WALKING on a treadmill three times a week helped stroke survivors improve their mobility and physical conditioning and also led to a "rewiring" of the brain, researchers in Washington said last Thursday.

Some of the treadmill walkers achieved major improvement despite coming into the study needing a wheelchair or walker to get around, and brain scans revealed positive brain changes following six months of such exercise, the researchers said.

"Improvement can occur a long time - meaning months and years - after the stroke," said Dr Daniel Hanley, a neurology professor at Johns Hopkins University School of Medicine in Baltimore, who helped to lead the study. The findings were published in the American Heart Association's journal, Stroke.

Stroke survivors can be left with paralysis or loss of muscle movement.

A stroke can impair a person's gait, reducing mobility and fitness and promoting chronic disability.

Stroke most commonly occurs when the blood supply to a part of the brain is stopped or greatly reduced, depriving it of oxygen.

The study involved 71 patients, of an average age of 63, who had a stroke at an average of about four years earlier.

About half were selected to walk on a treadmill for 40 minutes, three times a week for six months, while the rest did stretching exercises for the same amount of time instead of using the treadmill.

In the treadmill walkers, brain scans detected increased activation in brain areas associated with controlling gait and walking, including the cerebellum and midbrain, the researchers said. No such changes were seen in the others.