Doctor John Ratey, author of A User's Guide to the Brain and co-author of Delivered from Distration has come out with a GREAT new book on how exercise affects your brain -  Spark: The Revolutionary New Science of Exercise and the Brain tells you in easy-to-read prose how exercise improves your focus (ADDers take note!), beats stress, improves your mood, improves your memory and more.  In fact, the right kinds of exercise actually GROWS more brain connections.  Not sure about keeping that New Year's resolution?  Read this book!