Super-fit Olympic hero Alistair Brownlee confirmed he has had to go to hospital for the first time - to have his appendix removed.
The triathlon gold medallist, from Bramhope, near Leeds, said he was taken ill as he travelled to catch a flight to Brazil last week.
After first consulting with his doctor father Keith, he was rushed to Leeds General Infirmary, where he had to have his appendix removed in a routine operation.
Brownlee, who provided one of the most high-profile success stories of London 2012, took to Twitter to thank his father for the advice and the NHS for his treatment.
He tweeted: "Yes it was my appendix. Got horribly ill last week, went into hospital with a sore tummy and came out 2 days later. Thanks Dad and the NHS!"
He added: "Was on my way to airport en route to Brazil, trip put back a week and first trip to a Hospital instead."
Brownlee even posted a graphic surgical picture of his infected body part and joked that he might put it on eBay.
His father, who is a consultant paediatrician, told the Yorkshire Evening Post: "The whole family was absolutely delighted at the care and treatment Alistair received from the doctors, nurses and other staff at Leeds General Infirmary."
Dr Brownlee did not perform the appendectomy.