Prenatal Exercise Intervention Research Articles

Effects of prenatal exercise interventions on maternal body composition: A secondary analysis of the FitMum randomized controlled trial.

The main objective of the study was to investigate the effects of prenatal exercise interventions on maternal body composition at 28 weeks gestation and 7-14 days after delivery. We also explored associations between physical activity (PA) per se and body composition. This study presents secondary outcomes of the FitMum randomized controlled trial, which included healthy inactive pregnant women at gestational age ≤ 15+0 weeks. They were randomized to structured supervised exercise training, motivational counselling on PA, or standard care. Maternal body composition was measured by doubly labeled water at 28 weeks gestation (n = 134) and by dual-energy X-ray absorptiometry scan 7-14 days after delivery (n = 117). PA, including moderate-to-vigorous-intensity PA (MVPA), active kilocalories, and steps, were measured continuously from inclusion to delivery by a wrist-worn activity tracker. One hundred fifty pregnant women were included with a median pre-pregnancy body mass index (BMI) of 24.1 (21.6-27.9) kg/m2. We found no differences between groups in fat mass, fat percentage or fat-free mass at 28 weeks gestation or 7-14 days after delivery. Visceral adipose tissue mass and bone mineral density measured 7-14 days after delivery did not differ between groups either. Linear regression analyses adjusted for pre-pregnancy BMI showed that a higher number of daily steps was associated with lower fat mass, fat percentage, and visceral adipose tissue mass at 28 weeks gestation and 7-14 days after delivery. Active kilocalories during pregnancy was positively associated with fat-free mass 7-14 days after delivery. Neither structured supervised exercise training nor motivational counselling on PA during pregnancy affected maternal body composition at 28 weeks gestation or 7-14 days after delivery compared to standard care. Interestingly, when adjusted for pre-pregnancy BMI, higher number of daily steps was associated with lower fat content during pregnancy and after delivery, whereas MVPA and active kilocalories were not. Trial registration: ClinicalTrials.gov; NCT03679130; 20/09/2018.

Population characteristics associated with adherence to prenatal group-based exercise programs

ABSTRACT Community-based supervised group exercise may be an effective option to increase activity levels throughout pregnancy. Previous studies that have explored predictors of low adherence to exercise during pregnancy have not examined group-based settings. We analysed an international cohort of 347 pregnant women who participated in group-based prenatal exercise interventions (from <20 weeks to 34–36 weeks pregnant). Probable adherence predictors informed by previous literature that were assessed included: pre-pregnancy physical activity level and body mass index (BMI) classification, age, number of previous pregnancies, and education level. Adherence was measured by attendance. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated to explore the relationship between the selected predictors and high adherence (≥70%). Post-secondary education level versus only secondary (aOR 5.28; CI 1.67; 16.72) or primary level (aOR 13.82; CI 4.30; 44.45) presented greater likelihood to have high adherence to the exercise intervention than low adherence. Future research and public health initiatives should consider implementing strategies to overcome education-related barriers to improve accessibility to prenatal exercise.

Influence of exercise type on maternal blood pressure adaptation throughout pregnancy

BACKGROUNDIt has been reported that 10% of all pregnancies are complicated by a hypertensive disorder of pregnancy. Previous research has shown that moderate-vigorous intensity exercise has a positive effect on maternal resting blood pressure. A research gap, however, exists related to how different types of exercise (resistance, aerobic, combined resistance and aerobic) affect maternal blood pressure. Most of the previous studies solely focused on aerobic exercise.OBJECTIVEThe aim of this study was to examine the effects of exercise types on maternal blood pressure throughout pregnancy.STUDY DESIGNThis study employed a secondary analysis using data from a randomized controlled prenatal exercise intervention trial. This study utilized 3 exercise intervention groups (aerobic, resistance, combination) and compared the results with those of a nonexercize control group. Participants completed 3 50-minute sessions weekly from 16 weeks of gestation until delivery. Maternal vital signs and physical measurements such as systolic blood pressure, diastolic blood pressure, and heart rate were measured every 4 weeks throughout the intervention period. Between-group mean differences in maternal measurements were assessed using Pearson's chi-square tests for continuous (age, prepregnancy body mass index, heart rate, systolic blood pressure, diastolic blood pressure, pulse pressure) variables. For gravida, exact Wilcox 2-sample tests were performed to determine between-group differences in mean values. Hierarchical linear growth curves were used to estimate maternal trajectories of systolic blood pressure and diastolic blood pressure from 16 weeks to 36 weeks’ gestation in each of the 4 groups (aerobic, combination, control, and resistance).RESULTSThere were no differences among the groups in maternal age or prepregnancy body mass index. Controlling for maternal body mass index, the lowest significant systolic blood pressure curve was noted throughout the pregnancy for women who participated in resistance exercise, followed by women in the aerobic exercise group all relative to the no exercise control group. At 36 weeks’ gestation, the systolic blood pressure was lower in the resistance group by 12.17 mm Hg (P<.001) and in the aerobic group by 7.90 mm Hg (P<.001) relative to controls. No significant change in systolic blood pressure was noted in the combination group in comparison with controls at 36 weeks’ gestation. Similarly, we demonstrated a significantly lower linear growth curve in diastolic blood pressure that was maintained throughout pregnancy in any exercise type relative to controls. After controlling for maternal body mass index, all 3 exercise types (combination, resistance, and aerobic) significantly predicted a similar decrease in diastolic blood pressure that was maintained throughout pregnancy. At 36 weeks’ gestation, the diastolic blood pressure was lower in the aerobic group by 7.30 mm Hg (P<.01), in the combination group by 6.43 mm Hg (P<.05), and in the resistance group relative to controls.CONCLUSIONOverall, all exercise types were beneficial in lowering maternal resting blood pressure throughout pregnancy. Resistance training was noted to be the most beneficial in improving systolic blood pressure, followed by aerobic exercise. All 3 exercise groups were noted to improve diastolic blood pressure equally. Further research needs to be done to determine if either resistance or aerobic exercise throughout pregnancy decreases the risk for hypertensive disorders of pregnancy and the associated morbidity and mortality.

The effects of aerobic exercise on markers of maternal metabolism during pregnancy.

Optimal maternal metabolism during pregnancy is essential for healthy fetal growth and development. Chronic exercise is shown to positively affect metabolism, predominantly demonstrated in nonpregnant populations. To determine the effects of aerobic exercise on maternal metabolic biomarkers during pregnancy, with expected lower levels of glucose, insulin, and lipids among exercise-trained pregnant women. Secondary data analyses were performed using data from two, longitudinal prenatal exercise intervention studies (ENHANCED by MOM and GESTAFIT). Exercisers completed 150 min of weekly moderate-intensity exercise during pregnancy (24+ weeks) while nonexercisers attended stretching sessions. Pregnant women were 31-33 years of age, predominantly non-Hispanic white, and "normal weight" body mass index. At 16 and 36 weeks of gestation, fasting blood samples were collected via fingerstick and venipuncture. Maternal glucose, insulin, insulin resistance (HOMA-IR), total cholesterol (TC), low-density lipoproteins (LDL), high-density lipoproteins (HDL), and triglycerides (TG) were analyzed. ANCOVA analyses were performed to evaluate the effects of aerobic exercise on markers of maternal metabolism in late pregnancy, controlling for baseline levels. Our sample included 12 aerobic exercisers and 54 nonexercising control groups. Significant between-groups differences at 16 weeks of gestation were found for TG (92.3 vs. 121.2 mg/dl, p = .04), TC (186.8 vs. 219.6 mg/dl, p = .002), and LDL (104.1 vs. 128.8 mg/dl, p = .002). Aerobic-trained pregnant women exhibited lower insulin levels in late pregnancy (β = -2.6 μIU/ml, 95% CI:-4.2, -0.95, p = .002) and a reduced increase in insulin levels from 16 to 36 week of gestation (β = -2.3 μIU/ml, 95% CI: -4.4, -0.2, p = .034) compared with nonexercising pregnant women. No statistically significant effects were observed for maternal HOMA-IR, TC, LDL, HDL, TC:HDL, and TG in late pregnancy. The observations of this study demonstrate that prenatal exercise may positively affect maternal insulin, with aerobic-trained pregnant women exhibiting lower insulin levels in late pregnancy. Additionally, we found no appreciable effects of prenatal exercise on maternal lipids in late pregnancy.

Association of Fitness Level Early in Pregnancy with Compliance Toward an Exercise Intervention Throughout Gestation in Obese Women

Abstract Objectives Low participant compliance with prenatal exercise trials can result in loss of power to detect intervention effects. The objective of this study was to assess the association of aerobic capacity at enrollment with compliance with an exercise intervention throughout gestation. Methods Fifty-nine sedentary women with obesity who participated in the exercise arm of a randomized controlled trial were assessed at gestation week 12, and compliance was monitored throughout gestation. Fat-free mass index (FFMI, kg/m2) was obtained by DXA and measured height. Submaximal VO2 (Borg score of 15) was measured using an incremental treadmill protocol. VO2 was normalized to FFMI (ml·min−1· FFMI−1). A VO2 cutoff of ≥112.7 (Q3 to highest data point) or ≤69.4 (Q1 to smallest data point) was used to classify women as “High” (n = 17) or “Low” (n = 17) fitness. Compliance (%) was estimated using the date of first exercise and delivery date, assuming a goal of 3 exercise sessions per week. Education level and birth weight were self-reported, whereas gestational weight gain (GWG), and gestational age (GA) were calculated. Results Groups were similar in BMI and LBMI at enrollment. The proportion of women with a college degree differed between groups (High = 100% vs. Low = 29%, P &amp;lt; .0001), and there was interaction between baseline fitness level (VO2) and education level (P = 0.004) in predicting compliance to the exercise intervention. For women with a college degree, there was no difference in compliance between high and low fitness groups (72 ± 5% vs. 60 ± 10%, P = NS). However, compliance was lower in women in the Low group with high school degree than in women in the High group (52 ± 6% vs.72 ± 5%, P = 0.0244). There were no impact of education on compliance for the low fitness group. GWG, GA and birth-weight were similar between groups (P = NS). Conclusions In these preliminary analyses, there was an interaction between fitness and education level on compliance with a prenatal exercise intervention. Compliance was about 20 percentage points lower in women with lower fitness and lower education when compared to women with higher fitness and higher education at enrollment. Funding Sources USDA-ARS Project 6026–51,000-012–06S.

Prenatal Exercise and Cardiorespiratory Health and Fitness: A Meta-analysis

This study aimed to examine the influence of prenatal exercise on maternal cardiorespiratory health and fitness during pregnancy. Online databases were searched up to February 25, 2019. Studies of randomized controlled trials (RCTs) were eligible, which contained information on the relevant population (pregnant women), intervention (subjective or objective measures of frequency, intensity, duration, volume, or type of exercise), comparator (no exercise intervention), and outcomes (maternal cardiorespiratory fitness, including V˙O2max, submaximal V˙O2, V˙O2 at anaerobic threshold, and cardiorespiratory health, including resting heart rate, and resting systolic and diastolic blood pressures during pregnancy). From 2699 unique citations, 26 RCTs (N = 2292 women) were included. Of these, one study reported measured V˙O2max, seven reported predicted V˙O2max, three reported submaximal V˙O2, and two studies reported VO2AT. "Low"- to "high"-certainty evidence revealed that exercise was associated with improved predicted/measured V˙O2max (5 RCTs, n = 430; mean difference [MD], 2.77 mL·kg·min; 95% confidence interval [CI], 0.32 to 5.21 mL·kg·min; I = 69%), reduced resting heart rate (9 RCTs, n = 637; MD, -1.71 bpm; 95% CI, -3.24 to -0.19 bpm; I = 13%), resting systolic blood pressure (16 RCTs, n = 1672; MD, -2.11 mm Hg; 95% CI, -3.71 to -0.51 mm Hg; I = 69%), and diastolic blood pressure (15 RCTs, n = 1624; MD, -1.77 mm Hg; 95% CI, -2.90 to -0.64 mm Hg; I = 60%). Prenatal exercise interventions improve maternal predicted/measured V˙O2max and reduce resting heart rate and blood pressure. This review highlights the need for additional high-quality studies of cardiorespiratory fitness (namely, V˙O2max and V˙O2 peak) in pregnancy.PROSPERO registration number: CRD42019131249.

Long-term effects of participation in a prenatal exercise intervention on body weight, body mass index, and physical activity level: a 6-year follow-up study of a randomized controlled trial

Background Growing evidence supports that physical activity and exercise during pregnancy is favorable for the mother, with persisting benefits in the postpartum period. However, there is scant knowledge of the effect of a prenatal exercise program on long-term health and lifestyle habits. Objectives This 6-year follow-up study of a randomized controlled trial had two aims: (1) compare body weight, weight retention and body mass index (BMI) in the intervention group and control group, and (2) evaluate effects on physical activity level and recreational exercise. Materials and methods Out of 105 participants initially randomized to either an intervention group, n = 52 (twice weekly group-exercises and physical activity counselling) or control group, n = 53 (standard prenatal care), 80 women (76.2%) participated in the present long-term follow-up study, performed in a general community in Oslo, Norway. Data were collected through a standardized telephone interview based on the baseline protocol and a modified Physical Activity and Pregnancy Questionnaire (PAPQ). Body weight at 6 years follow-up was self-reported (kg), and calculation of current BMI (kg/m2) was based on self-reported weight and measured height at study inclusion. Investigators were unaware of the original randomization at the time of the interviews. Analyses of covariance were used to examine the difference in change in body weight and BMI between the groups. Even though the MET-values were not normally distributed, differences were examined using a two-sided independent sample t-test due to large sample size (n ≥ 30). Results At 6 years follow-up there were no differences in mean BMI (kg/m2) (24.0 ± 3.8 versus 24.8 ± 4.0, p = .37), physical activity level (4167 ± 2638 versus 3925 ± 3075 MET-min/week, p = .67) or recreational exercise (630 ± 1290 versus 720 ± 1005 MET-min/week, p = .88) between the intervention and control group, respectively. Subgroup analysis of participants with high adherence during the intervention 6 years ago (≥24 prenatal exercise classes), showed a positive intervention effect at long-term follow up in body weight (kg) (62.8 ± 7.9 versus 70.8 ± 11.8, p = .03) and BMI (kg/m2) (22.5 ± 3.1 versus 24.8 ± 4.0, p = .05), and none (versus 11 in the control group) had gained ≥5 kg compared to prepregnancy weight (p = .02). Conclusions Women who adhered to the original prenatal exercise intervention demonstrated significantly lower body weight and BMI at 6-year follow-up. Otherwise, no long-term intervention effect was observed.

Exploring Prenatal Physical Activity at the “Postgenomic Turn”: A Transdisciplinary Journey

Within the life sciences, there has been a move away from genetic determinism toward an awareness of how the environment (from cellular to social) can impact gene expression and health outcomes. Significantly, exercise scientists are looking to this “postgenomic turn” to explore how prenatal physical activity and leisure might affect the fetal metabolic environment by altering offspring gene expression and preventing future obesity. In this article, we draw upon insights from feminist new materialist scholars to explore how and if the entanglement of the social and material promised by the postgenomic turn is realized in prenatal exercise interventions. After outlining how this is not the case, we reflect upon our attempt to promote a transdisciplinary dialogue that facilitates a social justice ethos and nonreductionist version of maternal-fetal health and physical culture. Our transdisciplinary journey contributes to the feminist physical cultural studies agenda of equity development in the realm of exercise and leisure.

Effects of physical exercise during pregnancy on maternal and infant outcomes in overweight and obese pregnant women: A meta-analysis.

Overweight and obesity are related to maternal and infant physical health, such as gestational diabetes, preeclampsia, and macrosomia. The purpose of this meta-analysis was to assess the effect of physical exercise on maternal and infant outcomes in overweight and obese pregnant women. Two researchers independently searched Cochrane Library, Embase, PubMed, Web of Science, and ClinicalTrials.gov. for English-language articles based on randomized controlled trials examining physical exercise in overweight and obese pregnant women and its effect on maternal and infant outcomes. Primary outcomes were gestational weight gain and a relative risk of gestational diabetes. Secondary outcomes were gestational hypertension, preeclampsia, cesarean delivery, birthweight, large for gestational age, small for gestational age, macrosomia, and preterm birth. Risk bias was evaluated by Cochrane Collaboration's tool. The results of integration were reported as relative risks (RR), mean difference, or standard mean difference with 95% confidence intervals (CI). This meta-analysis was registered on PROSPERO on November 18, 2017, with registration number CRD42017081565. Thirteen studies involving 1439 participants were included. Physical exercise reduced gestational weight gain (mean difference=-1.14kg, 95% CI=[-1.67 to -0.62], P<0.0001) and the risk of gestational diabetes (RR=0.71, 95% CI=[0.57-0.89], P=0.004) in overweight and obese pregnant women. There were no significant differences in other outcomes such as gestational hypertension, preeclampsia, cesarean delivery, birthweight, large for gestational age, small for gestational age, macrosomia, and preterm birth. Prenatal exercise interventions reduced gestational weight gain and the risk of gestational diabetes for overweight and obese pregnant women, which reinforced the benefits of exercise during pregnancy. However, no evidence was found with respect to benefits and/or harm for infants. Consideration should be taken when interpreting these findings as a result of the relative small sample size in this meta-analysis. Further larger well-designed randomized trials may be helpful to assess the short-term and long-term effects of prenatal exercise on maternal and infant outcomes.

The Effect of an Exercise Intervention on Gestational Weight Gain: The Behaviors Affecting Baby and You (B.A.B.Y.) Study: A Randomized Controlled Trial.

To examine the effect of a prenatal exercise intervention on gestational weight gain (GWG) and to update meta-analyses. Randomized controlled trial and meta-analysis. Obstetrical practices in a Western Massachusetts hospital. We analyzed 241 ethnically diverse pregnant participants at high risk for gestational diabetes in the Behaviors Affecting Baby and You (B.A.B.Y.) study. A total of 118 participants were randomized to an exercise intervention group and 123 to a comparison health and wellness intervention group. A 12-week individually tailored, motivationally matched program designed to increase the compliance with guidelines for exercise during pregnancy (30 min/day). The GWG and compliance with 2009 Institute of Medicine (IOM) guidelines for GWG abstracted from medical records. Unadjusted logistic regression, intent-to-treat. Results were added to the existing meta-analyses using a random effects model. Women randomized to the exercise group had a lower mean GWG than the comparison group (-0.97 kg, P value = .39) and were less likely to exceed IOM guidelines (odds ratio = 0.69, 95% confidence interval [CI] 0.34-1.40), but results were not statistically significant. Meta-analyses yielded a -0.63 kg (95% CI -1.17 to -0.08, P = .02) reduction in GWG and a 20% reduction in odds of exceeding IOM guidelines (95% CI 0.73 to 0.89) for the exercise intervention. Findings from this randomized trial among ethnically diverse women contribute to the results of meta-analyses supporting exercise as a means of attenuating GWG.

Promoting Prenatal Exercise From a Sociocultural and Life-Course Perspective: An “Embodied” Conceptual Framework

ABSTRACTPurpose: Prenatal exercise is a health behavior that is receiving growing attention amid concern that women in Western societies are gaining excess weight during pregnancy and contributing to future obesity in both the mother and child. In this article, we draw on insights from the fields of social epidemiology and social theory of the body to examine existing prenatal exercise interventions and to propose a multidimensional framework intended to guide future theorizing and intervention design. Method: A scoping review of existing prenatal exercise programs and interventions focused on controlling gestational weight gain was conducted. Articles published prior to January 2017 were obtained from PubMed and CINAHL, and relevant articles were identified (n = 62) using specified inclusion and exclusion criteria. Identified articles were further analyzed to classify the level(s) of the socioecological model targeted in the intervention or program. Results: The majority of existing interventions target intrapersonal factors during pregnancy and do not attend to the role that cumulative exposure of social and structural disadvantage over the lifetime—not just during the prenatal period—plays in shaping health outcomes. In response, a multidimensional framework is proposed that includes key concepts that facilitate a life-course perspective, as well as attention to the integration of biological and social factors as they relate to health and health-related behaviors. Conclusion: Efforts to promote prenatal exercise and to improve maternal and infant health should attend to how systemic inequality impacts women’s health.

Effect of an Exercise Intervention on Gestational Diabetes Mellitus

To examine the effect of an individually tailored, motivationally matched prenatal exercise intervention on gestational diabetes mellitus (GDM) and other measures of glucose intolerance among ethnically diverse prenatal care patients at increased risk for GDM. The Behaviors Affecting Baby and You study randomized eligible women at a mean (standard deviation) of 18.2 (4.1) weeks of gestation to a 12-week individually tailored, motivationally matched exercise intervention or a comparison health and wellness intervention. The goal of the exercise intervention was to achieve the American College of Obstetricians and Gynecologists' guidelines for physical activity during pregnancy. Diagnosis of GDM, impaired glucose tolerance, abnormal glucose screen, and screening glucose values (mg/dL) were abstracted from medical records. A sample size of 352 women (176 per group) was planned to have 80% power to detect reductions in risk of 35% or larger. From July 2007 to December 2012, a total of 251 (86.5%) women completed the intervention; n=124 and 127 in the exercise and comparison interventions, respectively. Based on an intention-to-treat analysis, no statistically significant differences between the intervention groups were observed; the relative odds of GDM in the exercise group was 0.61 (95% confidence interval [CI] 0.28-1.32) as compared with the health and wellness comparison group. Odds ratios for impaired glucose tolerance and abnormal glucose screen were 0.68 (95% CI 0.35-1.34) and 0.86 (95% CI 0.51-1.47), respectively. The intervention had no effect on birth outcomes. In this randomized trial among ethnically diverse pregnant women at increased risk for GDM, we found that a prenatal exercise intervention implemented in the second trimester did not result in a statistically significant reduction in relative odds for GDM, impaired glucose tolerance, or abnormal glucose screen. I.

Influence of Prenatal Exercise on Fetal/Infant Health

Over 30% of children, as young as 6 years, are overweight or obese with increased risk factors of heart disease. Excess adipose, especially abdominal, is associated with increased risk of heart disease. Research has shown an association between obesity, cardiovascular disease, and autonomic imbalance. It has been suggested that a major focus of disease prevention should target the prenatal period, since this is a critical time of organ development. Our previous studies found prenatal exercise is associated with improved fetal, infant, and child heart health and autonomic control. Though these results are promising, exercise was self‐reported and subject to bias. Therefore we conducted a preliminary exercise intervention study with the goal to test the hypothesis that prenatal exercise intervention will improve fetal and infant measures of heart rate (HR), obesity, and nervous system development. Participants either exercised (5+45 min,3X per wk,16‐36 wks pregnant) or did not. Statistical analyses included t‐tests &amp; ANOVA. Preliminary data show lower HR and adipose accumulation, with increased HR variability and neurodevelopmental scores in fetus and infants of exercisers compared to offspring of controls. This study is of public import regarding prevention of heart disease and obesity by targeting the critical time period before birth in order to improve child health, potentially decrease health care costs, while being a safe, low‐cost, non‐pharmacologic intervention available to the general public.

The Power of Believing: Salient Belief Predictors of Exercise Behavior in Normal Weight, Overweight, and Obese Pregnant Women.

Nearly 50% of U.S. women enter pregnancy as overweight or obese (OW/OB). There is a critical need to understand how to motivate OW/OB pregnant women for exercise behavior to improve their health and reduce adverse pregnancy outcomes. To examine salient Theory of Planned Behavior belief predictors of normal weight (NW) and OW/OB pregnant women's exercise behavior (EXB) across pregnancy. Pregnant women (N = 357) self-reported their exercise beliefs and behavior during each pregnancy trimester. Pearson correlations were used to examine exercise beliefs-behavior associations. Stepwise regressions were used to identify trimester (TRI) 1 and TRI 2 belief predictors of TRI 2 and TRI 3 EXB, respectively, for each weight status group. Belief endorsement was examined to identify critical beliefs. TRI 1 EXB beliefs explained 58% of the total variance (22% NW, 36% OW/OB) in TRI 2 EXB. TRI 2 EXB beliefs explained 32% of the total variance (17% NW, 15% OW/OB) in TRI 3 EXB. Individual beliefs varied by weight status and trimester. Control beliefs emerged with the lowest endorsement; making them most critical to target for exercise interventions. Prenatal exercise interventions should be weight status specific and target salient beliefs/barriers unique to the pregnancy trimesters.

Impact of an exercise intervention on physical activity during pregnancy: the behaviors affecting baby and you study.

We examined the impact of a prenatal exercise intervention on physical activity in 260 women at risk for gestational diabetes mellitus. We randomized participants in the Behaviors Affecting Baby and You (BABY) Study, which took place from 2007 to 2012, to either a 12-week individually tailored, motivationally matched exercise intervention (n=132) or to a comparison health and wellness intervention (n=128). We assessed physical activity with the Pregnancy Physical Activity Questionnaire. We used linear mixed models to evaluate the impact of the interventions on change in physical activity according to intensity and type, total walking, and sedentary behavior. Compared with the health and wellness arm, the exercise arm had significantly greater increases in sports or exercise activity (0.3 vs 5.3 metabolic equivalent of task [MET] hours/week; P<.001), and smaller declines in total activity (-42.7 vs -2.1 MET hours/week; P=.02) and activities of moderate to vigorous intensity (-30.6 vs -10.6 MET hours/week; P=.05), and was more likely to achieve recommended guidelines for physical activity (odds ratio=2.12; 95% confidence interval=1.45, 3.10). These findings extend the previous literature by demonstrating the benefits of a clinically feasible exercise intervention in an ethnically and socio-economically diverse population. Given the increased risk of adverse maternal health outcomes in ethnic minority groups, these findings may have important implications for reducing health disparities.