The mystery behind the cause of "exercise hypertension" may be solved, according to a study reported in the American Journal of Hypertension (April 2004). Exercise hypertension is an abnormally high spike in blood pressure that happens in normally healthy individuals when they exercise. While exercise hypertension is a known risk factor for permanent and serious high blood pressure at rest, the cause of this condition has been unclear.
The results suggested that it may be caused by the failure of endothelial cells that line the blood vessels to allow the arteries to open wider to make room for the increased blood flow that occurs during exercise. "Our study shows that impaired ability of the endothelial cells, which control large blood vessel relaxation, is a potential cause of exercise hypertension," said study author Kerry J. Stewart, EdD, MEd, MA.