We probably have heard it before but there is a new study that says three days of "gentle" exercise (such as cycling or jogging) a week will lower the risk of dying (from heart disease primarily) by 60% over a six year period. Since my knees are damaged from snow skiing, cycling is the only option.
http://www.dailyexpress.co.uk/posts/view/137593
http://www.dailyexpress.co.uk/posts/view/137593