Keep in mind that I said "challenge your muscles," not just simply use them.
You use your leg muscles all the time when you walk. Your quadriceps, hamstrings, calves, and butt muscles are always activated when you're walking. But people still lose the ability to walk without assistance as they get older.
People use their arm muscles all the time when they pick up something. They stimulate their biceps, triceps, forearm muscles, and shoulders whenever they push or pull anything. If you go shopping and use a shopping cart, you're not just using your arms, but also your chest muscles. Yet, you could still get weak in these areas as you get older -- so much so that pushing a walker would be a problem.
You are always using your muscles. But are you CHALLENGING your muscles? When you challenge your muscles, you are not just keeping them active, but you are also keeping them from deteriorating.
Think about it like this. I teach dance fitness classes twice a week and I have a following of over 60 people per class. Let's say that I've decided to stick with the same exercise routines and the same music for every class. A month goes by and I'm still playing the same music and using the same exercise moves. Three months go by and I'm still sticking with the same moves. It's nauseating just thinking about this!
How many people do you think I'll still have coming to my classes? Right, not many! People would get bored and start dropping out. They won't refer anymore friends to me. Eventually, I may have a class of five people, all of which are new. They'll keep coming until they get bored of the routines and music and they'll leave. Then I won't have a class anymore.
Same thing with your muscles. You may keep them activated by continuing your daily routines, but eventually the body won't see anymore use of your strength. So as you get older, your muscles would decrease in size and your strength would slowly go away. Eventually, you'll be the patient who calls 911 because you fell down and can't get up. You're not strong enough to get up! You know how toddlers could fall and jump back up? Well, you'll be weaker than them!
Even if you were to exercise regularly, if your exercises aren't challenging your body, then you'll still get weak and broken down.
Yes, you walk everyday. So what? You'll still lose your leg strength if you only walk, especially if you walk the same distance. You'll find that walking is getting harder and harder. You'll find that you're getting out of breath more easily. Eventually, you'll stop walking.
Are you an avid jogger? If your exercise is at the same intensity, then eventually you'll break down.
Even if you lift weights, if you're lifting incredibly light weight and don't challenge yourself to lift more, then your muscles will break down.
The same applies to your brain. I don't care how much you read, if you're not challenging your mind, then you, too, will suffer from deteriorating diseases of the brain.
No, you don't have to learn a new language or become a math whiz. You just need to seek new things in life. Start writing books, take new classes, learn a new skill. Do something different for your brain. If all you do is read the newspaper and watch the news, then your brain will eventually break down.
If you want to live a healthy, vibrant life well into old age, continue to challenge your mind and body.
Businesses understand that if they don't continue to change how they do things, they won't grow and would eventually go out of business. Recently, I've noticed that the Federal Postal Services are putting out these catchy commercials advertising new services that they provide. For the longest time, you just simply went to the post office to mail out a letter -- and MAYBE send out a package. Now that UPS and FedEx are around, we don't really need the post office to send out packages. And now that most businesses offer their customers to pay bills online or have their money debited from their bank account, there's really no need to use the post office to send checks or money orders.
Heck, I used to buy lots of stamps because I was always sending out mail. Not anymore! If I need a stamp, I'll just pay for one when I get to the post office. I don't need a booklet of stamps anymore.
As time changes, using the postal service won't be needed anymore. So if the U.S. postal service wants to stay in business forever, they would need to change how they do things and offer more to their customers.
Any business that fails to change with the times and meet new challenges won't grow and will go out of business. The same thing with your body. If you continue doing the same thing as you've always done, your body will eventually go out of business.
Start a new business. Offer more services in the business you have. If you're an exercise instructor, change up the routines often. Change the music often! If you lift weights, then lift more weights and lift them differently. If you have a college degree, get another one. If you have a certificate in something, get another one. Travel more often. Learn new skills. Learn new languages. Seek different things in life. Do the usual things differently. Always seek to be better, to do better, and to live better. Once you become complacent, that's when you stop changing and that's when you start deteriorating.