Does your balance on one leg say something about your life expectancy?
In people between the ages of 65 and 80, your balance on one leg does say something about your health risk, but it is a signal, not a prediction: a poor score is a reason to work on strength and balance, not a reason to worry without doing so.
How long you can stand on one leg does say something about your health and future, but it is not a simple yes or no: the difference lies in who you are, how old you are, and which leg is being measured. In community-dwelling people aged 65 and older, the weaker leg turns out to be the most informative measure. Those who can stand on that leg for fewer than 10 seconds are more than twice as likely to lose their independence or die in the following years, compared with those who manage 30 seconds or longer. Those who score between 10 and 20 seconds also face an elevated risk, though a smaller one. This association held up after adjustment for other health factors.
A striking finding: measuring only your best leg is not enough. Someone who scores well on their stronger leg but poorly on their weaker leg still faces an elevated risk. Measuring only the best leg therefore causes you to miss part of the picture.
For older people with cardiovascular problems, an even sharper threshold applies: those who can stand for fewer than 3 seconds have almost 70% higher odds of dying. In that group, the balance test proved even more informative than handgrip strength for detecting physical decline.
The relationship is not universal, however. In 80- and 85-year-olds drawn from the general population, researchers found no independent association between single-leg stance and mortality. At those ages, walking speed, step frequency, and muscle strength proved to be better predictors. This suggests the test is most useful roughly between the ages of 65 and 80, and less discriminating in the very oldest.
Practically speaking: if you measure your single-leg stance at home with your eyes open, that is a reasonably reliable measurement. The eyes-closed version is too unreliable at home to draw meaningful conclusions from. A poor score is not a verdict, but it is a reason to work on strength and balance, and possibly to discuss it with your GP or physiotherapist.
This answer is based on multiple studies in older adults, most of which followed participants for several years without assigning or changing anything in their behaviour. This means that associations were found, but cause and effect have not been proven. The strongest findings come from research in community-dwelling people aged 65 and over. In the very oldest (80+), the studies partly contradict one another: two separate studies in people in their eighties and mid-eighties found no independent association with mortality. The researchers who examined the weaker leg described that as an addition to existing research that had looked only at the best leg.
How many extra years of life does regular walking provide?
Regular walking is associated with two to six extra years of life, with the greatest gain for people who currently barely move. Even half an hour per day makes a measurable difference.
How much longer do you live from fifteen minutes of exercise a day?
Just fifteen minutes of moderate exercise a day is associated with an average of 3 years of longer life expectancy. Doing more yields more benefit, but even this minimum makes a measurable difference.