Can Exercise Improve Cancer Associated Cognitive Dysfunction?

Objective 1: Conduct a randomized trial to test the effectiveness of a 24-week aerobic exercise intervention in adult, female breast cancer survivors with self-reported cognitive changes following chemotherapy. The investigators will test the following hypotheses: 1. A) The exercise intervention will improve performance on neuropsychological tests of specific cognitive domains of executive function, namely i)selective attention and response inhibition, ii)processing speed and mental flexibility, and iii) verbal memory and learning in exercisers (EX; n=15) versus delayed exercise controls (CON; n=15). B) The exercise intervention will reduce self-reported cognitive dysfunction and its impact of function and quality of life, in EX compared to CON, measured as a decreased score on the Functional Assessment Cancer Therapy-Cognition Scale (FACT-Cog). Objective 2: Conduct analyses on the effect of the intervention on brain activation patterns using functional magnetic resonance imaging (fMRI). The investigators will test the following hypotheses: 2. A) At baseline, brain activation patterns will differ in breast cancer survivors reporting cognitive difficulties following chemotherapy compared to breast cancer survivors who have not received chemotherapy (who serve as breast cancer/no chemotherapy controls; not enrolled in the exercise intervention) during neuropsychological tests completed in the scanner. B) The exercise intervention will result in a decrease in regions of cortical activation, particularly in regions that show higher activation in breast cancer survivors following chemotherapy, compared with no change in controls.