Effect of Exercise on Sex Hormones in Postmenopausal Women

The goals of the study are to examine the effect in postmenopausal women of a one-year moderate intensity exercise intervention, as compared with a sedentary pattern (low-level stretching program), on: serum estrogens, androgens, sex hormone binding globulin, insulin, triglycerides, glucose, aromatase, FSH, LH, as well as parameters of body fat mass.


Eligibility Criteria:
Inclusion Criteria:

* Ages 55-75 years at first group meeting
* Physically able to undertake a moderate exercise program
* Sedentary activity pattern (exercising \< 2 times/week for 20 minutes at a level to produce sweating)
* Postmenopausal (not experiencing menstrual periods for the previous 12 months or FSH \>30 mIU/ml; for women who have had a hysterectomy, an FHS \>30 mIU/ml will classify them as postmenopausal)
* Body Mass Index (BMI) greater than 25.0
* Able to follow directions and fill out questionnaires, and exercise diaries and logs in English
* Agrees to be randomly assigned to either the exercise intervention or control group
* Gives informed consent to participate in all screening and study activities
* Able to come to the FHCRC for clinic visits and classes, to the UW Medical Center for CT scans, and to the UW NETT for measurements and instruction

Exclusion Criteria:

* Plans to leave Western Washington within the follow-up period
* Using hormone replacement, tamoxifen, or oral contraceptives in past 6 months
* Currently having severe hot flashes (that might prompt participant to start hormone replacement therapy before the end of study)
* Current unstable thyroid disease or unstable dose of thyroid medications or TSH \>5.0 IU/ml or \<0.5 IU/ml
* Invasive cancer in the past 10 years (except nonmelanotic skin cancer)
* Any other endocrinologic abnormality
* Breast, endometrial, ovarian, or melanoma cancer or carcinoma-in-situ at any time
* Morbidly obese (BMI \> 40)
* Current or planned use of corticosteroids
* Currently on or planning to enter a structured weight loss program or to take diet drugs
* Current use of certain other medications, such as any likely to interfere with adherence to an exercise program or likely to interfere with study outcomes
* Moderate to high alcohol intake (more than 2 drinks per day)
* Current smoker
* Diabetes mellitus (fasting hyperglycemia)
* Abnormal screening labs (hematocrit \< 32 or \> 48, white blood cells \< 3.0 or \> 15.0, potassium \< 3.5 or \> 5.0, fasting glucose \> 140, creatinine \> 2.0), or abnormalities on screening physical judged by study physicians to contraindicate participation in an exercise program
* Contraindications for entry into a training program118 including: unstable angina, uncontrolled hypertension (systolic \> 200, diastolic \> 100), orthostatic hypotension (\> 20), moderate/severe aortic stenosis, uncontrolled arrhythmia, uncontrolled congestive heart failure, third degree heart block, pericarditis, myocarditis, pulmonary/systemic embolism within the past 6 months, thrombophlebitis, ST displacement \> 3 mm at rest, history of cardiac arrest)
* Contraindications for exercise testing118 including: recent (within 6 months) cardiac event (MI, pulmonary edema, myocarditis, pericarditis), unstable angina, uncontrolled arrhythmia, third degree heart block, left bundle branch block, acute congestive failure, recent (within 6 months) pulmonary/systemic embolus, severe electrolyte abnormality
* Meets criteria to stop screening exercise test118 as decided by overseeing physician (Dr. Schwartz or McTiernan)
* volunteering in order to lose weight
* alcohol or drug abuse, significant mental illness (as assessed by study staff impression)