Introduction: The prevalence of cancer-related fatigue in women treated for breast cancer is about 30% having significant effects in reducing their quality of life. There is evidence of the presence of sleep problems and immune response. Several studies claim that physical exercise is effective during and after treatment of the disease as it improves the quality of life, cardiorespiratory function, physical functioning and symptoms of fatigue although not always found significant differences between intervention groups exercises compared with a control group. Although the results of these studies are promising, generally present methodological biases as small sample size, absence of masking, heterogeneous groups, lack of monitoring short and long term and especially lack of specificity in relation to prescribed exercise ( frequency, intensity, time and type of exercise).