Regular exercises reduce breast cancer risk in post-menopausal women, a research suggests.

A study found that post-menopausal women who exercise regularly for four years cut their risk of invasive breast cancer.

Previous studies showed that staying physically active and working out regularly can bring down breast cancer risk in women of all age groups by 12 percent.

This study explored how quickly the discontinuation of exercises can result in increased risk of the disease. Researchers surveyed 59,308 women enrolled into an 8-year-long cancer study conducted in France. The team noted that 2,155 were diagnosed with breast cancer.

Researchers found that the rate of the diagnosis was 10 percent less in those who worked out regularly for four years post menopause. But, such was not the case in those who exercised regularly five to nine years previously but had discontinued.

The team stated that these results were independent of body mass index, weight gain, waist circumference, and the level of activity from five to nine years earlier.

 "It was not [previously] clear how rapidly [the link between exercise and cancer risk] is observed after regular physical activity is begun or for how long it lasts after regular exercise stops. Our study answers these questions. We found that recreational physical activity, even of modest intensity, seemed to have a rapid impact on breast cancer risk. As a result, postmenopausal women who do not exercise should consider starting because their risk of breast cancer may decrease rapidly," said Agnès Fournier, PhD, a researcher at the Institut Gustave Roussy in Villejuif, France, who helped carry out the research.

The study was published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.