Sex efficiency through exercises : special physical culture for women / by Th. H. van de Velde ; [photos, by E. Steinemann].

whole register of " degrees " from activity to passivity, as suits the individual. I recommend a certain degree of care and moderation in all leg exercises carried out in the upright posture : avoid abrupt and vehement jerks from hip or knee. Rapid and vigorous centrifugal movements of this kind have a bad effect on the circulation, especially if they are complicated by the need to preserve balance, as is the case when standing. So they should only be employed in exceptional cases during pregnancy, where there are specially favourable individual conditions, and then only with due caution. As a rule, a slight and gentle pendulum movement of the leg suffices, and even this should not be continued if symptoms of circulatory disturbance are perceptible (such as a heavy sensation and swollen veins). More vigour may be put into the leg exercises—at least the centrifugal, i.e., those in which the direction of movement is from the centre of the body outwards, if performed lying at full length, as in the rotation and the " scissors " exercises. In such cases the force of gravitation does not combine with the centrifugal impetus to hinder the flow of blood back from the extremities to the heart, but it counteracts the latter, so that recumbent exercises entail much less risk of vascular congestion. On the other hand, the recumbent posture has the dis- advantage of taxing the abdominal muscles more or less heavily. The degree of strain depends on the kind of exercise chosen and the mastery of delicate and slight gradations of exertion. Some previous training and proficiency are very helpful here. And doubtless some exercise, even vigorous exercise of the muscles of the abdominal wall during pregnancy is no disadvantage; on the contrary, their increased tonicity and control is very desirable. But—as has been already stressed in these pages—the exercise must alternate effort with relaxation at will and not be entirely effort; the muscles must be tensed or loosened rhythmically, and the effort should not be too prolonged and should be restricted to the most suitable times and seasons. We must deal more in detail with these times and seasons,