You can tell you're getting older when simply getting out of a chair starts to feel like a workout. 

It happens to all of us, usually far sooner than we expect. Suddenly, every time you get in or out of a chair, there's a veritable chorus of sounds from both your joints and your own mouth to mark the occasion. But it turns out that this simple movement we make every single day is also a revealing indicator of our overall health. In fact, doctors use a simple 30-second sit-to-stand test to assess how well our bodies are aging, and the results can reveal a surprising amount about our physical health.

We're bombarded with health assessments nowadays (many of them of dubious credentials), from at-home blood testing kits to all those supposed "cortisol face" tests you can find on TikTok to, of course, about a million "psychological" assessments.

But doctors have known about one of the simplest tests of well-being for ages: the 30-second sit-to-stand test, used in doctors' offices and community clinics, especially to evaluate the health of senior citizens. All you do is sit in a chair and get back up out of it, over and over again for 30 seconds. That's it! But what it reveals is extensive.

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Doctors use the test to evaluate everything from cardiovascular health to surgical risks. "It's a really helpful test because it tells us so much about how well people are functioning," geriatrician Jugdeep Dhesi recently told the BBC. "It tells us about their strength, their balance and their flexibility."

And it doesn't stop there. The test can also help doctors identify people who may be at greater risk of falls and certain health complications. Research has even linked poorer physical performance on similar tests to an increased risk of mortality. Yikes. But the fact that something as simple as standing up from a chair can offer clues about long-term health is pretty incredible, right?

Many people can try this test at home using a sturdy, straight-backed chair without arms and a stopwatch, like the one on your phone. Make sure the chair won't slide, and if you have balance problems, significant joint pain, or difficulty standing safely, talk to a healthcare professional before attempting it. Simply sit in the chair, cross your arms over your chest with each hand on your shoulder, and start your stopwatch. Then rise from the chair and sit back down again and again, noting how many times you can complete it in 30 seconds.

A poor score on the test can alert medical providers to risks associated with surgery or cancer treatment and may indicate that something is wrong with the lungs or cardiovascular system. So if you struggle with the test, it might be worth booking a doctor's appointment.

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The Centers for Disease Control provides age-based reference scores for the 30-second sit-to-stand test. According to its guidelines, men ages 60 to 64 who complete fewer than 14 repetitions and women who complete fewer than 12 fall below the average range. For adults ages 90 to 94, those numbers are fewer than 7 for men and fewer than 4 for women.

Because the test is usually intended for the elderly, standards for those under 60 haven't been established. But a 2022 study published in the International Journal of Sports Physical Therapy, which applied the test to men and women aged 19-35, found that the average number completed in 30 seconds was 33.

Another study in Switzerland looked at a similar sit-to-stand test in adults aged 20 to 24, but participants performed it for a full 60 seconds instead of 30. Researchers reported averages of approximately 50 repetitions for men and 47 for women. Some more physically fit people were able to do as many as 72 repetitions in a minute, however.

It's important to note, of course, that everyone's capabilities differ, and it's vital to consult your doctor before pushing yourself with any physical activity. But scientists have found that for younger people, the sit-to-stand test can be a useful measure of overall physical fitness, particularly for lower-body muscle strength and endurance.

So if you complete the test with ease and flying colors, take heart that your lower-body strength and endurance may be in pretty good shape. And if you struggle, don't panic. Your results could be a useful starting point for talking with your doctor about your physical health, all from simply sitting down and standing back up from a chair.

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John Sundholm is a writer, editor, and video personality with 20 years of experience in media and entertainment. He covers culture, mental health, and human interest topics.