Patients and staff from 60 hospitals joined in the first Sir Jimmy Savile Big Mile Walk, in support of the Royal College of Radiologists's X-appeal at 42 locations across the country.
The appeal hopes to raise pounds 5m, to be split between the college and local hospitals.
Sir Jimmy, who underwent a quadruple heart by-pass operation less than three weeks ago, spoke after leading home a group of about 60 walkers in Roundhay Park, Leeds.
"It's a good warm up for the Great North Run in about four weeks time," he said.
Cardiologist Alistair Hall was among those Sir Jimmy beat.
Dr Hall said: "He's making good progress and is ahead of schedule, we couldn't keep up with him. It's possible he could take part in the run."
Sir Jimmy paid tribute to Diana, Princess of Wales.
"I have known her for 15 years, she was a close friend. "It's a dreadful thing to happen." he said.Reuse content