1. female and male participants 18 years or older and willing to provide Informed Consent 2. clinical stage 2 or 3 TNBC (estrogen receptor and progesterone receptor ≤ 10% by immunohistochemistry (IHC) and human epidermal growth factor-2 (HER2) negative (IHC 0, IHC1+, or IHC 2+ with negative fluorescence in situ hybridization)) 3. Physically able to walk independently without assistive device and able to march in place for 30 seconds without assistive device 4. Eastern Co-Operative Oncology Group (ECOG) Performance Status 0-1 5. Planned receipt of neoadjuvant chemoICI therapy (carboplatin/taxane in combination with pembrolizumab; taxane options are weekly paclitaxel or every 3 week docetaxel) 6. clearance to participate in the study by the patient's medical oncologist 7. normal bone marrow function 8. able to read/complete study forms/assessments and understand instructions in English

a) Any physical condition which hinders the ability to safely participate in exercise including: uncontrolled or symptomatic cardiac/respiratory disease (e.g. uncontrolled angina, unusual shortness of breath, congestive heart failure, symptomatic peripheral vascular disease), stroke/myocardial infarction in the past year, fragility fracture, recent or planned orthopedic surgery, or any comorbid condition precluding exercise per the treating physician b) receipt of medications known to influence immune function including corticosteroids (>10 mg prednisone equivalent), other immune-suppressive medication, or beta blockers47 c) Any infection or vaccination within the last 4 weeks d) e) Known HIV-positive participants on combination antiretroviral therapy f) concurrent participation in a therapeutic clinical trial or other exercise program g) pregnant h) medically advised to not exercise i) Unable to walk on a motor-driven treadmill for ~30 minutes at study enrollment j) Adults unable to consent k) No external catheters/drains (e.g., nephrostomy tube, foley catheter). A colostomy or Ileostomy is acceptable. l) Prior or concurrent non-breast malignancy. Those with prior cancers treated with curative intent are eligible. Participants with known (or history) of hepatitis B positive, or hepatitis C positive infection