuesday morning, after hitting his head on Sunday afternoon.

At Les Mills Victoria Park, in central Auckland, Mr Houpapa taught Combat and Body Pump, and was a boot camp instructor and personal trainer.

Victoria Park club general manager Jackie Marshall said the father-of-four fell and hit his head while out running with his two primary school-aged boys, Le Bron and Luca, about 4pm on Sunday.

"He was out with some of his children, out jogging. We don't quite know what happened. He suffered a massive head trauma through the fall but nobody knows what caused the fall," she said.

It was unclear if a medical condition may have contributed to the fall or if Mr Houpapa just tripped.


Post-mortem results would hopefully solve that riddle, Ms Marshall said.

He was jogging behind his two boys, and when they turned around their dad was on the ground, she said.

Mr Houpapa is also survived by his partner Trish, teenage daughter Kiana and preschool daughter Eden.

His OldFriends page states that he studied at Titahi Bay Intermediate and Mana College on the Kapiti Coast, north of Wellington. But he had been a trainer at Les Mills for 20 years, Ms Marshall said.

"He's also instructed and taught instructors for Les Mills internationally. He's probably one of the most loved [trainers] around," she said.

"It was his passion. There were two things in his life that were his passions - that was Les Mills and his family. He was a proud dad."

The family were "absolutely devastated", Ms Marshall said.

Mr Houpapa was farewelled at a memorial service in Avondale yesterday morning, before his body was taken to Taupo to the family marae.

The gym had set up a Givealittle fundraising page for his family on Tuesday afternoon, Ms Marshall said, which this morning had already raised about $36,000.

"The face of personal training and Les Mills bootcamp ... His absence will be sorely felt by all his colleagues, clients, and members of Les Mills," the page said.