A physiotherapist told me I might have a torn plantar fascia in my left foot. As early as 5km into the race, while going down a steep hill, I felt like someone had stabbed a knife through my left heel. If it was any other race, I would have dropped out immediately. But this was the world championships. I was wearing the red and white of Singapore. When you're at a major games for your country, you're not allowed to drop out - that's my philosophy.