Under pressure: why athletes choke

What makes an elite sports star suddenly unable to do the very thing they have been practising for years? And is there anything they can do about it?

Scott Boswell stood at the start of his bowling run-up, immersed in his own very public hell. It was the final of the Cheltenham and Gloucester Trophy in 2001, which should have been the highlight of his cricket career. Instead, he found himself unable to do what he had been doing his entire life.

I became so anxious I froze. I couldn't let go. It was a nightmare," Boswell recalled. How can I not be able to run up and bowl - something that I've done for so many years without even thinking about it? How can that happen? What's going on in my brain to stop me doing that, and to make me feel physically sick and anxious and that I can't do something that I've just done so naturally?"