Influence of Fitness on Brain and Cognition

Recent studies have shown the encouraging effects of fitness training on human cognition, and brain structure and function. Such effects are of great interest both for what may they tell us about the nature of cognitive and brain aging and also for their public health implications. This study will test the hypotheses that: 1) improvements in aerobic fitness of older adults will lead to improved performance on a variety of cognitive processes, and especially those processes that are supported by frontal regions of the brain; 2) improvements in cognitive processes due to enhanced aerobic fitness will be visible on fMRI scans, and will be similar to those of young adults; 3) improvements in aerobic fitness, over the course of a 1 year intervention, will result in increases in gray and white matter volume.

One hundred forty sedentary older adults will be recruited for this study. Participants will be randomized to an aerobic exercise intervention group, or to a stretching and toning control group. Aerobic exercise sessions will be conducted three times a week for one year, beginning at a light to moderate intensity level over the first two months and progressing to a moderate to high level for the remainder of the year. The control group will meet on the same basis as the intervention group, and will participate in an organized program of stretching, limbering, and toning for the whole body that is specially designed for individuals 60 years of age and older.

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