Strength, agility and overall fitness is being put to the test this weekend as 500 CrossFit athletes compete to claim the title as the best of the best.

ASB Arena has been fitted out with rubber mats, plywood and industrial gym equipment form the two day New Zealand Team National CrossFit Championship.

CrossFit East Tamaki competitor Nicola Hanna at the event today.

Mount CrossFit event organiser John Templeton says everything is going really, really good.

'We've got just over 500 competitors coming from 42 affiliates from around New Zealand.

We have competitors from the far north and from the South Island.

'We have CrossFit Wild South from Invercargill and they are hosting Ruth Horrell, who is New Zealand women's champion and competes at the World CrossFit games. She's phenomenal.”

John says the beauty of CrossFit is that workouts can be scaled to suit anyone's abilities.

'We have three categories: scaled and beginners, the masters' category which is 40 plus, then we have the elite RX category. We have a huge mixture of talent here.

'The good thing about CrossFit is you have to be good at everything. You have to be strong in all areas and you have to be very aerobically fit. There is always people with strengths and weakness but ultimately all of them are very balanced across the board.”

Around 84 84 teams of six people, three men and three women, in each team are taking part in the stand-alone competition.

'This is the best of the best right here. Ritchie Patterson who is an Olympic lifter and competitors from Shane Cameron's gym. This is the biggest CrossFit competition in New Zealand.” John says the event is attracting huge crowds.

Tomorrow will see athletes head to Mount Main Beach for a 2km beach run with a weight.