"Normally I don't thank God for these type of things as I believe God has more important stuff to worry about," he told NBC television. "But today is too much. I had to raise my eyes and thank him.
"I feel very lucky, I feel my life is a never-ending privilege."
Zanardi, a two times champion in the U.S.-based Champ Car series that is now IndyCar, competed in 41 grands prix between 1991 and 1999 with his final season at Williams.
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He had both legs amputated above the knee, with his heart stopping seven times as he lost all but a litre of the blood in his body, after the horrific crash at the Lausitzring in Germany on Sept. 15, 2001.
The Italian was leading the race when he lost control of his Reynard-Honda in the final laps and Canadian Alex Tagliani ran into him at more than 350kph.
"The car broke into two pieces, one bit of me stayed with the car and the other bit, which was my legs, went 'arrivederci' in the other direction," he said before competing at the London 2012 Games.
Zanardi, who had been read the last rites, returned to racing a year and a half after the accident and competed in the world touring car championship until 2009, by which time he had taken up hand-cycling.
Two years after the accident, he returned to the Lausitzring and finished the 13 laps that he had failed to complete during the race.
(Reporting by Alan Baldwin in London, editing by Toby Davis)
