Can you slash cancer with a set of free weights? Certain workouts are proving to protect women from breast and lung cancers, says new research

By Charlotte Hilton Andersen
June 04, 2015
Corbis Images

Working out with weights may do more than just build beautiful muscles. While all types of exercise substantially reduce your risk of both breast cancer and lung cancer, according to two new studies presented this week at the annual meeting of the American Society of Clinical Oncology, women who work out vigorously-incorporating a variety of weights and cardio several times a week-reduced their risk of lung cancer by one-third and breast cancer by 30 percent. Even better, fit ladies saw these benefits even if they had other risk factors for the cancers, like a smoking habit or being overweight. (Exercise by the Numbers: 12 Reasons to Get Moving.)

The question researchers are trying to answer now? Why exactly exercise can fend off cancer-and just how much you need to sweat to see the benefits.

One potential explanation: Exercise may reduce the number of fat cells that produce estrogen, a hormone which in excess has been shown to fuel breast cancer, Jyoti Patel, M.D., spokeswoman for the American Society of Clinical Oncology, said in a press release. (See: 6 Things You Don't Know About Breast Cancer.) And it appears that strength exercises like squats, bicep curls, and chest presses may be particularly good at this. A 2012 Harvard study found that muscle-strengthening exercises cause the body to produce a hormone called irisin, which then travels through the body and alters fat cells in a way that speeds up the metabolism, ultimately burning more calories.

For lung cancer, the explanation is a little less straightforward, said Ange Wang, M.D. student and the lead author of the Stanford paper. "Physical activity might specifically help the lungs by improving lung function and limiting the deposition deep in the lungs of inhaled cancer-causing agents," she noted. Wang also added that exercise boosts the immune system and helps people lose weight-things that have shown to protect against cancer.

Both research teams also noted that the more minutes a woman spent exercising, the more protection she had against cancer, regardless of the type of workout or other risk factors. In the studies, the women exercised an average of four to seven hours per week. And any level of intensity can help: "Our research seems to indicate that you don't have to kill yourself," Wang said. "It doesn't need to be strenuous. You just have to put the time in." (Although sweaty sessions do help protect you from other forms of cancer: Can Cardio Workouts Ward Off Cancer?)

So if you want to have a beautiful, healthy chest inside and out, think about incorporating weight lifting and other muscle building exercises into your routine. We recommend starting with the basic pushup-not only will it lift and define your chest muscles (and core, back, and arms!) but it can also help build a body suited to protect you from disease.