[Changes in blood pressure during static work. Practical implication].

Abstract

while the cardiocirculatory response to dynamic exercises (e.g. running, cycling, swimming) is the object of the physician's full attention, the cardiovascular repercussions of static exercises, such as weight-lifting, sustained postures in gymnastics or immobilization in judo, are often ignored. Yet any sustained isometric contraction is associated from the art with an increase in blood pressure which may be major and involves about equally the systolic and diastolic pressures. As soon as the strength developed by the muscle exceeds 20 p. 100 of its maximum voluntary strength (MVS) the increase of blood pressure continues until the contraction comes to an end. Whatever the muscle used, the intensity of a cardiovascular response is independent of the muscular mass in action, but it mostly depends on the MVS percentage This rise in blood pressure is mainly due to an increase in heart and cardiac output. The reactions are such that relatively moderate and localized static effort may result in a rapid and important increase in myocardial work, and this may cause serious accidents in subject with a cardiovascular weakness, either isolated or associated with such risk factors as age or arterial hypertension. In consequence, adults who are insufficiently trained and present with one or several risk factors should avoid sports which required frequent respiratory arrests and/or sustained postures. If such sports are nevertheless chosen, it would seem that practising also a dynamic sport relying on aerobic metabolism might lin , at least in part, the effects of increased blood pressure due to static activities.