Dynamic exercise in human pregnancy

This thesis represents an effort to obtain a better understanding of the ability of pregnant women to perform aerobic exercise. It consists of four chapters. Chapter 2 describes a longitudinal study of maximal power and oxygen uptake in pregnant and postpartum women. Because only a limited amount of energy can be produced anaerobically, the ability of a person to perform exercise oflonger duration depends largely on the capacity of aerobic energy production. Therefore, maximal oxygen uptake is the best indicator of an individual's ability to perform endurance exercise. It can be measured reliably and reproducibly with little inconvenience to the person tested, except for the strain of maximal exercise. In order to determine the effect of pregnancy weight gain, the women were studied both on the bicycle ergometer (nonweightbearing exercise), and on the treadmill (weightbearing exercise). Chapter 3 reports on the safety aspects relevant to the mother and the fetus: maternal electrocardiogram and blood pressure, uterine contractility, and fetal heart rate. Chapter 4 deals with errors and inaccuracies of estimated values of maximal oxygen uptake in pregnant women. Fetal health concerns have limited most exercise testing during pregnancy to submaximal exercise intensities. However, the validity of the methods that have been used to estimate maximal oxygen uptake from submaximal values has not been determined. Finally, Chapter 5 extensively reviews the literature on physiological adaptations which occur in dynamic exercise and pregnancy, and discusses practical implications and guidelines for women who wish to perform sport activities during pregnancy