Exercise for Depression

Inclusion Criteria: 1. Ability to understand the purpose and risks of the study and provide signed and dated informed consent and authorization to use confidential health information in accordance with national and local subject privacy regulations. 2. Aged 18 to 65 years old, inclusive, at the time of informed consent. 3. Montral Cognitive Assessment (MoCA) \> 26 to exclude cognitive impairment. 4. Apart from a clinical diagnosis of major depression or bipolar affective disorder, the subject must be in good health as determined by the Investigator, based on medical history and physical examination. 5. QIDS scores \> 5 Exclusion Criteria: 1. Use of antidepressive medications or benzodiazepines at doses that have not been stable for at least 6 weeks prior to Screening 2. Psychotherapy that started less than 8 weeks prior to Screening 3. Any clinically significant psychiatric illness other than major depression or bipolar affective disorder 4. Transient ischemic attack or stroke or any unexplained loss of consciousness within 1 year prior to Screening 5. Any uncontrolled medical or neurological/neurodegenerative condition that, in the opinion of the Investigator, might impair treatment compliance and adherence 6. History of unstable angina, myocardial infarction, chronic heart failure (New York Heart Association Class III or IV), or clinically significant conduction abnormalities (e.g., unstable atrial fibrillation) within 1 year prior to Screening 7. Clinically significant 12-lead ECG abnormalities, as determined by the Investigator 8. Uncontrolled hypertension defined as: average of 3 systolic blood pressure \[SBP\]/diastolic blood pressure \[DBP\] readings \> 165/100 mmHg at Screening 9. History of malignancy or carcinoma, with the following exceptions: i) Subjects with cancers in remission more than 5 years prior to Screening. ii) Subjects with a history of excised or treated basal cell or squamous carcinoma. iii) Subjects with prostate cancer in situ. 10. History of seizure within 2 years prior to Screening. 11. Recent history (within 1 year of Screening) of alcohol or substance abuse as determined by the Investigator, a positive urine drug (due to non-prescription drug) or alcohol test at Screening 12. Clinically significant systemic illness or serious infection (e.g., pneumonia, septicemia) within 30 days prior to or during Screening 13. History of human immunodeficiency virus (HIV), hepatitis C virus (HCV) or hepatitis B virus (HBV) 14. Any other medical conditions (e.g., renal disease) that are not stable or controlled, or, which in the opinion of the Investigator, could affect the subject's safety or interfere with the study assessments 15. Female subjects who are pregnant or currently breastfeeding 16. Participation in another study 17. Other unspecified reasons that, in the opinion of the Investigator or Biogen, make the subject unsuitable for enrollment