A Chinese university professor is addicted to doing press-ups on upturned chopping knives.
Xie Guanghai, 57, a physics professor in Luoyang, says that after four years of practice he has calluses on his palms thick enough to take the blades, which are fixed into place on a wooden board.
He currently holds a world record for doing 6,012 press-ups in a row and is now trying for another for doing them on knives.
He said: "Along with the growing of my interest in this unusual exercise, the calluses have grown thicker and thicker.
"Four years ago I started to try these blade push-ups after watching a TV programme where a folk artist climbed up a ladder made of blades.
"Hopefully I can achieve the record of doing the most push-ups on blades."