成人快手

Why do tennis players grunt? Is it a help or hindrance?
Former world number one Victoria Azarenka got frustrated at Wimbledon after her quarter final defeat to Serena Williams, when she had to face questions about her grunting during play. Caroline Barker has been looking at the issue and finding out about the science of grunting. Can it be a help or a hindrance?
Photo: Victoria Azarenka
Credit: JUSTIN TALLIS / Stringer (GETTY IMAGES)