The list of things that can take a toll on your mind is nearly endless. Something as simple as fatigue or as complicated and detrimental as Alzheimer’s disease has an effect.

If you want to make your body stronger, you lift weights. If you want to make your mind stronger, it makes sense to challenge your brain with mental exercises. Studies have shown that brain training can help delay the symptoms of dementia, and the Alzheimer’s Association recommends keeping an active mind as a way to help slow down the disease.

Try these brain training exercises to help improve your mental fitness and stay sharp:

* Read a book – Books are a great way to pass the time and a perfect way to flex your brain power. It’s especially useful as an alternative to television, which studies have tied to an increased likelihood of dementia.

* Solve a puzzle – Work through the crossword in the paper, or find a Sudoku book and add up some mental effort. Try a variety of puzzles and word games to mix things up and stimulate different parts of your brain.

* Take a course – Completing a course requires many things that can benefit critical thinking and brain function. What’s even better is that many colleges offer free courses for older adults. Or, try the free or low-priced offerings of a massive open online course (also known as MOOCs). See a list of available topics at http://mooc.org.

* Exercise – Studies have shown a link between mental function and exercise. Start small with a walk or a session in your garden to help you stay in better mental and physical shape.

* Practice small movements – Take up a hobby that requires the use of your hands such as needlework, painting, playing cards or assembling jigsaw puzzles. The attention to detail these activities require will help you stay nimble and maintain focus.

* Play an online brain game – Several different companies offer brain games specifically designed to keep you sharp. These come in the forms of online portals or apps that you can download to your smartphone. Many of these sites require payment, but some of them feature free games as well, such as http://aarp.org.