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Purpose: Healthy pregnancy is typically associated with favorable vascular adaptations to both structure and function of the peripheral arteries. Exercise is independently associated with improvements in peripheral vascular health; however, the impact of exercise on prenatal adaptations is unclear. Therefore, we hypothesized that a structured aerobic exercise intervention between the second and third trimesters (TM2 and TM3, respectively) of pregnancy would augment the already-positive changes in vascular outcomes., Methods: We recruited 59 inactive pregnant women (<20 wk of gestation) and randomized them into control (standard care; n = 28) or exercise (moderate-intensity aerobic exercise, 3-4 d·wk-1, 25-40 min, 14 ± 1 wk; n = 31) conditions. Before and after the intervention, all women completed the comprehensive peripheral vascular assessment, which included blood markers of vascular health, carotid distensibility metrics, measures of arterial stiffness (pulse wave velocity), and [superficial] femoral artery reactivity during cold pressor test., Results: Carotid artery diameter increased from 6.5 to 6.9 mm (P < 0.001), and strain (%) decreased from 9.9% to 8.4% (P < 0.001). Carotid artery blood flow, compliance and distensibility coefficients, stiffness (β), distensibility (1/β), and elastic modulus were not different across gestation. Pulse wave velocity was not different across gestation. Superficial femoral artery diameter was increased from 5.4 to 5.6 mm (P = 0.004), whereas blood flow, conductance, and resistance at rest and during the cold pressor test were not different across gestation. None of our measures of vascular health were impacted by exercise., Conclusions: We did not observe an impact of aerobic exercise on altering the changes across pregnancy in blood vessel health. However, the present study was conducted in women who were overall at low risk for developing gestational hypertension and should be interpreted with caution. Future work in high-risk women is needed., (Copyright © 2021 by the American College of Sports Medicine.)

Purpose: This study aimed to evaluate postpartum maternal health and training outcomes of females who were competing or training as elite athletes before or during pregnancy., Methods: Online databases were searched up to August 26, 2020. Studies of any design and language were eligible if they contained information on the relevant population (postpartum athletes [any period after pregnancy]), exposure (engaged in the highest level of sport immediately before or during pregnancy), comparators (sedentary/active controls), and outcomes: maternal (breastfeeding initiation and duration, postpartum weight retention or loss, bone mineral density, low back or pelvic girdle pain, incontinence [prevalence or severity of stress, urge or mixed urinary incontinence, fecal incontinence], injury, anemia, diastasis recti, breast pain, depression, anxiety) and training (<6 wk time to resume activity, training volume or intensity, performance level)., Results: Eleven studies (n = 482 females, including 372 elite athletes) were included. We identified "very low" certainty evidence demonstrating a higher rate of return to sport before 6 wk postpartum among elite athletes compared with nonelite athletes (n = 145, odds ratio = 6.93, 95% confidence interval = 2.73-17.63, I2 = 11). "Very low" certainty evidence from three studies (n = 179) indicated 14 elite athletes obtained injuries postpartum (7 stress fractures, 9 "running injuries"). "Very low" certainty evidence from five studies (n = 262) reported that 101 (40.5%) elite athletes experienced improved performance postpartum., Conclusion: Compared with controls, "very low" quality evidence suggests that elite athletes return to physical activity early in the postpartum period and may have an increased risk of injury. Additional high-quality evidence is needed to safely guide return to sport of elite athletes in the postpartum period., (Copyright © 2021 by the American College of Sports Medicine.)

Purpose: Exercise guidelines recommend incorporating resistance exercise (RE) into a regular aerobic training program during pregnancy. However, few women do so because of uncertainties about the safety of prenatal RE, particularly regarding the Valsalva maneuver (VM). The aim of this study was to determine the acute cardiovascular responses to prenatal RE at different intensities, with and without VM., Methods: Healthy pregnant (n = 15; 22.9 ± 5.9 wk of gestation) and nonpregnant women (n = 15) were recruited. Maximal strength over 10 repetitions (10RM) for semireclined leg press was determined. Women underwent standardized assessments of cardiac structure, function and mechanics (echocardiography), heart rate (ECG), and blood pressure (photoplethysmography) at baseline, during RE at 20%, 40%, and 60% 10RM while free-breathing, and at 40% 10RM with VM. Significant differences were identified between subjects at baseline (independent t-tests), between and within subjects during free-breathing RE (general linear model, baseline as a covariate), and between and within subjects for 40% 10RM free-breathing versus VM (mixed-effects model)., Results: Resting cardiac output, heart rate, and stroke volume were greater in pregnant women, without differences in blood pressure, ejection fraction, or cardiac mechanics. During free-breathing RE, pregnant women had a greater ejection fraction compared with nonpregnant women; however, all other hemodynamic variables were not different between groups. Cardiac mechanics during free-breathing RE across all intensities were not different between groups, with the exception that pregnant women had a lower apical circumferential strain that did not affect global cardiac function. No differences were observed between groups during 40% 10RM RE with and without VM., Conclusions: Pregnant women have proportionate cardiac responses to light-moderate RE, both with and without the VM. These findings reinforce the safety of RE in healthy pregnancy., (Copyright © 2020 by the American College of Sports Medicine.)

Purpose: Women who develop gestational hypertension have evidence of elevated muscle sympathetic nerve activity (MSNA) in early pregnancy, which continues to rise after diagnosis. Exercise has been shown to play a preventative role in the development of gestational hypertension and has been shown to reduce resting and reflex MSNA in nonpregnant populations. We sought to investigate whether aerobic exercise affected the sympathetic regulation of blood pressure between the second and third trimesters of pregnancy., Methods: We conducted a randomized controlled trial of structured aerobic exercise (n = 31) compared with no intervention (control, n = 28) beginning at 16-20 wk and continuing until 34-36 wk of gestation (NCT02948439). Women in the exercise group were prescribed aerobic activity at 50%-70% of their heart rate reserve, on 3-4 d·wk-1 for 25-40 min with a 5-min warm-up and 5-min cool-down (i.e., up to 160 min total activity per week). At preintervention and postintervention assessments, data from ~10 min of quiet rest and a 3-min cold pressor test were analyzed to determine sympathetic nervous system activity and reactivity., Results: MSNA was obtained in 51% of assessments. Resting MSNA burst frequency and burst incidence increased across gestation (main effect of gestational age, P = 0.002). Neurovascular transduction was blunted in the control group (P = 0.024) but not in exercisers (P = 0.873) at the postintervention time point. Lastly, MSNA reactivity during the cold pressor test was not affected by gestational age or exercise (P = 0.790, interaction)., Conclusions: These data show that exercise attenuates both the rise in MSNA and the blunting of neurovascular transduction. This may partially explain the lower risk of developing gestational hypertension in women who are active during their pregnancies., (Copyright © 2020 by the American College of Sports Medicine.)

Purpose: The purpose of this systematic review was to evaluate fetal and maternal pregnancy outcomes of elite athletes who had participated in competitive sport immediately before conception., Methods: Online databases were searched up to March 24, 2020. Studies of any design and language were eligible if they contained information on the relevant population (pregnant women), exposure (engaged in elite sport immediately before pregnancy), and outcomes (birth weight, low birth weight, macrosomia, preterm birth, fetal heart rate and pulse index, cesarean sections, instrumental deliveries, episiotomies, duration of labor, perineal tears, pregnancy-induced low back pain, pelvic girdle pain, urinary incontinence, miscarriages, prenatal weight gain, inadequate/excess prenatal weight gain, maternal depression or anxiety)., Results: Eleven unique studies (n = 2256 women) were included. We identified "low" certainty evidence demonstrating lower rates of low back pain in elite athletes compared with active/sedentary controls (n = 248; odds ratio, 0.38; 95% confidence interval, 0.20-0.73; I2 = 0%) and "very low" certainty evidence indicating an increased odds of excessive prenatal weight gain in elite athletes versus active/sedentary controls (n = 1763; odds ratio, 2.47; 95% confidence interval, 1.26-4.85; I2 = 0%). Low certainty evidence from two studies (n = 7) indicated three episodes of fetal bradycardia after high-intensity exercise that resolved within 10 min of cessation of activity. No studies reported inadequate gestational weight gain or maternal depression or anxiety. There were no differences between elite athletes and controls for all other outcomes., Conclusions: There is "low" certainty of evidence that elite athletes have reduced odds of experiencing pregnancy-related low back pain and "very low"certainty of evidence that elite athletes have increased the odds of excessive weight gain compared with active/sedentary controls. More research is needed to provide strong evidence of how elite competitive sport before pregnancy affects maternal and fetal outcomes.PROSPERO Registration: CRD42020167382., (Copyright © 2020 by the American College of Sports Medicine.)

Purpose: This study aimed to examine the influence of prenatal exercise on maternal cardiorespiratory health and fitness during pregnancy., Methods: 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)., Results: 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%)., Conclusion: 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.

Purpose: To determine the role of moderate-to-vigorous physical activity (MVPA) and sedentary behavior in flow-mediated dilation (FMD) and glucose metabolism during late pregnancy., Methods: Seventy normotensive, euglycemic pregnant women (31.6 ± 2.9 yr) in their third trimester (28-39 wk) were recruited. After a fasted blood sample; FMD was measured (brachial artery Doppler ultrasonography, normalized for the shear stimulus [area under the curve]). Anterograde and retrograde shear rate were estimated. Physical activity (MVPA) and sedentary behavior were assessed via accelerometry for seven consecutive days (Actigraph wGT3X-BT). We categorized the women as active (>150 min·wk) or inactive (<150 min·wk) according to their accelerometry data. Data were corrected for age and gestational age., Results: On average, women were sedentary 67.1% ± 8.2% of their waking hours. Active pregnant women (>150 min·wk MVPA, n = 32) engaged in 266.7 ± 99.3 min·wk MVPA, whereas inactive pregnant women (<150 min·wk MVPA, n = 38) engaged in 76.1 ± 42.5 min·wk MVPA. The FMD response (normalized to the magnitude of shear stress stimulus) was greater in active compared with inactive pregnant women (6.5 ± 4.4 a.u. vs 3.9 ± 3.5 a.u.; F = 4.619; P = 0.005). The MVPA in active pregnant women was inversely correlated with insulin concentrations (r = -0.556; P = 0.03). In inactive pregnant women, higher amounts of sedentary behavior were associated with lower amounts of retrograde shear rate (r = 0.504; P = 0.02), retrograde blood flow (r = 0.499; P = 0.02), and retrograde velocity (r = 0.508; P = 0.02) during baseline, but not correlated with the FMD response., Conclusions: Engaging in MVPA during pregnancy is associated with improved FMD and a lower insulin concentration. Sedentary behavior was not associated with FMD responses.

Purpose: This study aimed to evaluate the effect of an exercise program of two different intensities, with nutritional control, on gestational weight gain (GWG), infant birth weight, and maternal weight retention at 2 months postpartum (2 mopp)., Methods: Pregnant women (prepregnancy body mass index = 18.5-24.9 kg·m) were randomized at study entry (16-20 wk of gestation) to a low-intensity (LI, 30% HR reserve (HRR), n = 23) or moderate-intensity (MI, 70% HRR, n = 26) exercise program, with nutritional control. The exercise program consisted of walking sessions three to four times per week, gradually increasing exercise time from 25 to 40 min per session. Forty-five normal-weight women who did not participate in any structured exercise program during pregnancy and had singleton births were used as a historical control group., Results: Total GWG was higher in the control group (18.3 ± 5.3 kg) compared with the LI (15.3 ± 2.9 kg, P = 0.01) and MI (14.9 ± 3.8 kg, P = 0.003) groups. During the intervention, GWG was similar in both intervention groups, with weekly rates of weight gain of 0.49 ± 0.1 and 0.47 ± 0.1 kg·wk in the LI and MI groups, respectively. Excessive GWG during the intervention was prevented in 70% of the women in the LI group and 77% of those in the MI group. Excessive GWG occurred before the intervention began. At 2 mopp, 18% and 28% of the women in the LI and MI groups, respectively, retained ≤2.0 kg compared with only 7% of those in the control group. Infant birth weight was not different between the groups., Conclusions: Results suggest that a prenatal nutrition and exercise program regardless of exercise intensity, reduced excessive GWG and decreased weight retention at 2 mopp in women of normal weight before pregnancy.

Purpose: Women who are unable to return to a healthy weight by 6 months postpartum increase their risk factors for the development of chronic disease (CD; including metabolic syndrome, obesity, and cardiovascular disease). In a prospective randomized intervention study, we examined the effect of exercise intensity on risk factors for CD in the postpartum. We hypothesized that women receiving an intervention targeting healthy weight loss would have improved CD risk factors compared with women not receiving the intervention. Further, we hypothesized that nutrition control and moderate-intensity exercise would have the greatest improvement in CD risk factors versus low-intensity exercise., Methods: Women were randomly assigned to a nutrition plus low-intensity (30% HR reserve; n = 20) or moderate-intensity (70% HR reserve; n = 20) exercise intervention group. The program consisted of supervised walking for 45 min, three to four times per week for 16 wk. All women were screened for CD at the beginning (7-8 wk postpartum) and at the end (23-25 wk postpartum) of the study. A historical control group of 20 sedentary postpartum women was matched by body mass index, age, and parity., Results: The low- and moderate-intensity groups lost more body mass (-4.2 ± 4.0 and -5.0 ± 2.9 kg, respectively) compared with the control group (-0.1 ± 3.3 kg, P < 0.01). Plasma low-density lipoprotein was reduced for the low- and moderate-intensity groups (-0.29 ± 0.21 and -0.28 ± 0.17 mmol · L) compared with the control group (0.03 ± 0.18 mmol · L, P = 0.015). In addition, glucose concentrations were reduced and adiponectin concentrations increased (P = 0.037), regardless of exercise intensity, although the sedentary controls remained unchanged or at increased risk for CD., Conclusions: Women receiving a postpartum intervention targeting healthy weight loss, regardless of exercise intensity, improved CD risk factors compared with women not receiving the intervention.