"We found a moderate level of moderate intensity exercise improved physical function and controlled weight gain in patients undergoing adjuvant therapy for breast cancer, whether the exercise was supervised or done at home," says Roanne Segal, MD, lead study author. Segal is a medical oncologist and medical director of the rehabilitation oncology program at the Ottawa Regional Cancer Center in Ottawa, Canada.

Adjuvant therapy is treatment administered after surgery aimed at decreasing the chance the cancer will come back. Chemotherapy and radiation therapy are both forms of adjuvant therapy.

The researchers enrolled in the study 123 women with Stage I or II breast cancer. One-third of the women were assigned to a supervised program in which they walked briskly enough to raise their aerobic function (ability to deliver oxygen to working muscles) to between 50 and 60 percent of maximum capacity for 30 minutes, three to five days a week.

Another third of the women were instructed to follow a similar walking program at home without supervision. The final third of the women were given no specific exercise advice by the researchers, and may or may not have received any from their individual oncologists.

The researchers took various measurements of the women?s physical abilities at the beginning of the study and again six months later. After six months, the women on the supervised and the unsupervised physical activity programs functioned better physically and gained less weight compared to those not on a regular physical activity program. This held true whether patients were undergoing chemotherapy or another form of adjuvant therapy, such as radiation. Regular physical activity also improved some patients? cardiovascular function, although the study was not designed to measure the influence of exercise on cardiovascular health.

The researchers were surprised to find how few women dropped out of either the home-based or the supervised exercise programs. "Apparently, patients perceive it as a way to help control their own destiny in their fight against the disease, and are very highly motivated," notes Segal.

Segal cautions against the idea that if moderate exercise is good, more intense exercise may be better. "Anyone beginning an exercise program should first consult with someone with a background in exercise physiology, who can evaluate their level of fitness, and that holds true for cancer patients as well," she notes.

This study is the first randomized trial conducted on the role of exercise in maintaining physical function of patients undergoing adjuvant therapy for cancer.

A breast cancer expert with the American Cancer Society (ACS) says the study provides scientific evidence in line with results reported informally by some survivors. "Given the anecdotal evidence, it?s not surprising to find out that exercise provides a benefit," says Debbie Saslow, PhD, director of breast and cervical programs for the ACS.

"And most women today are going to survive breast cancer," notes Saslow. "Once they do that, they?ll want to reduce their chances of a recurrence, avoid heart disease, and deal with the other general health concerns that come with growing older," notes Saslow. "Regular, moderate exercise can help these women in those ways as well," she adds.