"I used to run for my life, but now I'm running for joy and to inspire kids who might be refugees or in a really bad situation like I was."

The words of American runner Lopez Lomong, a former 'Lost Boy' child refugee from South Sudan who will run in the 5,000m for the United States on Wednesday.

It has been a remarkable journey for the 27-year-old, who was one of thousands of child refugees who fled the civil war in Sudan in the 1980s and 1990s.

"One Sunday morning, rebels burst into our church in the village of Kimatong and tore me away from my mother's arms," he told the BBC.

"All our parents were begging them not to take us, but they kidnapped all the kids and took us to a training camp to become child soldiers."

"I want to bring that gold medal home because I owe it to the American people who took me in."