Patients in the early stages of Alzheimer’s disease who performed better on a treadmill test had less atrophy in the areas of the brain that control memory, according to a study released Sunday.

Magnetic resonance imaging (MRI) showed less shrinkage in the hippocampus region of patients’ brains in the Alzheimer’s patients with higher fitness scores. In Alzheimer’s the hippocampus is one of the first parts of the brain to suffer damage.

Exercise and physical fitness have been shown to slow age-related brain cell death in healthy older adults.

The new study was released at the International Conference on Alzheimer’s Disease in Chicago. Researchers at the University of Kansas Medical Center in Kansas City, Kan., studied the connection between cardiorespiratory fitness and regional brain volume in more than 100 people over 60. About half were healthy older adults and half were in the early stages of Alzheimer’s.

In a statement, lead researcher Robyn A. Honea said the study suggests “that maintaining cardiorespiratory fitness may positively modify Alzheimer’s-related brain atrophy.”

But it isn’t clear whether exercise helped avoid brain damage or if brain-damaged people had less ability to exercise.

The study was funded by the National Institute on Aging and National Institute on Neurological Disorders and Stroke.

(This version CORRECTS that this was a treadmill test, not a study of exercise over time.)