NEW YORK, OCT 18: It sounds improbable, but Muhammad Ali says he wants to get back into the ring one more time.In this week's Newsweek magazine, the three-time heavyweight champion wrote that he is planning on getting in shape to do some sparring, despite his Parkinson's Disease that has slowed his speech and movement.Ali, 57, last fought professionally on Dec 11, 1981, a 10-round loss to Trevor Berbick. He finished with a 56-5 record and 37 knockouts.``Now I'm fighting Parkinson's Disease. But I don't let it stop me. I still travel, attend to my business, do interviews,'' Ali wrote in a first-person remembrance for the magazine.``And let me tell you something that'll shock the earth. I'm going to train and get in really good shape, lose 35 pounds (16 kg) and do an exhibition in Madison Square Garden with two or three contenders,'' he wrote.``I'll dance for 15 rounds and whup 'em. I haven't forgotten. I'll be weighing in at 210 pounds (95 kgs). I'll just say, `I am returned. Get the contract.' ''Ali travels with his wife Lonnie, who speaks on his behalf. His speech is limited by Parkinson's, a degenerative nerve disease. His walk is a little slower, but his intellect is unaffected.Ali's daughter Laila, one of his eight children, won her first professional fight on Oct 8 with her father in attendance. She plans on fighting again.In the Newsweek article, Ali called his fight with Joe Frazier in 1975, the `Thrilla in Manila,' his greatest bout. He also said the greatest thing he ever did was not go to Vietnam when drafted in 1967.