45 or so minutes of moderate exercise each day or most days of the week. After a certain point- about 20 minutes- the body starts burning more fat than before that, so walking at a brisk pace for that length of time or cycling or swimming, the idea is to keep your heart rate up. Check with your doctor to make sure it is safe for you to do so much exercising. You burn more calories the harder you work, but don't overdo or you'll hurt yourself and not want to continue. Do something or several things that you enjoy doing.
at 12:10 PM on Feb. 12, 2009