Last year, an influential study examined whether breast cancer survivors with lymphedema could safely lift weights. Lymphedema, a painful and even disabling swelling of the arm, is a dreaded complication of breast-cancer surgery, especially if a woman had lymph nodes removed. Experts long thought that hefting weight of almost any kind would contribute to lymphedema in breast-cancer survivors and advised them to avoid picking up or carrying heavy purses, grocery bags, suitcases or their own children and to steer away, by all means, from formal weight training. But in last year’s study, breast-cancer survivors with a history of lymphedema who completed a slow, progressive program of weight training suffered fewer subsequent flare-ups of the condition than women who didn’t train, suggesting that weight lifting might actually combat lymphedema, not cause it.
The study, though, while suggestive and encouraging, was limited. It looked only at breast-cancer survivors who had already had lymphedema, not those survivors — a much larger group — who had not, so far, experienced the condition. Could those women also safely lift weights? Should they?
A large-scale follow-up study being published this week in The Journal of the American Medical Association provides some persuasive answers. In the study, weight training did not induce lymphedema. More fundamentally, the findings suggest that most breast cancer survivors would benefit from trips to the gym.
For the study, researchers randomly assigned 134 breast-cancer survivors to a one-year progressive weight-training program or to a nonexercising control group. The women in the exercising group received gym memberships and attended supervised sessions twice a week for 13 weeks, then continued on their own. They began by using extremely light weights, typically one pound, progressing to heavier weights in one-pound increments if they experienced no swelling. Most did not. While 17 percent of the women in the control group developed lymphedema over the course of the year, only 11 percent of the women in the weight-training group did. The results were particularly striking for women who had had five or more lymph nodes removed. (Fewer lymph nodes generally means a greater risk for lymphedema, since the nodes help to drain fluids; without them, fluids build and limbs swell.) Twenty-two percent of these women in the nonexercising group developed lymphedema, compared to 7 percent who weight trained.
The researchers were excited by their findings. “We showed that weight training is safe” for breast cancer survivors, said Dr. Kathryn Schmitz, a professor at the University of Pennsylvania School of Medicine and Abramson Cancer Center, Philadelphia, and lead author of the study (as well as the earlier experiment). “That’s an enormous breakthrough. Also, although we weren’t looking directly at whether it would be preventative” against lymphedema, “we suspect that it would be and that most” breast cancer survivors “should be doing this kind of exercise.”
The results come at a fortuitous time, because another study released this month suggests that progressive weight training in older women can confer significant and lasting benefits on mental and physical functioning. The study was a follow-up to a much-discussed experiment from last year, in which women aged 65 or over were randomly assigned to weight lifting classes either once or twice a week or to balance and toning classes for a year and then completed tests of their memory and other cognitive skills. The women who lifted weights performed notably better than those in the toning class. But researchers wondered whether the benefits would linger after the formal experiment had ended, so they returned to the women a year later, and retested them. What they found was that the women who’d lifted weights once a week in the original experiment remained significantly more active than they had been before joining the study. Presumably as a consequence, they had better cognitive functioning and had suffered 30 percent fewer falls than the women who had been part of the toning class.
Interestingly, the women who had been assigned to lift weights twice a week in the original study were now actually less active than they had been before the study and had suffered 8 percent more falls than the control group. Although it might seem that these women had disliked the twice-a-week program and subsequently quit, the researchers don’t believe that that was the case. “The participants who were in our twice-per-week program may have been less willing to switch to other forms of exercise” after the program ended,” said Dr. Teresa Liu-Ambrose,a principal investigator at the Centre for Hip Health and Mobility and Brain Research Centre at Vancouver Coastal Health and University of British Columbia, and lead author of the study. She says, from her own observations of the classes, that the women in the twice-a-week group had particularly enjoyed the weight training and when they couldn’t find any comparable programs afterward, had stopped working out altogether and their cognitive and balance skills had slipped.
The lesson is that “we need to promote strength training in older” women,” Dr. Liu-Ambrose wrote, with far more well-designed, readily accessible programs.
This is the same lesson that Dr. Schmitz sees arising from her study, with respect to breast cancer survivors. “Slowly progressive, well-supervised and medically prescribed weight training can have substantial benefits for these women,” she said, helping them to return to their former levels of activity and engagement with life, she said.
No woman should embark on a strength-training program completely on her own, though. Consult with a doctor and qualified physical therapist first. For more information about weight training after breast cancer, including how to find a personal trainer with cancer exercise certification, visit the website for the Physical Activity and Lymphedema study.