While staying physically fit is important, so too is preserving mental fitness. Two new books explore ways to keep your mind as healthy as your body. In Brainfit: 10 Minutes a Day for a Sharper Mind and Memory, Corinne L. Gediman prescribes daily mental exercises designed to slow age-related mental decline. Good brain exercises challenge the brain to think in new ways and may also include a component of physical exercise and social interaction. The majority of Brainfit is dedicated to dozens of fun, easy memory exercises. For example, to remember all the items on a shopping list, visualize each item, then pair it with the next item on your list. If you need to pick up sand and candles at the hardware store, Gediman advises visualizing a sandcastle at dusk with candles glowing in the windows. Follow her program, and you will soon be bowing to the goddess of memory, Mnemosyne (try remembering that name).