Acute Exercise Intervention in Reducing Breast Cancer Risk in Healthy Participants

Participants are randomized to 1 of 2 arms.

ARM I: Participants undergo a moderate‐intensity acute exercise bout over 45 minutes.

ARM II: Participants rest by sitting for 45 minutes.

Inclusion Criteria:

- Resident in greater Seattle metropolitan area (King County), Pierce or Snohomish
Counties

- Healthy

- Able to perform all study requirements, including attendance at clinic visits and
capable of responding to questionnaires and clinic and exercise facility instructions
in English

- Willing to be randomized

- Capable of providing informed consent

Exclusion Criteria:

- Pregnant in past 3 months

- Lactating

- Premenopausal women: irregular menstrual periods for the previous 6 months; no use of
oral contraceptives for the previous 3 months, no use of hormone implants or
intrauterine device (IUD) for in the previous year, no use of other sex hormones
including testosterone or other androgens for the previous 3 months

- Postmenopausal women: no use of any sex hormones (estrogen, progesterone, testosterone
or other androgens, for the previous 3 months) of any type including oral, creams,
vaginal creams or inserts, patches, implants

- Current use of any tobacco products including smoking, vaping, chew, nicotine patches

- History of diabetes mellitus, or fasting glucose fingerstick >= 126 mg/dL

- Taking any medications to treat high blood sugar such as metformin

- Personal history of invasive or in situ breast cancer

- Personal history of cancer other than breast: exceptions are non‐melanoma skin cancer
and cervical neoplasia (CIN)

- >= 2 alcoholic drinks/day

- Contraindications to exercise

- Abnormalities on screening physical that contraindicate participation

- Contraindications for entry into a research exercise program: recent (within 6 months)
myocardial infarction, pulmonary edema, myocarditis, pericarditis, unstable angina,
pulmonary embolism, deep vein thrombosis, uncontrolled hypertension (systolic > 200,
diastolic > 100), orthostatic hypotension, moderate/severe aortic stenosis,
uncontrolled arrhythmia, uncontrolled congestive heart failure, left bundle branch
block, history of cardiac arrest or stroke

- Frequent marijuana use (> 1 per month)

- Alcohol or drug abuse, significant mental illness (as assessed by study staff
impression)

- History of clotting disorders (muscle‐biopsy sub study)

- Unable or unwilling to stop aspirin or nonsteroidal antiinflammatory drugs (NSAIDs)
for 48 hours before and after the procedure (muscle‐biopsy sub study)

- Allergy to anesthetics or local anesthetics (muscle‐biopsy sub study)

- Long term use of warfarin or similar medications (muscle‐biopsy sub study)