For six months, the trainer for Oscar Pistorius, who is set to become the first double amputee to compete in the Olympics, did not know the runner had no legs. Jannie Brooks, who began working with the South African when he was just one of many high school runners, said he had no inkling that Pistorius was wearing a prosthesis. "At the time he started to train, it was in winter so they always had tracksuit pants on," said Brooks, who has now trained the "Blade Runner" for almost 10 years. "So we trained hard ... we did explosive training ... and only once we did one exercise and he didn't go as deep as the other guys. I said, Listen, you have to go a little deeper and he told me, Listen, that's the max I can go, and I said, Why, and he said, Alright, this is my story." Pistorius is slated to make his Olympic debut on Saturday in the 400-meter qualifying heats.