You're in the classification entitled T43. What does that mean?
T43 is for double amputees below the knee on each leg. I'm missing my feet because I was born with a congenital condition known as bilateral fibular hemimelia. That means an absence of the fibular bone in each leg. When I was learning to walk, my ankles kept breaking. I had surgery at 18 months.
Do you also compete against single amputees and upper-and-lower limb amputees [both T44]?
Yes, I'm using the 100m and 200m as race preparation for my specialty, the 400m. The 400m favours double amputees [T43]. Single amputees tend to put more weight on their real leg and it fatigues quicker. Over 400m, that's not efficient.
Convicted murderer Oscar Pistorius is the defending Olympic champion in your specialist event. What are your thoughts on him, given his powerful impact on your sport?
He did a huge amount for people with disabilities. He competed at the able-bodied Games, beating out 99 per cent of the world to get there. I would never go to the Olympics and I don't think Oscar should have either because, if you work on the assumption that technology improves, it's inevitable blade runners will run faster than fully-legged runners in the next 50 years.
How do you use that technology best?
My speed is dictated by the level of technology available. At primary school, I had wooden legs with feet of wood and rubber. Carbon plates didn't exist in New Zealand but were in the US. I never knew I was fast until I got the blades, so it was a gamble. My parents always said my running impairment was due to limitations of technology, not lack of ability.
When do they wear out?
The carbon fibre works like a spring. It compresses and it's a case of energy-in, energy-out. They're pretty efficient but, over time, the carbon fibre delaminates and falls apart. When that occurs, you get less energy return per stride.
Will you tie on a new set before Rio?
You don't realise until you put on a new set of blades, then it's like, 'aaah, this feels better'. I'll put on a new set about three weeks out so I get used to them before racing. It's no different to putting on new running shoes, except mine cost a whole lot more. Each blade is about $6000. They're made in the States. Fortunately I'm sponsored by Ossur, otherwise I would never have made it to Rio.