Maternal and fetal responses to a maternal aerobic exercise program. The effect of participation in a regular exercise program upon aerobic capacity during pregnancy. Exercise during pregnancy improves maternal health perception: a randomized controlled trial. Aerobic exercise and submaximal functional capacity in overweight pregnant women: a randomized trial. Physical and psychological changes with vigorous exercise in sedentary primigravidae. Heart volume and physical fitness of parturients. A randomized study of the effects of aerobic exercise by lactating women on breast-milk volume and composition. Continuing regular exercise during pregnancy: effect of exercise volume on fetoplacental growth. Effect of exercise on blood pressure in pregnant women with a high risk of gestational hypertensive disorders.
To investigate the effects of exercise on the pregnant woman and her fetus, 20 pregnant women were studied during the second and third trimesters. Twelve of the women participated in an aerobic exercise program while eight women did not perform any regular exercise and served as a control group. On the basis of submaximal exercise test results, an 18% improvement and a 4% decline in absolute aerobic capacity (liters of oxygen per minute) were observed in the exercise and control groups, respectively. Functional aerobic capacity (milliliters of oxygen per kilogram per minute) rose 8% in the exercise group and declined 10% in the control group. A small but significant rise in fetal heart rate was measured during the exercise sessions. A comparison of pregnancy outcome of the two groups showed no differences in labor duration, Apgar scores, or fetal growth. This study examined the questions of whether pregnancy decreases physical fitness, as measured by maximal oxygen consumption, between the second and third trimesters, and whether maintaining a regular exercise program during the second half of pregnancy affects fitness. At the beginning of their second trimester, pregnant women were randomly assigned to either a nonexercising control group or an exercising group. They completed a maximal progressive exercise test on a cycle ergometer at 20 and 30 weeks, during which pulmonary parameters of aerobic capacity were measured. The exercising group demonstrated greater improvement in aerobic capacity than did the control group, manifested by increases in tidal volume and oxygen consumption and a stable ventilatory equivalent for oxygen. Pregnancy did not reduce maximal oxygen consumption between the second and third trimesters of pregnancy. We have studied the effect of moderate physical activity that is performed by healthy women during their entire pregnancy on their perception of health status.
                Eighty sedentary women were assigned randomly to either an exercise group (n = 40) or a control group (n = 40). Maternal perception of health status and several pregnancy outcomes were recorded.
                Significant differences (P = .03) were found between study groups in the percentage of women who perceived their health status as "very good"; the values that corresponded to the exercise group (n = 18; 54.5%) were better than those of the control group (n = 9; 27.3%). In addition, the women of the exercise group gained less weight (11,885 ± 3146 g) than those of the control group (13,903 ± 2113; P = .03).
                A moderate physical activity program that is performed over the first, second, and third trimester of pregnancy improves the maternal perception of health status.
                Copyright © 2011 Mosby, Inc. All rights reserved. To evaluate the effects of aerobic training on submaximal cardiorespiratory capacity in overweight pregnant women.
                We conducted a randomized clinical trial in a referral center prenatal clinic during the period 2000-2002. Of 132 overweight (body mass index 26-31 kg/m2) but otherwise healthy volunteers, at 20 years of age or older, with gestational age of 20 weeks or less, and without diabetes or hypertension, 92 consented to participate and were randomized. Intervention consisted of 3 one-hour aerobic exercise sessions per week; the control group received weekly relaxation and focus group discussions. The main outcome measure was submaximal exercise capacity evaluated by oxygen uptake at the anaerobic (first ventilatory) threshold during cardiopulmonary treadmill testing 12 weeks after randomization.
                Oxygen uptake at the anaerobic threshold increased 18% (15.9 +/- 2.6 to 18.1 +/- 3.1 mL . min(-1) . kg(-1)) in the exercise group but decreased 16% (16.9 +/- 3.0 to 15.8 +/- 2.6 mL . min(-1) . kg(-1)) among the control group. Oxygen consumption at the anaerobic threshold, adjusted through analysis of covariance for baseline oxygen uptake, was 2.68 (95% confidence interval 1.23 to 4.12) mL . min(-1) . kg(-1) greater in the exercise group. Women in the exercise group were approximately 5 times more likely than those in the control group to have regular or good cardiorespiratory capacity (12/38 versus 2/38; relative risk 5.2, 95% confidence interval 1.2 to 22.0, number needed to treat 5).
                Aerobic training in overweight pregnant women substantially increases submaximal exercise capacity, overcoming the otherwise negative effects of pregnancy in this regard. Additional studies are required to evaluate its effect on major clinical outcomes. The present study examined the effects of exercise on physical and psychological variables in sedentary primigravidae (PRA).
                A total of nine women randomly assigned to an exercise (E) (mean age = 31.3 +/- 3.1 yr) and six subjects randomly assigned to a control (C) group (mean age = 27.8 +/- 3.1 yr) fulfilled all requirements for the study. Exercise included a variety of exercise activities performed to a target heart rate of 150-156 beats x min(-1), three times per week for 15 wk.
                Results showed no significant differences between E and C groups in physical characteristics initially. A repeated measures ANOVA showed a significant group effect (P < 0.05) and a significant group by time interaction (P = 0.001) with the E group showing a significantly longer amount of time on the PWC150 test than the C group. There was no significant group, time, or group by time interaction for lactate accumulation. This occurred, despite the fact that the E group spent 56% longer on the PWC150 test and the C group spent 30% less time on the same test at the conclusion of the study. Finally, the E group in comparison to the C group showed more favorable improvements in several items related to health and well-being on the Body Cathexis Scale. There were no significant differences between E and C groups in any pregnancy outcome measures. All babies were delivered healthy at term.
                These data suggest that a vigorous exercise program can lead to significant improvements in aerobic fitness at similar lactate concentrations compared to a control group and can be well tolerated by low risk sedentary PRA without any deleterious effects occurring to herself or unborn child. One hundred and three primigravidae were studied to establish the correlation between physical fitness and heart volume. Twenty-three of the mothers were allocated at random to the exercise group and 21 to control group 1, between the 10th and 14th weeks of pregnancy. In addition, 59 mothers were allocated to control group 2, which was formed two weeks before term. The exercise group underwent a rather strenuous training programme during pregnancy. Physical fitness was measured by work tests on a bicycle ergometer two weeks before term. The heart volume was determined radiologically on the 6th day post partum. There was a positive correlation between physical fitness and the relative heart volume, which was greatest when physical fitness was measured by a method which takes the level of training into consideration. The relative heart volume of the exercise group was almost significantly greater than that of control group 1. The physical performance of the exercise group was very significantly greater than in the control groups. There was no significant correlation between either physical fitness or relative heart volume and the duration of pregnancy or the weight of newborn. The potential risks and benefits of regular exercise during lactation have not been adequately evaluated. We investigated whether regular aerobic exercise had any effects on the volume or composition of breast milk.
                Six to eight weeks post partum, 33 sedentary women whose infants were being exclusively breast-fed were randomly assigned to an exercise group (18 women) or a control group (15 women). The exercise program consisted of supervised aerobic exercise (at a level of 60 to 70 percent of the heart-rate reserve) for 45 minutes per day, 5 days per week, for 12 weeks. Energy expenditure, dietary intake, body composition, and the volume and composition of breast milk were assessed at 6 to 8, 12 to 14, and 18 to 20 weeks post partum. Maximal oxygen uptake and the plasma prolactin response to nursing were assessed at 6 to 8 and 18 to 20 weeks.
                The women in the exercise group expended about 400 kcal per day during the exercise sessions but compensated for this energy expenditure with a higher energy intake than that recorded by the control women (mean [+/- SD], intake, 2497 +/- 436 vs. 2168 +/- 328 kcal per day at 18 to 20 weeks; P < 0.05). Maximal oxygen uptake increased by 25 percent in the exercising women but by only 5 percent in the control women (P < 0.001). There were no significant differences between the two groups in maternal body weight or fat loss, the volume or composition of the breast milk, the infant weight gain, or maternal prolactin levels during the 12-week study.
                In this study, aerobic exercise performed four or five times per week beginning six to eight weeks post partum had no adverse effect on lactation and significantly improved the cardiovascular fitness of the mothers. The purpose of this study was to test the null hypothesis that the volume of exercise at different times during pregnancy has no effect on fetoplacental growth.
                Seventy-five women who exercised regularly were evaluated before pregnancy and randomly assigned at 8 weeks' gestation to one of 3 exercise regimens for the remainder of pregnancy. Primary outcome variables included placental growth rate, birth weight, and placental volume at term.
                The offspring of the women who were randomly assigned to a high volume of exercise in mid and late pregnancy were significantly lighter (3.39 kg vs 3.81 kg) and thinner (8.3% fat vs 12.1% fat) than those offspring born of women who were randomly assigned to reduce their exercise volume after the 20th week. Maternal weight gain, fresh placental volumes, and histomorphometric indices of placental function were greater in the high-low group.
                These data indicate that a high volume of moderate-intensity, weight-bearing exercise in mid and late pregnancy symmetrically reduces fetoplacental growth, whereas a reduction in exercise volume enhances fetoplacental growth with a proportionally greater increase in fat mass than in lean body mass. To prospectively determine whether moderate exercise during pregnancy lowers blood pressure.
                A randomized, controlled trial with one test group and one control group. All subjects have a history of mild hypertension, gestational hypertensive disorders or a family history of hypertensive disorders. Subjects were recruited before 14 weeks' gestation. After four weeks of observation, the subjects were randomly assigned to either the exercise or control group. The exercise group visited the laboratory three times a week for 10 weeks (18-28 gestation weeks) to perform 30 minutes of exercise at Rating of Perceived Exertion level 13.
                A total of 16 pregnant women (mean age, 30 years) participated. The mean metabolic equivalent during exercise sessions was 4.7 (SD = 0.8). Blood pressure measurements were compared before and after the 10-week exercise period in the two groups. Systolic blood pressures did not change significantly, but diastolic blood pressure (DBP) in the exercise group decreased by 3.5 mm Hg, while that in the control group increased by 1.1 mm Hg. Thus, the pre-post change in DBP differed by 4.6 mm Hg between groups. Exercise treatment reduced the diastolic blood pressure to a near-significant level in the exercise group (t = 2.34, df = 7, P = .052). Percent body fat did not differ between the exercise and control groups either before or after exercise treatment. ANOVA revealed that pregnancy had a significant effect (F(1, 14) = 5.7, P = .03) on increasing the percentage of fat, but exercise treatment did not (F(1, 14) = .18, P = .68). Estimated energy expenditure in overall daily physical activities during the intervention did not differ between the two groups despite the inclusion of exercise.
                This study detected a strong trend that 10 weeks of moderate exercise lowered the diastolic blood pressure among pregnant women at risk of hypertensive disorders. The reductions were probably due to the effect of exercise itself, not to weight or overall daily physical activity levels.
Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness. Available data are insufficient to infer important risks or benefits for the mother or infant. Larger and better trials are needed before confident recommendations can be made about the benefits and risk of aerobic exercise in pregnancy.