Everyday Ways to Stay Sharp

45. Bear some weight. Adding a little strength training to your daily walks can help protect brain cells from damage done by free radicals—and encourage new brain-cell growth. So strap some weights on your ankles or wrists as you walk, or practice gentle yoga.

46. Let yourself sleep in. Research shows that when you're chronically sleep-deprived, your body doesn't have the time to build proteins and other brain- boosting components. So instead of waking yourself early, sleep until you wake naturally.

47. Take an afternoon catnap. Most of sleep's boost to concentration and memory happens in the first stage, so even a snooze as short at 30 minutes can benefit your brain.

48. Switch hands. It may be uncomfortable, but writing with your nondominant hand or operating a computer mouse with that hand can activate parts of the brain that aren't easily triggered otherwise. Anything that requires the brain to pay close attention to a formerly automatic behavior will stimulate brain-cell growth.

49. Shake your body. Gentle bouncing of your knees and shaking out of your limbs reduces the brain-sapping stress hormone cortisol, research shows. It also triggers relaxation and alertness that keeps your brain sharp. Do it for a few minutes in the morning and at night.

50. Tour your neighborhood. If your neighborhood is growing, check it out. The exploration will change your mental map of the neighborhood. Along with learning new and better routes to your favorite stores or restaurants, you'll forge new neural pathways in your brain.