James Cracknell, OBE (born 5 May 1972) is a British rowing champion and double Olympic gold medalist.

From Official JCracknell: On 20th July it's exactly one year since James Cracknell was seriously injured in a cycling accident in America. His helmet saved him. James has made a short film to encourage others to wear cycle helmets. To show your support, pass the film to your friends and most importantly, when you're out cycling, use your head. Use your helmet.

More about the cycling Accident from Wikipedia:

On 20 July 2010, Cracknell was hit from behind by a truck whilst attempting to cycle, row, run and swim from Los Angeles to New York within 16 days. The accident happened at around 5.30 am on a quiet stretch of road outside Winslow, Arizona. It has been reported that his bicycle helmet saved his life but he suffered a contre-coup injury to the frontal lobes of his brain. He is now back at home with his family, although recovery is expected to be still some time away.