A service dog puts her many impressive skills on display in this adorable video.

One of the biggest battles of healthy aging is staying mentally sharp. Having a healthy brain is important for mental and physical longevity.

Data from the Centers for Disease Control and Prevention (CDC) reports that 6.7 million older adults in the United States have Alzheimer’s disease, the most common type of dementia. The CDC notes that by 2060, that number will double.

However, being proactive about brain health can help keep aging brains thriving. In an online forum of Boomers and older Gen Xers, they opened up on how they keep their brains sharp and memory strong. These are 40 surprising (and simple) ways they've maintained healthy brains as they've aged.

  Aging Old Man GIF by A&E  Giphy  

"I take on-line college courses. Pick one out that piques my interest and sign up. The advantage at my age is I can study whatever I want, I'm not really concerned with advancing my career. Ancient Mediterranean History? Sure why not? History of Beer? Why not? Psychology of Evil? Sounds interesting. All on-line, all cheap. Keeps my brain active." - mike11172

"I'm way into fitness and still work out with weights. Also walk a lot and do fun things outdoors. I make sure that I get outside at least an hour every day. I'm careful to eat good foods that meet nutritional requirements, especially since I work out. I drink plenty of fresh filtered water. Taking care of your health in these three ways really makes a difference in one's mental sharpness and attitude. I belong to a religion that encourages me to treat others kindly and to be thankful for the life I have. Participate in activities that involve helping others. That really makes anybody feel good, have a purpose, and be glad they have the means to give of themselves. My husband and I make a point to always treat each other like we're newlyweds. Keeping the stress in your home to a minimum improves your mental state. In my down time, I've gotten into paper art. It's fun and an easy way for anyone to stay creative. I make cute things and greeting cards for others." - Bebe_Bleau

  Learn The More You Know GIF by @InvestInAccess  Giphy  

"I write novels and memoir essays. The novels require a lot of research about settings and history. Unexpectedly, even the memoirs require research, because I took for granted behaviors and ideas that need to be explained for modern readers since nobody takes them for granted anymore. I volunteer for a local organization that helps provide food and medicine to households who have run out of money before the next paycheck. I work with recent immigrants who speak little English and am constantly learning new things about what it's like to struggle for survival in lives of utter poverty." - Building_a_life

"Just use it. The brain works a lot like muscles in the sense that it will degrade quickly if you don't use it but can maintain its abilities for a long ass time if you do use it. I've met so many older people who basically just stop doing anything that requires a lot of thought when they get older because thinking is a lot of work. And you can definitely tell that kind of person when interacting with them. Conversations with them feel more like talking with a bunch of pre-recorded responses. Just do stuff that requires a lot of thought. Learn new skills. Read about complex, interesting ideas. Do puzzles. Play chess." - Yak-5000

"Started flying a small airplane a few years ago at 64. Mentally challenging." - slick62

  New York Times Running GIF by PERFECTL00P  Giphy  

"All the many word puzzles: Wordle, Quordle, Octordle, Connections, Squaredl, Blossom, etc. Crosswords, jigsaw puzzles, hour + walks per day. Writing, reading, cooking. Day trips and quick trips of 1-3 nights. Working really got in my way!" - Conscious-Reserve-48

"Counseling. It is important to keep processing your feelings, otherwise they pile up." - arkofjoy

"I quit smoking and started juggling. I'm no performer, but it keeps the nervous system active and it's fun for the whole family. Learning new tricks that are counterintuitive is the hardest, especially with new devices. I mostly stick to 3 balls, as I prefer to get good with simple things." - Tempus_Fuggit

"I'm fixing up an old sailboat when I'm not doing house maintenance /upgrades." - darkcave-dweller

  Nick Kroll Fx GIF by Adults  Giphy  

"I have in-depth conversations with my GenZ kids. No restrictions on topics. They are phenomenally smart, well-informed, and engaged." - CommissarCiaphisCain

"Crossword puzzles. More importantly I work with teens who teach me the latest jargon among other things. I adore them all." - Kissoflife1

"I've spent most of my life living in foreign countries and really don't know any other life. My budget in old age allows me to annually travel solo to third world countries. I'm keeping my mind active by always trying to figure things out like communicating in some foreign language, organizing my own hotel reservations, traveling arrangements etc. Things frequently get off the rails, so I have lots of practice figuring out the answer to the questions like, what the heck should I do now?" - nonsense39

  spanish gif Giphy  

"I learned to play a musical instrument and I’m taking Spanish lessons. These activities really challenge the brain." - ClawhammerJo

"I consume very little mainstream news. The more mainstream news you watch, the less you understand about the world--it's not meant to inform, it's meant to divide us and manipulate our prejudices. Finally, I've adopted the idea that pessimists are pessimistic because they imagine they can predict the future. I know and accept that I can't predict the future, so I'm optimistic. The possibilities are, as they've always been, infinite. I don't dwell on the past, and I don't worry about the future." - crackeddryice

  Country Music Old Town Road GIF by Lil Nas X  Giphy  

"Line dancing. It uses the brain and the body, and in my area I’ve found I can dance several times a week." - littleoldlady71

"I read a lot of books. I listen to a lot of music. I hike as much as I can. I meditate daily. All seem to be important for my brain." - WingZombie

"A good brain takes regular practice. Think like a young person by talking to young people…asking them about their thoughts and ideas…they aren’t interested in my opinions much. Read about technological advances, social studies, philosophy and art. Learn and practice languages. And ride a motorcycle on and off road. My wife and I go somewhere or do something new once a week. I like getting strangers to laugh. I also smile and share joy wherever possible." - gorongo

"My Amazon deliveries are made to a set of lockers onsite. I will never walk up to the lockers and THEN pull out my phone to look for the code. I will look at the message with the code and force myself to remember it before I ever enter the building so I can just walk up to the lockers, enter my code and get my stuff without anyone having to wait on me. I find that my brain will spontaneously make all sorts of associations to the numbers that help me remember them. Whether this helps in the long run, who knows? I just know it kind of makes those trips to the locker like a game for me." - chonnes