Wanganui mums Margaret Tyson and Liz Smith choose to drag themselves through mud pits, scramble up and down obstacles, climb giant spider web nets and crawl under barbed wire "just for a bit of fun".
The close friends compete in mud runs because they like the challenge ... but what they love even more is "beating all the men".
Both recently competed in the 6km Tough Guy Tough Gal Challenge in Wainuiomata and took out first and second place in the women's 40 years and over category.
Smith, 52, was first with 48-year-old Tyson close behind.
"It feels really good to be in the 40 years and over group and still be winning at 52," said Smith.
Last year, the pair placed in other Tough Guy Tough Gal Challenges throughout New Zealand. They love to compete against each other but don't take it too seriously - "it's all just light-hearted fun," said Tyson.
The Wainuiomata course was "similar to an army assault course" set in native bush trails with a range of natural and man-made obstacles where the women battled it out with 800 other competitors.
"You had to pull yourself up ropes, over cargo nets and through electric wire," Tyson said.
Crawling through chest-deep mud pits had been one of the most challenging obstacles. "Sometimes they just suck you in and you can't get out," she said.
However, if one person gets stuck in the mud other competitors usually stop to help get them out, says Smith.
Another hard task was running up a steep hill and using ropes to pull herself up.
"It's really, really hard when you're in anaerobic debt, when you're puffing and blowing and you've got to pull yourself up this hill," said Tyson.
Smith found the electric wires hardest to conquer. "I hate going under those and getting a good zap in my back."
To prepare for mud runs, the two friends run the trails at Harakeke Forest or go on bike rides together. Their next Tough Guy Tough Gal Challenge is in Rotorua on August 23.
But playing it dirty isn't the only thing Smith and Tyson are good at.
Smith participates in gymnastics, rowing, swimming, tennis and roller skating while Tyson is a triathlete, cyclist and swimmer, and as a Masters athlete she has represented New Zealand in the 2009 Triathlon Age Group World Championships.
The pair plan to compete in the 2015 Masters Games in Wanganui in their favourite sports and Smith said she'll also be "partying hard" in the Games tent for 10 nights, with or without Tyson.
"Margaret might need to take a break throughout the week."
Jessica Tyson is an AUT journalism student on work experience at the Chronicle