"I started getting pretty stressed when I heard it coming up beside me as I knew it was way too close. Fortunately, I landed on the pavement. If I had fallen the other way I could have been crushed by other vehicles."
Harrison called on Auckland sports psychologist Sara Chatwin to help him overcome his fears and get back on the road. "It was very difficult getting my head around not training when it had been such a massive part of my daily life."
After five months of gruelling rehab, Harrison will be back in action next Saturday. He will race alongside colleagues at the Tough Guy and Gal Challenge at Palmerston North.
"It was really important to have positive people around me and Sara talked through some of my rehab stresses. I didn't realise how much energy I was using up stressing and moaning about my injury, so I nipped that in the bud."
Chatwin, impressed by Harrison's determination, said: "Josh had to quickly come to terms with the accident, rehab and new training regimes and I am pleased with the way he has responded."
Harrison was so determined to get back into competition he had another crack at the Sky Tower Challenge in May and won it in record time for the second year in a row. "I was okay doing the stair climb because when I was going up I wasn't putting too much pressure on the leg, even though I was carrying a lot of equipment.
"I still wasn't fit enough to run properly, but I am now. I will be out to win the Tough Guy challenge with the firefighters."
Harrison plans to compete in October's Ironman World Championship in Hawaii.