Many studies have demonstrated the benefits of exercise. The latest revealed a link between physical activity and reduced joint pain for breast cancer survivors, USA Today reported.

Treating joint pain is important for any member of the population, but especially for those recovering from breast cancer. Seventy percent of women in remission take hormone medication called aromatase inhibitors, or Als, which cut the chances of relapse by 50 percent, but also can cause joint paint, USA Today reported. In fact, many women stop taking Als against doctor's orders -- some patients are prescribed 5 years of the drug -- because of their side effects, according to study co-authors Jennifer Ligibel of Boston's Dana-Farber Cancer Institute and Melanie Irwin. Their decision to end Als is even more worrying considering "it is precisely those women who get joint complaints who should remain on these medications because they are the women who are likely to have the greatest benefit," Victoria Shanmugam, an associate professor at the Georgetown University School of Medicine, told USA Today.

Ligibel and Irwin's study, presented Thursday at the San Antonio Breast Cancer Symposium, found that recovering women who followed an exercise program (2.5 hours per session and under the care of a trained professional) saw their pain scores decrease by 20 percent over one year. A control group following normal routines only reduced its pain levels by three percent during the year. Both groups were taking Als.

Women who attended more sessions, or at least 80 percent, lowered their scores by 25 percent; participation rates below 80 percent reduced scores by 15 percent, according to USA Today.

"No matter how you looked at joint pain, it got better with exercise," Ligibel said.

The benefits of exercise in breast cancer survivors have been demonstrated in several different studies, but none relating to joint pain. Ligibel and Irwin don't even understand the exact mechanisms by which their exercise program worked and caution that the program isn't effective for everyone, according to USA Today. Past research showing a link between physical activity, mood, and inflammation could partially explain their results, according to the two researchers.