Here is another reason to work on your flexibility: For people over 40, how flexible the body is may also show how healthy the arteries are. There is a simple way to measure body flexibility, according to the Japanese researchers who studied this relationship.Sit on the floor with your back against the wall, legs extended, and then lean forward and see how far you can reach with your arms toward your feet. The farther, the better. It's called the sit and reach test.

Healthy arteries are flexible and elastic. They get progressively stiffer as people age. Arterial stiffness is a risk factor for cardiovascular disease and death. The Japanese study suggests that age−related arterial stiffening can be delayed by maintaining a flexible body.

Interestingly, neither the cardio−respiratory fitness of those over 40 (as measured by performance on a stationary bike) nor their muscular strength was related to arterial stiffness.

The sit and reach test measures the flexibility of a person's trunk (midsection). This is an indication of the flexibility of the entire body.

The researchers studied 526 healthy adults whose ages ranged from 20 to 83. None were obese or smoked. Trunk flexibility was measured by the distance participants could reach in the sit and reach test. To determine arterial stiffness, the speed of a pulse of blood from ankle to arms and from leg to neck was measured. As with water flowing in a garden hose, the stiffer the arteries, the faster the blood flows.

Those over 40 with poor trunk flexibility had stiffer arteries than those with good trunk flexibility. They also had higher systolic blood pressure. These associations were not seen in people younger than 40. Interestingly, neither the cardio−respiratory fitness of those over 40 (as measured by performance on a stationary bike) nor their muscular strength was related to arterial stiffness.

For middle aged subjects, poor flexibility was a reach of about 12 inches, while high flexibility was a reach of about 18 inches. For older adults, the numbers were about 10 and 16 inches. This is starting from a position with the arms held out straight. The researchers used both a testing attendant and a digital measuring device, so any in home measurements should be taken with a grain of salt.

While the study links poor body flexibility in older individuals to stiffer arteries, it only suggests that maintaining good body flexibility will help keep the arteries flexible. Establishing a cause−and−effect relationship will require further studies.

Despite the newness of their findings, the researchers feel that they're on to something. They point to another recent study that found that middle−aged and older adults who began a regular program of stretching also improved the flexibility of their carotid artery as additional evidence that flexible bodies mean flexible arteries. They suggest that flexibility exercises such as stretching, yoga and Pilates should be made a part of all exercise guidelines and recommendations.

The study was conducted by researchers from the National Institute of Health and Nutrition in Tokyo and from Waseda University. An article detailing the study was published in the October 2009 issue of the American Journal of Physiology—Heart and Circulatory Physiology. It's freely available at http://ajpheart.physiology.org/cgi/content/abstract/297/4/H1314.