1. How do I keep my brain young?
2. How do I keep my brain agile?

Puzzle fans may be discouraged to learn that one of the best ways to keep your brain young is physical exercise. When our bodies are in motion, the individual cells tell the brain to grow and to repair itself. One hour of physical activity per day can keep your brain in good repair for a century. Keep your body moving under your own power (walking, running, cycling, swimming, etc.) to keep your mind sharp. See Younger Next Year: Live Strong, Fit, and Sexy - Until You're 80 and Beyond by Chris Crowley and Henry S. Lodge (Workman Publishing Company, 2007).

The other great way to help your brain stay young is emotional. Humans are social animals. Studies continue to show that our health improves when we have positive interaction with others. This is even more important for brain health. Have daily contact with friends and family. Even having pets can help satisfy the need we have for social interaction. The Web can help you meet kindred souls, but don’t rely on virtual friendships. Meet with friends face to face. If you have trouble making friends in positive relationships, try reading and applying How to Win Friends and Influence People by Dale Carnegie (Simon & Schuster, 2009).

Get 7 to 8 hours sleep every night. Sleep not only allows your body to rebuild, it provides a playground for your mind. No one is truly healthy without adequate dreaming time. If you have trouble sleeping, consider the tips at www.helpguide.org/life/sleep_tips.htm.

Reduce stress in your life. It causes wear and tear on your body and can keep you awake. Much of the stress in modern society is probably unavoidable, but how we react to that stress is under our control. Don't let troubles get you down. Read How to Stop Worrying and Start Living by Dale Carnegie (Gallery, 2004) and The Magic of Thinking Big by David Schwartz (Fireside, 1987). They can help you cope with stress in your life.

Eating right is good for your brain. We all know what we should be eating, but we often stray. We need the right building blocks so that our brains can do the building. See www.elder.com Brain Foods and Supplements for some suggestions on the best brain foods.

Being lean is good for your physical health, but diets usually fail in the long run. Focus on portion control and on avoiding snacks. Combined with exercise and choosing sensible foods, you should maintain a healthy weight.

At last, we get to the puzzles. Our brains need stimulation and activity to stay sharp. Puzzles are a fun way to keep our brain cells working, but there are other ways. Learning, performing, and even composing music are other great ways to work the brain. Square dancing is popular for its exercise as well as its mental workout. Find activities that maintain your interest and stimulate your brain.

Solving problems is easier for the trained mind. We can learn how to think. Each technique we learn becomes a new tool in our tool kit. The agile mind has many tools and practices using them. Brain Trainer – Puzzles to Keep Your Mind Young and Agile, by William Armstrong (William Armstrong, 2011) teaches us numerous techniques for solving puzzles and, by extension, for tackling many other problems. Even teens preparing for the SAT can benefit from improving their "puzzle IQ." The SAT was redesigned in 2005. The reasoning and math sections now favor students who are good at puzzles over students who know their school subjects by rote.

A memory is like a message written on the side of a phone book. A tiny bit of each message is written on the edge of hundreds of pages. When we don’t access that memory, it is like pages being torn out of the book. Even with many pages removed, we can still read the message, but it may be harder to recall. Memory can be strengthened by repetition. Use it or lose it. Periodic recall of the things we wish to remember prevents the "pages" from being torn out.

An agile mind is creative. It synthesizes ideas in fresh, new ways. It thinks in stories. It dreams and designs valuable creations. The right hemisphere of the brain seems to be seat of these creative processes. Like other mental processes, creativity can be strengthened with appropriate exercises. See A Whole New Mind by Daniel Pink (Riverhead, 2005) for a detailed commentary on how and why we need to build our right-brain skills.

How fast we can think is dependent on practice, confidence, brain health, and fatigue. Big winners on Jeopardy! practice endlessly. Watson, the computer Jeopardy! champion, won't buzz in unless it has enough confidence that its answer is correct. Confidence in human brains is built through reinforcement (practice). Mental speed can be cultivated, but it is rooted in training and recall skills.