One-leg stance test

The one-leg stance test asks how long you can balance on one foot. In a Brazilian clinic cohort, the one in five middle-aged and older adults who could not hold it for 10 seconds were about 84% more likely to die over the next seven years. A larger Japanese study of over-65s found that the weaker leg carries the signal. It is a warning light, not a lever: nobody has shown that training to pass it extends life.

Time both legs once a year and read the worse one. Under 10 seconds on either side is a reason to start balance training and retest, not a diagnosis.

How to do it

Stand barefoot. Rest the top of your free foot against the back of your standing leg's calf, keep your arms by your sides, and fix your eyes on a point at eye level about 2 metres away. Time how long you can hold without touching anything, up to 30 seconds. Ten seconds was the Brazilian study's pass mark; it allowed up to three attempts and counted a pass on either foot.^[1]

That either-foot rule throws information away. Time each leg separately and note the worse one, because that is the leg the Japanese study found mattered.^[2] Stand next to a counter or wall you can grab, and stop if you start to fall.

What the Brazilian study found

The study followed 1,702 adults aged 51 to 75, about two-thirds of them men, for a median of 7 years. About one in five could not stand on one leg for 10 seconds, and failure became steeply more common with age.

Of those who failed, 17.5% died during follow-up, against 4.6% of those who passed. Much of that raw gap is age: after allowing for age, sex, body mass index and conditions such as diabetes, high blood pressure and coronary heart disease, the people who failed were about 84% more likely to die (hazard ratio 1.84; the plausible range ran from 1.23 to 2.78).^[3]

People who failed were also less healthy to begin with. Diabetes was about three times as common among them, 38% against 13%.

Why to hold the number loosely

The participants came from a single exercise-medicine referral clinic in Rio de Janeiro. Most were white and from higher socioeconomic groups, about a third had coronary heart disease and about half had high blood pressure, so they were not a typical community sample.

The study also could not account for several things that affect balance and survival: recent falls, physical activity and sport, diet, smoking, and medications that impair balance. The same research group produced the sitting-rising and flexibility studies, so those signals are not independent confirmation of each other.

The weaker leg matters

The Japanese study timed both legs in 3,278 adults aged 65 and over who were living independently in two municipalities, and followed them for a median of about 7 years. The outcome was harder than death alone: loss of independence, meaning needing complete help with basic daily activities such as washing and dressing, or death. It happened to 452 people, about one in seven.^[4]

Compared with people who could hold their weaker leg for 30 seconds or more:

Under 10 seconds went with about twice the risk (hazard ratio 2.17; the plausible range was 1.67 to 2.84).
10 to 20 seconds went with about 1.5 times the risk.
20 to 30 seconds showed no clear difference.

The pattern held even in people whose better leg was normal. This is the first large replication by an independent group, in a different country and a community sample, which makes the test more trustworthy than the Brazilian study alone could. It is still observational.

What it can't tell you

Both studies show that people who fail the test do worse on average. Neither shows that training until you pass changes your outcome; neither was designed to test that.

Tests like this sort large groups far better than they predict what happens to one person, so a pass is not reassurance and a fail is not a diagnosis. Read it as a prompt to train balance and to retest in a year.

What to do

Test once a year: both legs, barefoot, eyes open, up to 30 seconds each, next to something solid.
Read the worse leg. Under 10 seconds on either side is the clearest warning; 10 to 20 seconds is a milder one.
Respond by training balance directly, alongside strength and power work. Drills, progressions and targets are in Training mobility and balance.
For the other at-home checks, such as getting up off the floor (Sitting-rising test) and walking speed, and for how to respond to a fall, see Mobility and balance.