The Chair as a Measuring Instrument

It starts with a chair, more precisely, an ordinary kitchen chair without armrests. Anyone who rises from it and sits back down five times in a row as quickly as possible, with their arms folded across their chest, is completing one of the most informative tests in geriatric medicine. In clinics, it is called the Chair-Rise Test, and it measures something we constantly need in everyday life: the strength of the thigh and gluteal muscles.

These are precisely the muscles that deteriorate first and fastest with age. They carry us up the stairs, lift us out of an armchair, and catch us when we stumble.

The time is measured from the first time you stand up until the fifth time you sit down. Anyone who takes longer than 15 seconds is considered to have an abnormal result. ^[1]

The folded arms are not merely a formality. Anyone who supports themselves with their hands shifts part of the work to their arms, meaning the test no longer measures leg strength. If standing up is only possible with the help of the hands, that is already the result, even without looking at the clock.

Why Muscle Strength Matters More Than Muscle Mass

In 2019, a European working group revised the definition of sarcopenia and made muscle strength the most important criterion, ahead of muscle mass. ^[1] The reason: Muscle strength predicts more reliably than muscle mass whether a person will fall, need hospitalization, or lose their independence.

An international panel of experts confirmed and expanded on this view in 2024. Accordingly, muscle mass and muscle strength describe the disease itself. How well someone walks, stands up, or climbs stairs, on the other hand, is a consequence of it. ^[2]

A 2025 German review quantifies what this can mean: In people with sarcopenia, mortality is approximately doubled, and they need to be hospitalized significantly more often. ^[3]

For self-testing, the shift toward strength is good news. Muscle mass cannot be measured at home, but muscle strength and mobility can.

Four Meters at a Normal Pace

The second test requires a tape measure and a stopwatch. Measure out four meters on the floor, with two meters of approach beforehand so that your pace is already steady when you start. Then walk the distance at your usual pace, not faster than normal, and you may use a walking aid.

Measure the time needed to cover the four meters. Anyone who takes more than five seconds is walking slower than 0.8 meters per second, and this value indicates advanced sarcopenia. ^[1]

For comparison, pedestrian traffic lights are designed for a faster walking pace. Anyone walking below 0.8 meters per second may no longer be able to cross a wide road during the green phase.

Calf Circumference as a Substitute for Muscle Mass

How much muscle mass someone has can be determined in a clinic using a specialized X-ray measurement. At home, there is a surprisingly useful substitute: a tape measure around the calf.

Measure while seated, with the knee and ankle each bent at approximately a right angle, at the thickest part of the calf, without tightening the tape. A circumference below 34 centimeters in men and below 33 centimeters in women is considered an indication of low muscle mass. ^[1]

However, this measurement is not useful in cases of severe overweight or fluid retention in the legs, because fat or fluid, rather than muscle, determines the circumference.

Grip Strength

Grip strength is the measurement most commonly used in medicine, and it is the only one of the four tests that requires a device. Many medical practices, physiotherapy clinics, and sports medicine facilities have a hand dynamometer.

Measure while seated, with the elbow bent, three times per hand. The best attempt is recorded. Grip strength is considered weak below 27 kilograms in men and below 16 kilograms in women. ^[1]

If you do not have a device available, you do not need to wait to take this test. For an initial assessment of whether there is a problem at all, the other three tests are sufficient, especially standing up from a chair.

What the Results Mean

A single abnormal result is not yet a diagnosis. Anyone who falls below the cutoff in two or more tests should have this medically evaluated.

Declining strength is not always due to age. An underactive thyroid, anemia, vitamin D deficiency, an undiagnosed inflammation, or medication side effects can produce the same results, and they can be treated.

The tests are also useful for making progress visible. Muscle strength and walking speed respond to training faster than muscle mass does. ^[4] Anyone who records their values today and repeats the tests in three months can see whether the training is working.