The purpose of this research is to find out whether training at different exercise intensities reduces the risk of developing cardiovascular disease (CVD) to a different extent. Heart attacks and stroke are the leading cause of death in older women. Reduced variability of the heart rate and increased dips and swings in blood pressure are risks factors that predict the chance of developing CVD as are increased levels of clotting protein fibrinogen and plasminogen activator inhibitor 1, and high levels of LDL-cholesterol (>160mg/dl). We will be measuring all of these risk factors and any changes in your body fat level before you start training and after 15 and 30 weeks of training in the form of walking. At the present time the effects of exercise intensity on these factors are not well understood. This study will add to the basic understanding of these issues and allow us to recommend to postmenopausal women optimal exercise intensities to lose body fat and reduce the risk of developing CVD.