Challenging your brain with new and unexpected experiences -- sometimes referred to as "neurobics" -- can help keep it stronger into old age.
"Breaking with routine, and using all your senses, is like having your brain cells lifting barbells," says Manning Rubin, co-author of the book "Keep Your Brain Alive".
* Make life your "gym." You don't need to use a computer or puzzle book or schedule a specific time to sharpen your brain. Instead, think of ways you can break your usual habits throughout the day.
* Close your eyes. Listen to sounds in the park, take a shower, navigate around your house or try to identify objects by touch without relying on sight.
* Use your nondominant hand. Eat, brush your teeth, dial a telephone number or write with the hand you don't normally use to give different parts of your brain a workout. Or try to button a shirt, tie a shoe or get dressed using just one hand.
* Vary your commute. Get off at an earlier bus stop or drive down different roads on regular errands or trips to and from work. New sights, sounds and smells will take your brain off auto-pilot.
* Mix things up. Have people sit at a different spot at the dinner table, trade chores with another family member or rearrange dishes in a cabinet so you'll have to think about where you're reaching.
* Try something new every day. This can be something small -- tasting a different food, say, or using chopsticks at dinner -- or bigger, such as picking up a new hobby or tackling a skill such as a foreign language.
* Combine your senses. Read a book while burning a scented candle, and pay attention to both. Or close your eyes and try to identify a food by smell alone.