If you’re over 40 and you can sit on the floor, reach for your toes and get your fingers past them, some new research suggests this is a sign that your artery and veins are flexible.

It’s an unusual suggestion – how flexible you are on the outside as a way to tell how flexible you are on the inside, but this is precisely what the team of Japanese researchers uncovered.

Arteries are known to naturally stiffen as we age, long recognized as a forerunner of dangerous cardiovascular disease.

“Our findings have potentially important clinical implications because trunk flexibility can be easily evaluated,” points out study co-author Kenta Yamamoto of the University of North Texas and the National Institute of Health and Nutrition in Japan. “This simple test might help to prevent age-related arterial stiffening.”

In the study, 526 adults, nonsmokers who were not considered obese, between the ages of 20 to 83 took part in the sit-and-reach test described above. The team measured how far each of the subjects could reach, classifying them as either poor or high flexibility.

Blood pressure readings, as well as other measurements of cardiovascular health were taken, and participants were tested for cardiorespiratory fitness, muscle strength and endurance. The participants were divided, by age, into young, middle and older groups.

The team found that trunk flexibility did appear to be a good predictor of artery stiffness for the middle aged and older group, not so for the young. The systolic blood pressure (top number, when heart is beating) was higher in poor flexibility subjects.

It’s not clear if there is a direct, cause-and-effect relationship between being more flexible and having less stiffness in the arteries. The researchers do cite another recent study that found regular stretching exercises in middle age and older adulthood significantly improved the flexibility of the carotids, major arteries found in the neck.

Healthy blood vessels are supposed to be elastic, flexible, therefore helping to moderate blood pressure. Earlier research has shown that being physically fit as you get older can hold off age-related arterial stiffness, though how this works is still a mystery.

One theory to explain why flexibility would be linked to the stiffness of the arteries is that stretching exercises may set off physical reactions that slow down the natural stiffening of the arteries so typical of aging.

“Together with our results, these findings suggest a possibility that improving flexibility induced by the stretching exercise may be capable of modifying age-related arterial stiffening in middle-aged and older adults,” says Dr. Yamamoto. “We believe that flexibility exercise, such as stretching, yoga and Pilates, should be integrated as a new recommendation into the known cardiovascular benefits of regular exercise.”

The findings appear in the October issue of the American Journal of Physiology – Heart and Circulatory Physiology. Future work will be needed to affirm that there may be a cause and effect relationship between flexibility and artery and veins stiffness. Until we know more, consider the benefits of adding stretching exercises, yoga or Pilates to your fitness routine (with your doctor’s okay, of course) and see how you feel. It can’t hurt, and may help more than you know.