Mobility tests offer clues, not predictions, on healthy ageing: experts

Your doctor asks you to stand up from a chair as many times as you can in thirty seconds. Or perhaps to lower yourself to the floor cross-legged, then rise again without using your hands. These tests have become fixtures in aging medicine, circulated on social media as windows into how well you're aging, how much longer you might have. But experts are pushing back against that narrative. The tests do something useful—they reveal where your body is weakening. They do not, however, tell you when you will die.

Strength and mobility assessments can measure real things: your stamina, your capacity to resist falls, your overall physical resilience. For doctors, they serve as diagnostic tools. A person who struggles to rise from a chair might have knee pain, weak quadriceps, or cardiovascular strain. A person who wobbles during a balance test might have inner ear problems or neurological changes. The tests are designed to narrow down the question, not answer it. "A poor or declining result is a reason for a health professional to investigate why function is changing, rather than gauging how long someone will live," according to Auriel Willette, a researcher at Rutgers University who studies brain aging.

The most common test in American clinics is called Timed Up and Go. A patient sits in a chair, stands, walks three meters, and returns to the seat. In those few seconds, a doctor can assess balance, mobility, and lower body strength all at once. It's efficient and revealing. Another test, popularized recently on social media, is more elaborate: you move from standing to sitting cross-legged on the ground, then back to standing. The scoring is precise—five points for getting down, five for getting up, with deductions for using your hands or showing unsteadiness. A perfect score is ten. Zero means you cannot do it without help.

The sit-to-stand test has generated particular interest because of research from Brazil. In studies published in 2020 and 2025, researchers found that middle-aged people who scored higher on the test were less likely to die within roughly a decade. The finding is intriguing. It is also limited. American doctors have not widely adopted this particular test with older adults, and the results come from a specific population studied in a specific way. What holds true for middle-aged Brazilians may not hold true for seventy-year-old Americans, or for people with different medical histories, different activity levels, different genetic backgrounds.

This is where the caution matters most. Experts emphasize that the validity of any test depends entirely on the population in which it was studied and verified. If a test has been shown to predict outcomes for one age group, the performance standards do not automatically transfer to another. A score that signals risk for a sixty-year-old may mean something entirely different for an eighty-year-old. A test validated in one country may not apply in another. The human body ages differently depending on genetics, environment, access to healthcare, and countless other variables.

Dr. George Hennawi, who treats older adults at MedStar Health in Baltimore, explains that all these tests share a common purpose: they are meant to pinpoint specific weaknesses and trace them back to their root cause. Is the problem in the knees? The reflexes? The sense of balance? The heart's ability to pump blood efficiently? Each test can help answer a different piece of that puzzle. But none of them is a crystal ball. They are tools for investigation, not prophecy. The value lies not in the score itself, but in what the score prompts a doctor to do next—to ask why, to dig deeper, to address the underlying problem before it worsens.