Women at high risk for developing breast cancer-related lymphedema may safely lift weights without increasing their chances for developing the condition, a recent study shows.
The findings from the clinical trial, called PAL (Physical Activity and Lymphedema Trial), address uncertainty over the dangers of weight-lifting among women who undergo lymph node surgery for breast cancer. They were announced at the 2010 San Antonio Breast Cancer Symposium and published online in the Journal of the American Medical Association.
Women who have breast cancer surgery are at risk for lymphedema, a chronic condition in which too much lymph fluid collects in tissues and causes swelling. Those who have axillary lymph node dissection (surgery to remove multiple nodes from the armpit) are at higher risk than women who undergo sentinel lymph node surgery, which removes only the first one to four lymph nodes where cancer is likely to travel. Between 5 and 47 percent of women affected by breast cancer develop lymphedema at some point in their lives.
Typically, women are told to avoid heavy lifting on the sides affected by surgery. But fear and worry about lymphedema prompt many women to stop using the at-risk arm completely. The arm becomes deconditioned, when the muscles weaken so much that they become vulnerable to injury and overuse. Instead of protecting the arm, deconditioning may increase the risk of lymphedema.
The PAL trial studied the safety of exercise and weight-lifting among women at risk for lymphedema. A secondary goal was to see whether these methods decrease the chances of developing lymphedema. At San Antonio, researchers presented findings from the weight-lifting portion of the study.
Structure of PAL Trial
Researchers recruited 154 women from the Philadelphia area who were at risk for developing lymphedema. The participants were one to five years from a diagnosis of early-stage breast cancer and had at least two lymph nodes removed during surgery. They had not lifted weights in the previous year.
The women were randomly divided into two arms (groups). Participants in the treatment group received a yearlong gym membership. For 13 weeks, the women met twice weekly with a fitness trainer for 90 minutes of guided weight-lifting. Afterward, the women lifted weights twice each week on their own, using dumbbells and resistance machines. When women successfully performed all exercises for two sessions, the weight was increased by the smallest possible amount. Trainers called women who missed workouts and instructed them on ways to rebuild arm strength.
Participants in the control group received the standard treatment of no structured weight-training. They continued exercising as they had before the study. After the trial, these participants also received a yearlong gym membership and 13 weeks of supervised training.
All fitness trainers completed training in lymphedema prevention, exercise, symptoms and treatment. Participants who developed lymphedema received care, education and garments.
After one year of follow-up, 11 percent of women in the weight-lifting group had symptoms of lymphedema compared to 17 percent in the control group. Lifting may protect the body from infection, inflammation and injury by slowly training the muscles to adapt to stresses, the researchers explained.
The authors concluded that women who have lymph nodes removed may safely engage in supervised weight-lifting of 1 to 2 pounds, slowly increasing weight as they grow stronger.
A sub-analysis of 94 participants who had five or more lymph nodes removed showed that 7 percent in the weight-lifting group developed lymphedema symptoms versus 22 percent in the control group. This suggests weight-lifting may reduce the incidence of lymphedema in women at very high risk (women who have five or more lymph nodes removed), but the analysis is too small to change practice. The researchers encourage future research into this important question.
What the PAL Study Means for You
You and your doctors can feel more confident that lifting light weights will not increase your chances for developing lymphedema. It may, in fact, protect you by strengthening your muscles.
It is important to remember that study participants received more than three months of supervised training from fitness specialists with expertise in lymphedema. The women worked out regularly, and phone calls from their trainers helped keep them on track.
Talk with your doctors before surgery, if possible, about seeing a physical therapist or other fitness provider who works with women with breast cancer. Your trainer will help you determine how much weight you can lift and slowly increase the weight as you grow stronger.
If you already have lymphedema or want to learn more about safe exercise and lymphedema risk, visit the website of the National Lymphedema Network or download a copy of our Guide to Understanding Lymphedema.
K. Schmitz, et al. Weight Lifting for Women at Risk for Breast Cancer-Related Lymphedema: A Randomized Trial. Published online in Journal of the American Medical Association, December 8, 2010.