Michael Schumacher overcame his fear of heights by regularly jumping out of airplanes and walked away from numerous crashes during a Formula One racing career in which he dominated the sport like no other driver before him. He has also survived a serious motorcycle crash but is now fighting for his life following a skiing accident in the French Alps, just five days before his 45th birthday.
Jean-Francois Payen, head anaesthetist at the University Hospital Centre in the eastern French city of Grenoble, told a news conference: "We can say that his condition is life-threatening.
"For the moment we cannot say what Michael Schumacher's future is," he added. "We are working round the clock.
“We are trying to win time."
Schumacher slammed his head on a rock while skiing off-piste on Sunday morning in the French Alpine resort of Meribel, where he has a holiday home. Schumacher was wearing a helmet at the time but nevertheless suffered injuries to the right side of his brain.
Payen said: "We think his helmet, with the violence with which his head hit the ground, obviously helped him," the doctors said. "If he'd had a similar fall without a helmet would not have made it this far."
Schumacher was conscious after the accident but was behaving erratically when rescuers reached him; he was initially conscious as he was transported by helicopter to a local hospital in Moutiers and then to Grenoble.
However, his condition deteriorated sharply afterwards.
Neurosurgeon Stephan Chabardes said an emergency brain scan carried out on Schumacher had revealed internal bleeding and injuries including contusions and lesions. He said they had operated to treat the internal bleeding.
Doctors said Schumacher had been placed in an artificial coma but, contrary to an earlier French media report, said they had not carried out a second operation during the night and were not planning any further interventions at this stage.
His wife Corinna, 16-year-old daughter Gina-Maria and 14-year-old son Mick, who was with Schumacher when he fell, are by his bedside at the hospital in Grenoble.
Schumacher had been enjoying life since his second retirement from Formula One in 2012, including spending more time on risky hobbies such as parachute jumping and motorcycling. In February 2009, he crashed a motorcycle at Cartagena in Spain, suffering neck and spinal injuries that dashed hopes he had of making a return to F1 in that year
However, he made a full recovery and announced a racing comeback with Meercedes shortly before Christmas 2009, describing his feelings as similar to a "12-year-old skipping around the place".
The record seven-times world champion failed to add to his tally of 91 race wins during his comeback, but attracted much sympathy for his fighting spirit and never-say-die attitude.
Uncompromising, obsessed, cold, calculating and a perfectionist.
These are the adjectives probably most used to describe Schumacher from the moment he made his F1 racing debut with Jordan in 1991. A "world champion of hearts" the German certainly was not for many race fans.
He once said: "I am not the type of person who likes to show emotion except to those who know me well.
"Otherwise, I control myself as much as I can. Perhaps people don't get a true picture of who I really am."
Schumacher dominated the sport, winning seven world titles, 91 F1 races and taking 68 pole positions, more than anybody else in the history of the sport.
306 GP STARTS
On 25 August 1991, he competed in the first of 306 F1 races, the Belgian Grand Prix at Spa-Francorchamps. The story of him having to spend the night in a youth hostel with then manager Willi Weber is part of the Schumacher legend. A year later, Schumacher secured the first of his seven titles, once again at Spa.
In an era when the sport was much more dangerous than it is today, Schumacher was involved in his most serious accident during the British Grand Prix at Silverstone on 11 July 1999, when he broke a leg.
He recalled later: "Suddenly, I felt how my heartbeat was getting weaker and weaker before it stopped beating altogether, and the lights went out.
“I thought 'That must be how it is when you are on your way above'." - Sapa-dpa