Weightlifter John Evans stunned medics with his neck power and then astonished them with his bone strength.
He underwent a series of tests after becoming a global star who lifts huge weights on his head, ranging from humans to washing machines and cars.
Instead of wearing out his body, medical analysis showed the massive stresses have improved the density of his bones.
Now an OAP, Ilkeston-based John has been found to have the bone density of an athlete just out of his teenage years.
The research was carried out at Derby University on behalf of a team from a US show led by Stan Lee, who invented Spiderman. He now scours the world for “real life superheroes.
John said: “With machinery normally used by medical experts, I underwent tests on my bone density to find it was that of a supremely fit person young enough to be my grandson.
“I found out after 20 years, normal people’s bone density decreases. But at the age of 66, mine was that of a 20-year-old athlete.
“This is because I have developed this with headbalancing so my skill has done me some good. My bones are very hard and strong.
“This is why I don’t look as if I weigh 22 stone. There’s not much fat on me, all bone and muscle, and now that has been scientifically proven,” said former bricklayer John of Awsworth Road, Ilkeston.
During the tests, John forced a 675lb weight upwards with his head, setting a world record. He said: “The expert said it was especially remarkable because I lift weights with the muscles in my neck.
“Those muscles are really only there to hold up and turn the human head, which weighs seven or eight pounds.
“Weightlifters perform their feats with the muscles in their arms and shoulders, which are made for that job.”
And his talent is more remarkable because he has only one eye and suffers from diabetes, which rules out the use of stimulants to give him sudden bursts of strength. Even sugar is a danger to him.
Grandfather John added: “I am what I am. With me you get what you see.”
After studying the results of the medical tests, Stan Lee said: “The ability to balance a car like that proves his remarkable neck muscles show him to be regarded by him as a superhuman.”
In a career spanning more than 20 years, John has set more than 30 world records and raised over £200,000 for charity. He has performed live on TV in the US, China and the UK, as well as giving inspiring speeches to millions of people.
John’s feats and the medical tests will feature in the Superheroes video which is being distributed around the world.