If you’re an older adult, you’ve probably fallen into the trap that one doctor calls “the narrowing.”

“Most of my patients have no idea it’s happening. They think it’s just aging. It’s not,” Dr. Howard Luks, an orthopedic surgeon, wrote on X.

It’s simple: What you believe your body can or can’t do becomes true.

But the important thing to know, Luks stressed, is it’s not inevitable — and you have a lot more control than you think.

Luks sees it all the time, more than he sees injuries or surgeries.

“You used to carry four grocery bags. Now you take two. You used to sit on the floor with the grandkids. Now you sit on the couch,” he said.

“The narrowing is the slow shrinking of what your body allows you to do — or what you assume your body can or should be doing at your age.”

The problem, he said, is people experience some limitations and adjust to them, rather than try to push through or overcome them, assuming there’s nothing they can do about it.

“Your body quietly loses some capacity, your daily choices adjust to the loss, and within a few years, the smaller version is your new normal,” he said. “Patients tell me about the narrowing every single day. They just don’t use that word. They say, ‘I can’t do what I used to do.’ Or they say, ‘That’s just what happens at my age.’ And they say it as if it’s a law of physics.”

There are over 61 million people over the age of 65 in the US, and the number is expected to rise to 82 over the next few decades. In fact, the US population is older today than it has ever been.

With this change in demographics, we’re learning more about aging in America and attitudes are shifting.

Instead of seeing age-related decline as something inevitable, more doctors and other experts are emphasizing the amount of choice people have in the matter.

“Yes — some decline is real,” Luks said. “But the unavoidable decline is only a small fraction of what most people are actually losing. The rest — the bigger part, the part that turns a sixty-year-old into a frail seventy-year-old — is not aging. It is disuse.”

Stereotypes about age rarely originate in the person aging. It starts in the world, culturally, in songs or movies, in policy and laws, and at the doctor’s office.

Even at a young age, people get the message that aging means naturally losing function. And when they actually start aging, they might put in less effort to keep up daily tasks, seeing it as something naturally lost.

Luks urges people to see that decline is not something “scheduled” and should be questioned.

“Once the narrowing starts, it accelerates on its own. You stop lifting heavy things. Your muscles lose fast-twitch fibers. You get weaker. You lift even less. You lose more. The loss feels like aging. You accept it. The loop tightens.

But it’s not inevitable. A recent Penn State College of Medicine found that engaging in as little as four minutes of strenght-training exercise can quadruple fitness in older adults.

Having the right attitude helps: A new study from Yale showed that people can actually improve their physical and cognitive health after age 65 — especially if they have a positive view of aging.

“You still have agency,” Luks writes. “I am not a one-off. I am a 63-year-old who decided not to let my life narrow, and who did the specific work to back up the decision, for long enough that the work is now visible.”

Ohio State University recommends keeping up movement, like walking, eating better, assessing medications, getting enough sleep, and connecting more with others, in order to combat frailty.

“You can do this too. At any age, start where you are… I saw this freight train coming nearly 2 decades ago… I was lucky to do so.”