Endpoints of chronobiologic cardiovascular monitoring during pregnancy for planning exercise and assessing effects.

The chronobiologic question is raised whether exercise may be indicated for the pregnant woman as a general prophylactic measure and, if so, whether it should be timed according to rhythms and stage of pregnancy. This question, recently considered by others without chronobiologic focus, is here reviewed against the background of results from ongoing chronobiologic studies of blood pressure (BP) and heart rate (HR) in pregnancy. During pregnancy, the MESORs and circadian amplitudes of systolic (S), mean arterial (MA) and diastolic (D) BP are correlated with a questionnaire-assessed cardiovascular risk score. Such results were found under noisy ordinary conditions of life without accounting for effects of activity. They are group results, and as such require further work before they can contribute to identifying individuals at high risk in particular need of intervention, such as exercise. The dependence of exercise effects upon circadian rhythms should also prompt the use of rhythmometry at all ages for timing exercise, for gauging its effects and eventually for the optimization of fitness training for the population as well as for peak performance.