When you reach middle-age-around 53 years or so-there are three simple tests you can perform that will tell you if you are going to live to a ripe old age.
Standing on one leg with your eyes closed for 10 seconds or longer, having a firm grip and standing up and sitting back down in a chair as many times as you can in a minute are all tell-tale signs of longevity.
Perform well in all three tests when you are 53 or so and you should be healthy and vibrant 13 years later, when you are 66.
Researchers from University College London reckon that a 53-year-old who can complete the tests successfully is up to five times more likely to be alive and well 13 years later than someone who couldn't complete the tests or performed them poorly.
They tested 1,355 men and 1,411 women in 1999-when they were 53 years of age-and then checked to see who was alive and well 13 years later in 2012. There were far higher death rates among those who could not complete the tasks.
Tests included the chair test (standing up and sitting down again in a chair 39 times in a minute, and 36 times for a woman), the balance test (standing on one leg for 10 seconds or longer with eyes closed), and the grip test (an ability to apply pressure of up to 54.5kg).
(Source: British Medical Journal, 2014; 348: g2219)