Compulsory challenges are told to teams before the race, so the teams can practise together and bond before the event.
Xrace director Tamara Hermans said the event "is a real, authentic bonding experience" and a lot of fun.
Every race is different, with different challenges varying from mental to physical ones. Ms Hermans said the event builds self esteem and develops family bonds.
''A mum can do a marathon and a child can do a triathlon, but Xrace is the only event that brings the two together.
"Teams can choose their pace and go as slow or fast as they want, completing the course is the goal."
The Xrace is appropriate for the whole family, and has a separate race called Nippers for children under 6. The Nippers race starts 30 minutes before the main Xrace.
"This is what Xrace is all about. It is an authentic bonding experience, the day a mum gets to race side by side with her son or daughter."
This year's event is being held on Friday, February 16, at Barge Park Showgrounds, with the Nippers race from 5pm and the main race from 6pm.
Families of all fitness levels are welcome, as competition is not always the focus.
Families can still enter via the event website http://www.xrace.co.nz .