Researchers are trying to determine if cognitively normal subjects undergoing a moderate aerobic exercise program will accumulate less amyloid-ß (Aβ) concentration in their brain than subjects undergoing a non-aerobic exercise program, and further evaluating the safety and imaging characteristics of florbetapir F 18, the radioactive drug that will allow us to image changes in the brain amyloid-ß (Aβ).

After screening assessments have been completed, subjects will be randomized into one of two groups: aerobic exercise group and non-aerobic exercise group. All subjects will be trained on the Physical Activity Scale for the Elderly (PASE), using the Body Media armband, and exercise diary. Subjects will also complete an online food questionnaire.

Subjects assigned to the aerobic exercise group will work with an exercise trainer who will provide individual training (six half hour sessions) until they are proficient at the use of the equipment and understand goals. Subjects will return to Brooks Family YMCA at their convenience, but at a minimum of four times per week. Subjects will complete the exercise journal daily and the Physical Activity Scale for the Elderly (PASE) questionnaire on a monthly basis.

Subjects assigned to the non-aerobic exercise group will attend supervised classes on toning and stretching at a minimum of four times per week. Subjects will complete the exercise journal daily and the Physical Activity Scale for the Elderly (PASE) questionnaire on a monthly basis.

• 65 years of age or older.
• Not diagnosed with memory problems.
• Do not exercise in which you sweat and/or raise your pulse rate more than 30 minutes two times per week.
• Able to walk ten blocks (about one mile).
• Willing to participate in weekly exercise classes at the Brooks YMCA for six months.
• Able to have an MRI and CT/PET scan.

Adverse events were collected at baseline, 3 months, and 6 months.