Influence of Fitness on Brain and Cognition

• For sedentary older adults, no physical activity during the last 6 months; for young comparison sample, moderately active lifestyle and ability to perform exercise
• Personal physician's examination and consent to participate in testing and exercise or control intervention
• Successful completion of graded exercise test without evidence of cardiac abnormalities or responses
• Adequate performance on the Pfeiffer (1979) Mental Status measure
• Corrected (near and far) vision of 20/40 or better
• Right-handedness
• Intention to remain in the local area during the study period

• For sedentary older adults, physical activity on regular basis (twice or more per week) during the last 6 months; for young comparison sample, sedentary or highly active/athletic lifestyle
• Any physical disability that prohibits mobility (walking), stretching, and other movement
• Geriatric Depression Scale score indicative of clinical depression
• Presence of implanted device such as cardiac pacemaker or autodefibrillator; neural pacemaker, aneurysm clip in the central nervous system (CNS); cochlear implants; metallic bodies in the eye or CNS; any form of wires or metal devices that concentrate radiofrequency fields
• Left-handedness
• Individuals with chronic inflammation (for example, severe arthritis, psoriasis, inflammatory bowel disease, asthma, polyneuropathies, lupus)
• Intent to move or take a vacation longer than 1 month during the study period

Recent study findings have shown the positive effects of fitness training on human cognition, brain structure, and brain function. This study will test three hypotheses:

• Improvements in aerobic fitness of older adults will lead to improved cognitive processes, especially those supported by brain's frontal regions.
• Improvements in cognitive processes due to enhanced aerobic fitness will be visible on functional magnetic resonance imaging (fMRI) scans and will be similar to those of young adults.
• Improvements in aerobic fitness, over the course of a 1-year intervention, will result in increases in gray and white matter volume.

Participants will be randomized to either an aerobic exercise (intervention) group or to a stretching and toning (control) group. Aerobic exercise sessions will be conducted three times a week for 1 year, beginning at a light to moderate intensity level during the first 2 months and progressing to a moderate to high level for the remainder of the year. The control group will meet as often as the intervention group and will participate in an organized program of stretching, limbering, and toning for the whole body.

During this time, participants will exercise, keep a daily exercise log detailing distance walked, time spent in aerobic activity, degree of intensity (rating of perceived exertion), and general feelings during exercise, resting and exercise heart rates. Participants will participate in MRI/fMRI, physiological (cardiorespiratory), and psychosocial testing prior to beginning fitness training, after 6 months of training, and at the end of 1 year.

University of Illinois at Urbana-Champaign

• National Institute on Aging (NIA)