Physical activity has long been considered a great noninvasive and inexpensive method of disease prevention.
In a new study published in the journal JAMA Oncology, researchers found that increasing aerobic exercise to 300 minutes from 150 minutes could reduce total body fat, and other adiposity measures, in postmenopausal women who were previously inactive during a one-year period.
The study observed 400 women with a body mass index (BMI) between 22 and 40. The women were asked to not make any dietary changes. Study results indicated that there were greater decreases for obese women when measured for changes in BMI, waist and hip circumference, weight, and subcutaneous abdominal fat. Obese women were categorized with a BMI of 30 or above.
In the 300-minute exercise group, the average total body fat reductions were one kilogram, or one percent of body fat, when compared with the 150-minute exercise group.
The Centers for Disease Control and Prevention recommends a minimum of 150 minutes of moderate-intensity aerobic exercise on a weekly basis, such as brisk walking, or 75 minutes weekly of vigorous intense exercise, like running or jogging.
Study authors from Alberta Health Services in Edmonton, Alberta commented, “These results suggest additional benefit of higher-volume aerobic exercise for adiposity outcomes and possibly a lower risk of postmenopausal breast cancer.”
Researchers note that findings are important, especially since previous studies have linked body fat with an increased postmenopausal breast cancer risk.
In the study, participants had one-on-one sessions with an exercise trainer for the first two sessions. Aerobic activity that resulted in 65% to 75% of heart rate reserve was considered acceptable for the study. Equipment used for the study included elliptical trainers, stationary bicycles, and treadmills. The trainers also included comprehensive exercise education, with technique instructions and exercise examples participants could perform at home.
The authors conclude, “A probable association between physical activity and postmenopausal breast cancer risk is supported by more than 100 epidemiological studies, with strong biologic rationale supporting fat loss as an important (though not the only) mediator of this association.”
Sources for Today’s Article:
MacGill, M., “Exercise 300 minutes a week ‘to cut postmenopausal breast cancer risk,” Medical News Today web site, July 19, 2015; http://www.medicalnewstoday.com/articles/296906.php.
Friedenreich, C.M., et al., “Effects of a High vs Moderate Volume of Aerobic Exercise on Adiposity Outcomes in Postmenopausal Women: A Randomized Clinical Trial,” JAMA Oncology web site, published online July 16, 2015; http://oncology.jamanetwork.com/article.aspx?articleid=2396584.
“How much physical activity do adults need?” Centers for Disease Control and Prevention web site; http://www.cdc.gov/physicalactivity/basics/adults/, last updated June 4, 2015.