Improving Cognitive Function Through High-intensity Interval Training in Breast Cancer Patients Undergoing Chemotherapy (The CLARITY Trial)

Inclusion Criteria: * Written informed consent prior to any study-related procedures * Women newly diagnosed (Stage I-III) breast cancer. * Over the age of 18 years; children under the age of 18 will be excluded due to rarity of disease * The effects of exercise on the developing fetus are unknown. For this reason, women of child-bearing potential must agree to undergo a pregnancy test and to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for six months following duration of study participation. Should a woman become pregnant or suspect that she is pregnant while participating on the trial, she should inform her treating physician immediately. * Will receive (neo)adjuvant chemotherapy * Speak English * Able to provide physician clearance to participate in the exercise program * Able to initiate a supervised exercise program (free from any cardiovascular, respiratory or musculoskeletal disease or joint problems that preclude moderate physical activity) * Have not experienced a weight reduction ≥10% within the past 6 months * Currently participate in less than 60 minutes of structured exercise/week * Does not smoke (no smoking during previous 12 months) * Willing to travel to DFCI for assessments (54 visits total for those who elect the exercise group with on campus training session, 6 visits for those that elect the exercise at home option, 6 visits for those assigned to the control group) * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: * Patients should not have any uncontrolled illness including ongoing or active infection, uncontrolled diabetes, hypertension or thyroid disease * Patients with other active malignancies are ineligible for this study. * Patients with metastatic disease * Medical history of coronary heart or artery disease, chronic or acute congestive heart failure or history of systolic or diastolic insufficiencies * Participates in more than 60 minutes of structured exercise/week * Orthopedic or other restrictions or contraindications to high-intensity (cycling) exercise * Have a pacemaker or any implantable device that are not MRI safe; the BWH/DFCI Standard MRI screening form * Is unable to travel to DFCI * Patients who are pregnant * Patients with claustrophobia * Subjects, who in the opinion of the investigator, may not be able to comply with the safety monitoring requirements of the study.