Running vs. Walking for Breast Cancer Survivors
Runners were less likely than walkers to die of the disease during nine-year study, but the findings aren't foolproof
"Running may be more effective in interrupting the hormone cycle and lowering estrogen in a woman's system," he said, and the lower estrogen levels mean less fuel for breast cancer to grow.
But some breast cancer experts have reservations about the study findings, including Leslie Bernstein, director of cancer etiology at the City of Hope Comprehensive Cancer Institute, in Duarte, Calif.
Although the message to exercise is a good one, the data used for the study lacks some vital information, Bernstein said.
Williams acknowledged the lack of certain data, such as the self-reporting of the participants, how advanced the cancer was at diagnosis, what type of breast cancer it was and what treatment was used.
Other factors might have influenced the findings, too, Bernstein said. For instance, the runners might have had less advanced disease than the walkers. She said she is not aware of any other studies showing such a dramatic difference in survival between runners and walkers, and she has published extensive research on exercise and breast cancer.
Her advice to breast cancer survivors? "I would say it's better to run than to walk because you spend more energy," Bernstein said. "But you can only do what's good for you. Older women will probably not want to run unless they have been running all along."
The plan to run after breast cancer treatment might be better for younger women, she said. Experts advise checking with a doctor before starting a workout regimen.
Those who decide to walk can think about doing so more briskly, with a doctor's approval. "If you walk, push yourself so you're out of breath," Bernstein said.