She has run through the hottest deserts on earth, over the world's two highest mountain passes and clocked up enough miles to span the globe three times but now top ultra-marathon runner Lisa Tamati is facing a completely new challenge - trying to have a baby.
At 47, Tamati is trying to beat a different kind of clock to conceive with fiance Haisley O'Leary.
The couple have attempted IVF treatments and had a heart-breaking miscarriage after 12 weeks of pregnancy.
"I had this wonderful midwife come in," Tamati tells Native Affairs in a programme to screen tomorrow. "She said to me, 'Baby's here in the room with you, baby's spirit is with you, and just let baby go."
The runner is one of an increasing number of older New Zealand women turning to IVF treatment. According to fertility experts, one in four New Zealand women and one in five men experience fertility difficulties by their late 30s.
Young women without fertility problems have about 25 per cent chance of conceiving. But this falls to about 12 per cent at age 37 and 5 per cent at 42.
Tamati had expected to have children but her dream had not yet became a reality.
"I've always thought, Yes, I'll grow up and I'll have children. And I always wanted to have it in the perfect circumstances. You know, married with the white picket fence," Tamati said.
"I have had an interesting life but it never all came together until I met my fiance. Now it has come together and the doctors are telling me, 'You're too old.' It's just like, 'You're kidding me, now I'm ready'."
But despite the the struggle, Tamati would not give up her bid to become a mother and would "treat it like a race day".
The Taranaki woman is no stranger to challenges. In the past 25 years, Tamati has competed in races across the Sahara and Gobo Deserts, over the Himalayas, through the Australian Outback and ran the length of New Zealand in 38 days. The athlete estimates she has clocked up at least 70,000km.
Among her achievements, Tamati was the first Kiwi woman to finish the infamous Badwater Ultramarathon through the hottest desert on Earth, running 217km non-stop through Death Valley, in California.
For this new challenge, Tamati has given herself a deadline of two years to conceive. After the failure of IVF treatments, the couple are trying to conceive naturally but may consider egg donation if unsuccessful.