just a small amount of exercise improves survival

The Nurses’ Health Study (NHS) showed that women who engaged in more than 3 Met-hours per week (e.g., walked the equivalent of one or more hours per week) had 40% lower risk of dying from breast cancer and 35% lower risk of death from any cause.  The 10-year survival for breast cancer survivors who engaged in more than nine Met-hour/week of moderate exercise was 92% vs 86% for those who exercised less than three Met-hour/week, a 6% absolute survival benefit (1).

You can read more about this study by reading the excerpt from our book here under "resources" # 24.  http://www.newlifeaftercancer.org/resources/a_prescription_for_wellness_health_behaviors_that_improve_breast_cancer_out/24_chapter_2_the_data_the_nurses_health_study/