Inclusion Criteria: Subjects aged between 55 and 85 who meet, at the time of entry into the study, clinical criteria compatible with probable AD according to the criteria of the National Institute on Aging and the Alzheimer's Association, under mild or DCL-Alzheimers (Folstein MMSE> 19/20, GDS 3-4), diagnosis will be performed by specialist neurologists according to standard practice. Patients should be able to perform physical activity on a cycle ergometer or treadmill and also must exist a caregiver who agrees to accompany him to the physical exercise sessions.