text: Australia hooker Nathan Charles has spoken out about being born with and overcoming cystic fibrosis to pursue a successful rugby career. The 26-year-old, who has so far earned four international caps for the Wallabies and is in with an outside chance of making Michael Chieka's World Cup squad later this year, took part in a promotional video as part of Nutri Grain's #Unstoppable campaign. He spoke about his diagnosis with the life-threatening illness which affects the lungs, pancreas, liver, kidneys and intestine and how he used his love of sport as means of battling it. Australia hooker Nathan Charles has revealed his incredible battle with the disease cystic fibrosis . Charles took to rugby as a youngster as a way of battling with his illness and has since turned professional . Archived match footage from Charles' school days at Knox Grammar School in Wahroonga shows him excelling at rugby from an early age. In a heartfelt interview, Charles sheds light on to the daily struggles he has to overcome, but insists that he is prepared to, because he wants to be defined by his abilities on the field and not by his condition. Typically, sufferers from cystic fibrosis are not expected to live beyond the age of 17, but Charles has spent his entire life defying this disease. Charles spoke about the daily struggles that his illness presents, but insists he is prepared to work past them . Charles has earned four caps for Australia and will hope to make their World Cup squad later this year . Usually, cystic fibrosis sufferers don't live past 17-years-old, but Charles, 26, will not let his disease define him .
target: Australia hooker Nathan Charles was born with cystic fibrosis .
  He has overcome the life threatening disease to pursue a rugby career .
  Charles spoke about his experiences in a promotional video .