AEROBIC EXERCISE IN PREGNANCY - AN UPDATE

The endocrine effects of pregnancy cause striking changes in maternal metabolism, cardiovascular regulation, acid-base balance, and thermore gulation at rest and during standard submaximal exercise. The apparent purpose of these changes is to accommodate fetal needs in addition to those of the exercising woman. A significant body of evidence support s the hypothesis that healthy women can perform acute exercise of mode rate intensity and duration without jeopardizing fetal well-being. Com piled studies also suggest that maximal oxygen uptake (VO2max, L.min-1 ) and the work rate at the onset of blood lactate accumulation (OBLA) are not significantly altered during the course of a normal pregnancy. However, some evidence suggests that maximal anaerobic power may be r educed. More information is needed on maternal cardiorespiratory funct ion, carbohydrate metabolism, and acid-base balance at exercise intens ities above OBLA and on fetal adaptability to strenuous maternal exerc ise. Recent studies support the view that moderate fitness conditionin g can augment maternal metabolic and cardiopulmonary capacities withou t altering fetal development or pregnancy outcome. Implications of rec ent scientific studies for the design of aerobic exercise programs for pregnant women are discussed.