Moderate exercise may hasten Alzheimer’s if done regularly after diagnosis, a new study suggests.

Oxford researchers found people with mild to moderate dementia who worked out in a gym twice weekly for up to 90 minutes saw their condition decline more quickly than peers. Although authors noted the differences were slight, they suggested moderate- to high-intensity workouts be nixed as treatment for Alzheimer’s.

“The exercise improved physical fitness in the short term, but this did not translate into improvements in activities of daily living, [or] health-related quality of life,” the study found.