It’s easy for us to sit down in front of the TV and surf mindlessly through channels until we’re ready for bed. We might make sure to watch Jeopardy! and Wheel of Fortune and feel proud when we get the answer ahead of the contestant, but what else can we do to keep our brains sharp?

Studies have shown that mental exercises are a great way to sustain and build our mental acuity as we get older, and there are a lot of online resources you can use to exercise your mind. Here are just a few sites that you can visit regularly and stimulate your brain!

1. AARP’s Brain Games:
If you’re a member of the AARP, you have free access to these brain games, which will stimulate, strengthen, and sharpen your mental skills.

2. Easter Seals Train Your Brain:
Another great organization, Easter Seals provides some great tools and puzzles that will challenge you and motivate you to keep trying more every day. The first one is free, but expect to pay a fee if you want to continue. Reviews we’ve seen indicate that it’s worth it, though!

3. Web Sudoku:
If math is your thing, how about an unlimited number of Sudoku puzzles? No more having to go out and buy more puzzle books when you have access to thousands of puzzles randomly generated for your needs.

4. Lumosity:
Although this site also offers games and puzzles under a subscription fee, the high quality of the puzzles and games you’ll find will be worth it. Lumosity measures the metrics of your activity as well, charting your progress and growth across their site.

5. Sporcle:
A giant free site filled with trivia of all types, from geography and history to pop culture and celebrities, Sporcle has plenty of diverse types of quizzes that test a broad range of knowledge and might even teach you some current trivia that will keep you in the loop with grandkids.

So next time you’re thinking about flipping channels, maybe pull up the computer or iPad and give your brain a workout! You’ll feel better, stay sharp, and be happy you did it!