The 53-year-old has been in an induced coma and on an artificial respirator at Santa Maria alle Scotte hospital in Siena since Friday.
“The third night of intensive care was spent without changes,” the hospital said in a medical update.
“His cardio-respiratory and metabolic conditions remain unchanged while the neurological picture remains serious.”
Dr Sabino Scolletta, head of critical care told journalists: “The brain needs rest. However, every passing day is a good sign despite the seriousness of the situation.”
Zanardi suffered head injuries with multiple facial factures and fears for his sight after losing control of his bike and colliding with a truck during a race in Italy.
An investigation has begun into the circumstances surrounding the accident on the ‘Obiettivo Tricolore’ stage relay race which sees participants journey across Italy on handbikes, wheelchairs or cycles.
Race director Piero Dainese said Zanardi had decided late to compete.
“Alex didn’t even have to race that stage, it wasn’t even on the programme, but he got caught up in the enthusiasm,” Dainese told La Repubblica.
“He had wanted to show that Italy could start again after COVID, even in sport. That if a group of people without legs can do it, everyone can do it.”
A former F1 driver, Zanardi has become one of the great figures in disabled sports after both his legs were amputated in 2001 following a motor racing accident on the Lausitzring track in Germany.
Zanardi raced for Jordan, Minardi and Lotus in Formula 1 in the early 1990s before switching to the CART championship in the United States where he was series champion in 1997 and 1998.
He returned to F1 with Williams in 1999 before heading back to CART.
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