(Reuters Health) – Weight lifting may be helpful for breast cancer survivors, a new study suggests.
Breast cancer survivors who did progressive weight lifting were less likely to have physical deterioration than those who didn’t, the authors report.
Breast cancer may lead to frailty at a younger age, which in turn increases the risk of disability or premature death, they note in the Journal of Clinical Oncology, May 11.
According to many studies and guidelines, exercising during and after cancer treatment is safe and effective, said senior author Dr. Kathryn H. Schmitz of the University of Pennsylvania in Philadelphia.
“Not just for quality of life issues, but also for physiologic outcomes, medical outcomes, psychosocial outcomes and including the functional status issue, which is not a small issue,” Schmitz told Reuters Health by phone.
Physical function is related to muscle mass, and keeping function high and muscle mass intact may make it easier to withstand chemotherapy, she said.
Between 2005 and 2008, researchers recruited 295 women with early-stage breast cancer and randomly assigned them to a weight lifting group or comparison group.
Those in the weight lifting group received a year-long YMCA membership. Twice a week for three months, those women could attend 90-minute group sessions of stretching, aerobic warm-up, abdominal and back strengthening exercises, and weight lifting exercises led by exercise professionals.
For the weights section, the women performed three sets of 10 reps of exercises like bicep curls, triceps extensions and leg presses, over time adding more exercises and increasing the weight used.
After 13 weeks of supervised sessions, the women were instructed to continue on their own using the same exercise prescription for the rest of the year.
Those in the comparison group were instructed not to change their normal amount of physical activity during the same year.
At the beginning and end of the study, the women completed physical function questionnaires about their ability to complete daily activities. The researchers used those questionnaires to identify physical deterioration.
At the one-year point, 16% of the comparison group had experienced physical deterioration, compared to 8% of the weight training group. There were no serious side effects of the weight program.
“The results make sense biologically because exercise is known to have numerous benefits and it is not surprising that it could delay the onset of physical impairments,” said Dejana Braithwaite of the University of California, San Francisco.
Braithwaite, who was not involved with the new study but is an expert on the health of women with breast cancer, added that exercise after a breast cancer diagnosis has consistently been associated with a variety of benefits, including a reduced risk of recurrence and death from the cancer.
The primary aim of the trial was to assess the safety of weight lifting among breast cancer patients at risk for lymphedema, a condition in which fluid retention causes arm swelling. The study wasn’t originally designed to test the effect of weight lifting on physical function, the authors point out – and therefore, they say, the results should be considered preliminary and not definitive.
“Improving function through weight lifting seems a promising strategy for breast cancer survivors, although it is important to confirm these results in a larger study,” as this one only included women with or at risk for lymphedema, Braithwaite told Reuters Health by email.
The current guidelines for exercise for cancer survivors include 150 minutes per week of aerobic activity plus additional strength and flexibility activity, Schmitz said.
“We advise generally two to three days of strength training per week,” she said.
Many cancer survivors do not know that they need this type of exercise, and should ideally be referred to an exercise program by their oncologists, Schmitz said.
J Clin Oncol 2015.
— Kathryn Doyle0