Gretchen Reynolds in the New York Times Magazine:
Sit on the floor with your legs stretched straight out in front of you, toes pointing up. Reach forward from the hips. Are you flexible enough to touch your toes? If so, then your cardiac arteries probably are also flexible.
In the study’s experiment, scientists from the University of North Texas and several Japanese universities recruited 526 healthy adults between the ages of 20 and 83 and had them perform the basic sit-and-reach test described above, although their extensions were measured precisely with digital devices. Taking into account age and gender, researchers then sorted the subjects into either the high-flexibility group or the poor-flexibility group.
Next, using blood-pressure cuffs at each person’s ankles and arms, researchers estimated how flexible their arteries were. Cardiac artery flexibility is one of the less familiar elements of heart health. Supple arterial walls allow the blood to move freely through the body. Stiff arteries require the heart to work much harder to force blood through the unyielding vessels and over time could, according to Kenta Yamamoto, a researcher at North Texas and lead author of the study, contribute to a greater risk for heart attack and stroke.
What the researchers found was a clear correlation between inflexible bodies and inflexible arteries in subjects older than 40.