The Olympic countdown has started and Britain's young hopefuls are dreaming of that elusive gold medal. This first of a four part series takes a look at what it takes to succeed in the cruel world of elite sport. 14 year old high board diving prodigy Thomas Daley, 11 year old Welsh gymnast Venus Romaeo and 18 year judo fighter Ashley McKenzie are all at crucial stages in their young careers and have all been tipped to win gold at the London 2012 Olympics. But how much have they and those around them had to sacrifice for their sporting success?