The American runner and long-jump champion has been told by doctors his condition could leave him in a wheelchair within three years, reported the paper.

``Doctors tell me I have the spine of a 60-year-old man,'' Lewis, 37, told The Sun.

The condition was brought on when the cartilage protecting the bone surfaces began to wear away due to his sporting activities, causing the bones to scrape together, inducing excruciating pain with most movements.

``I spent the best part of my life throwing an 180-pound (90-kilogram) body into the air and hitting the sand hard. What else could be expected?''

shrugged the champion, who won nine Olympic gold medals for his endeavours -- more than any athlete in history.

The athlete told The Sun of the gruelling practice jumps he endured:``pounding down the run-up, forcing myself off the board and falling into the pit. At times I could barely walk because my back was so stiff.''According to the tabloid, the athlete now finds it agonising to walk or to get in and out of the chair.

Lewis retired from athletics in 1997 and now lives in Houston, Texas, running his restaurant and devoting himself to charity work.