5 stretches to test your flexibility. (It may help you live longer.)

Researchers followed them for more than a decade. They found that people with the stiffest joints — especially women — were substantially more likely to die prematurely than those with greater flexibility.

“We have very much undervalued flexibility,” said Claudio Gil S. Araujo, the study’s lead author and director of research and education at Clinimex, an exercise medicine clinic in Rio de Janeiro where the data was collected.

• Find a partner to provide gentle assistance, helping you reach each joint’s full range of motion.
• Try the stretches pictured in the five images in this article, starting with the picture of the wrist test at the top. Next test your knees, ankles, hips and shoulder. The order of testing doesn’t really matter.
• Stop when a move feels too uncomfortable.
• Score yourself from zero to four, based on how closely your own stretch matches the poses shown in each image. Two is average. A zero isn’t unusual, but scores below two suggest your joint is inflexible, Araujo said. Fours are rare, outside of gymnasts.

How to improve your flexibility

Tight joints frequently discourage people from being physically active. They can also affect everyday life. “It becomes hard just to lean over and tie your shoes if your back is very stiff,” Araujo said.

If your results seem low — or you suspect, even without checking, that your body is too stiff — it’s possible to improve your flexibility, although it requires diligence.

Araujo suggests regularly stretching and working various joints and muscles, even — or especially — while you’re at your desk.

• Cross one foot over the top of your opposite knee while seated, for instance, which focuses on your knee joint, and also roll your elevated ankle through its full range of motion. Continue for a minute or so.
• Reach behind your head with one arm as far as possible toward your opposite shoulder, as if trying to scratch an inaccessible itch. Hold for another minute.
• Reach straight toward the ceiling with your arm, stretching your shoulder and elbow.
• Get out of the chair, turn back toward it, and step onto the seat with one foot, which helps work your knees, lower back and ankle.
• Repeating these moves a few times throughout the day may help reduce stiffness.

Yoga, tai chi, swimming and even walking likewise increase flexibility in people of various ages, studies show. Visiting the gym might make us more supple, too, since strong, healthy muscles stabilize and protect joints. In a study published in June, researchers found that eight weeks of weight training improved people’s joint range of motion as much as eight weeks of regular, sustained stretching, while also amplifying their hip and lower-back strength.

But almost any regular activity should help to make and keep us relatively flexible, said David Behm, a professor at Memorial University of Newfoundland and co-author of the weight-training study. (He was not involved in the study of mortality.)

Flexibility influences life span, especially for women

To compare how flexibility scores related to life span, the researchers checked death records in Brazil for about 13 years after people first took the Flexitest at the clinic. They limited their search to deaths from natural causes, such as heart disease, but not accidents, because they wanted to see how flexibility had influenced people’s health and longevity but not their misfortunes.

“We weren’t sure what we’d find, since this wasn’t an issue that had been looked at before,” Araujo said. “But the correlations were clearly there.”

The links proved to be strongest among the women in the study. Those who’d scored lowest on the Flexitest were about five times more likely to die prematurely than women with the highest scores, the data showed, even after researchers controlled for age, body mass index and general health.

For men, the risk of premature death was about two times higher when their joints were tight than if they were more pliable.

This gender discrepancy could be explained, in part, by the wide gulf between men’s and women’s general flexibility, Araujo said. Overall, women were about 35 percent more flexible than men. So women with the lowest flexibility scores were greater outliers than men with low scores, possibly contributing to the women’s heightened risks of premature death.

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