The results were presented July 3 at the 18th UICC International Cancer Congress in Oslo, Norway.
First randomised trial
Funded by the United States' National Cancer Institute, the study is the first randomized clinical trial to assess the effect of exercise on blood estrogens in postmenopausal women.
The study included 173 women between the ages of 50 and 75 years who were previously sedentary, overweight or obese, and not taking hormone- replacement therapy. The women were recruited from the Seattle, area. The women were carefully screened for eligibility and were assigned at random to either a moderate-intensity aerobic exercise group or a stretching control group. The exercise group exercised 45 to 60 minutes, five days a week, for a year. The control group met weekly for a 45-60 minute stretching class for a year.
The exercise program consisted of facility-based and home exercise. The participants met three times a week with an exercise physiologist at an exercise facility, where they performed treadmill walking and stationary biking. They also exercised two days a week at home, doing exercises of their own choosing, mostly walking. The exercisers were highly adherent to the exercise intervention: 81 percent of the exercisers completed 80 percent or more of their prescribed 225 minutes per week of exercise. Adherence was lower at 12 months than at three months. After one year, cardiorespiratory fitness increased by 13 percent in exercisers, and by less than 1 percent in controls.
Decrease in level of estradiol and estrone
At the beginning of the study, there was a strong, statistically significant correlation between body size and levels of estrogens: heavier women h
Contact: Hanna Hanes
Norwegian Cancer Society