Martin Clancy, 49, from Kilmaley, Co Clare, a member of the Dolmen Cycling Club, sustained serious head injuries after he lost control of his bike during the An Post Tour de Burren cycle race on Saturday.
He was airlifted to Cork University Hospital following the accident at Ballyella near Fanore, and underwent surgery that evening.
An Ennis-based hospital consultant, Dr Terry Hennessy, who had been taking part in the same event, was one of the first on the scene.
The alarm was raised and an ambulance sent to the scene, while the Irish Coast Guard service was also requested to assist.
Co-ordinated by staff of the marine rescue centre at Valentia, Co Kerry, the Shannon-based rescue helicopter was diverted to the incident from a training exercise in Galway Bay.
Mr Clancy was removed by ambulance to a location on the main Fanore to Ballyvaughan road, where the helicopter was able to land safely.
Dolmen Cycling Club chairman Philip Colleran said: “It appears that after finishing the first climb of the day, he lost control of his bike on a bad bend during the descent. I was gone ahead of Martin at the time but we were lucky that Dr Terry Hennessy was travelling behind and stopped straight away.
“Martin was wearing a helmet but it looks like that in the fall it may have lifted a small bit and he fractured his skull.”