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Studies have reported enhanced thermoregulatory function as pregnancy progresses; however, it is unclear if differences in thermoregulation are attributed to weight gain or other physiological changes. This study aimed to determine if total body weight will influence thermoregulation (heat production (H prod )), heart rate, and perceptual measurements in response to weight-bearing exercise during early to late pregnancy. A cross-sectional design of healthy pregnant women at different pregnancy time points (early, T1; middle, T2; late, T3) performed a 7-stage weight-bearing incremental exercise protocol. Measurements of H prod , HR, and RPE were examined. Two experimental groups were studied: (1) weight matched and (2) non-weight matched, in T1, T2, and T3. During exercise, equivalent H prod at T1 (326 ± 88 kJ), T2 (330 ± 43 kJ), and T3 (352 ± 52 kJ) (p = 0.504); HR (p = 0.830); and RPE (p = 0.195) were observed in the WM group at each time point. In the NWM group, H prod (from stages 1-6 of the exercise) increased across pregnancy time points, T1 (291 ± 76 kJ) to T2 (347 ± 41 kJ) and T3 (385 ± 47 kJ) (p < 0.001). HR increased from T1 to T3 in the warm-up to stage 6 (p = 0.009). RPE did not change as pregnancy time point progressed (p = 0.309). Total body weight, irrespective of pregnancy time point, modulates H prod and HR during exercise. Therefore, accounting for total body weight is crucial when comparing thermoregulatory function during exercise across pregnancy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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.

Background: Physical literacy-focused afterschool activity programs (ASAPs) can be an effective strategy to improve children's health-related parameters. We sought to compare physical activity, body composition, aerobic capacity, and fundamental movement skills between physical literacy-focused ASAP and a standard recreational ASAP., Method: A pre-post (6 months) comparison study was conducted in 5- to 12-year-old children in a physical literacy-focused ASAP (physical literacy group, n = 14) and children attending a standard recreational ASAP (comparison group, n = 15). Physical activity guideline adherence was assessed using accelerometry, body composition was analyzed using bioelectrical impedance, aerobic capacity was estimated using the Progressive Aerobic Cardiovascular Endurance Run test, and fundamental movement skills were evaluated using the Test of Gross Motor Development-2., Results: There were no significant differences between groups at baseline. After 6 months, the physical literacy group exhibited a significant improvement in their total raw score for the Test of Gross Motor Development-2 ( p = .016), which was likely due to improvements in object control skills ( p = .024). The comparison group significantly increased body mass index ( p = .001) and body fat ( p = .009) over time. No significant between-group differences were found; however, there was a trend for improved aerobic capacity in the physical literacy group ( d = 0.58)., Conclusions: Engagement in the physical literacy-focused ASAP contributed to an attenuated increase in adiposity and an improvement in object control skills.

Introduction: Adherence to physical activity (PA) and gestational weight gain (GWG) recommendations during pregnancy has been shown to improve maternal and fetal health outcomes, including reducing the risk for chronic diseases. Limited research has evaluated the effect of meeting PA in combination with GWG recommendations on placental efficiency (Pl-E), a surrogate marker of the placenta's ability to exchange nutrients and gas based on surface area. The purpose of this study was to measure and compare Pl-E based on meeting PA and GWG recommendations., Method: Healthy pregnant women (n = 61) wore accelerometers in their second and third trimesters to objectively measure PA. Women were classified as active or inactive at each time point based on meeting the 2019 Canadian prenatal PA guidelines. Total GWG was calculated as weight measured in the third trimester minus self-reported prepregnancy weight, and were categorized as insufficient (n = 19), adequate (n = 22), and excessive (n = 20) according to the 2009 Institute of Medicine guidelines. Placental weight (PW) and birth weight (BW) were measured within 30 min of delivery and 24-48 h postdelivery, respectively. Pl-E was determined in three ways: BW:PW ratio, residual BW, and measured BW, with a higher value indicating better Pl-E. Pl-E was compared by PA and GWG status using a two-way ANOVA., Results: No differences were found in the BW:PW ratio or residual BW corresponding to PA and GWG status. Measured BW was significantly higher in newborns of women who gained weight excessively compared with those who gained insufficient weight (P < 0.05)., Conclusion: These findings suggest that prenatal PA does not compromise Pl-E; however, further research is required to evaluate the potential mechanistic benefits of meeting PA and GWG guidelines on the placenta., (Copyright © 2020 by the American College of Sports Medicine.)

Background: The authors examined whether or not ≤3 days wearing Actical® accelerometers provided acceptable results in comparison with the recommendation of ≥4 days in women across gestation., Methods: A total of 26, 76, and 57 participants at early, mid, and late pregnancy, respectively, were assessed. Participants were instructed to wear the device for 7 days and women who wore it for ≥4 days were included. For each participant, 3, 2, and 1 day(s) were randomly selected. Paired comparisons, intraclass correlations coefficients, and kappa statistics were performed for ≥4 days (criterion) versus 3, 2, and 1 day(s). Averages (in minutes per day) of sedentary time, light, moderate, vigorous, moderate to vigorous physical activity (PA) and steps per day were examined., Results: When 3 valid days were compared with the criterion, no significant differences were found for any gestational period. The intraclass correlations coefficients were "high" for all PA-related variables. The k values varied from .819 to .838 across pregnancy ("strong"). Two and 1 valid day(s) versus the criterion showed significant differences in some PA intensities, reduced intraclass correlations coefficients, "moderate" k values for 2 valid days (.638-.788) and "minimal-to-moderate" k values for 1 valid day (.367-.755)., Conclusion: In pregnant women during early, mid, and late pregnancy, PA data obtained from 3 valid days of wear was equivalent and agreed with ≥4 valid days.

Purpose: Limited research has measured the effect of physical activity (PA) interventions on health-related quality of life (HRQoL) among pre-school-aged children. This study evaluates the effect of the Activity Begins in Childhood (ABC) cluster-randomized controlled trial designed to increase PA in the ages 3-5 years on HRQoL., Methods: This was a cluster-randomized controlled trial where the intervention group included PA education delivered to daycare providers only, or daycare providers and parents. In the current study, the two PA intervention groups were combined. The comparator group received standard daycare curriculum (COM). A total of 215 children were included (PA n = 161, COM n = 54). Parents completed the proxy Pediatric Quality of Life Inventory Generic Core Scale (PedsQL™ 4.0) to measure HRQoL at baseline and the end of the 6-month trial. HRQoL scores were analyzed as physical, psychosocial, and total domains. Baseline and 6-months measurements were compared for PA and COM groups, and mean changes in scores (95% confidence intervals) were measured using absolute values., Results: No between-group differences were observed for the physical (p = 0.17), psychosocial (p = 0.95) or total scores (p = 0.20). Paired comparisons showed that only the PA group improved psychosocial- (PA mean difference = 2.18 (0.20, 4.15), p = 0.03; COM mean difference = 2.05 (- 1.03, 5.13), p = 0.19) and total-HRQoL scores (PA mean difference = 2.83 (1.83, 3.84), p < 0.001; COM mean difference = 0.19 (- 1.78, 2.16), p = 0.84) after 6 months., Conclusion: Although the within-PA group analysis showed an improvement in psychosocial and total HRQoL scores from baseline, no between-group differences were observed in the HRQoL over time among children aged 3-5 years.

Background: Research on sedentary behavior and effects on maternal and newborn outcomes has been inconclusive. The objective of this report was to correlate sedentary time with maternal and fetal anthropometric measurements and compare the effect on sedentary time based on meeting prenatal activity guidelines., Methods: Healthy pregnant women (N = 61) in their second trimester (24-28 wk gestation) provided 7-day accelerometry data. Outcomes, including neonatal weight, length, and body fat percentage, were collected 24 to 48 hours after delivery. Placenta weight was measured immediately after delivery. Gestational weight gain was calculated by subtracting self-reported prepregnancy weight from measured weight at 38 weeks gestation. Correlations between sedentary time and outcomes were tested with Spearman and Pearson coefficient of correlations in all women separately and in accordance with the 2019 Canadian prenatal exercise guidelines., Results: No significant associations were found between sedentary time and the selected outcomes, even when compared by prenatal exercise level. There was no difference in total time spent sedentary between active (576.7 [52.8] min) and inactive women (599.3 [51.6] min)., Conclusions: Meeting exercise recommendations during pregnancy does not significantly decrease total sedentary time. Future studies should aim to evaluate the health effects of both decreasing sedentary time and meeting prenatal exercise guidelines.

Pregnant women are recommended to engage in 150 min of moderate-intensity physical activity per week to reduce pregnancy complications. Many women struggle to remain physically active throughout pregnancy, and there is no consensus about whether women adopt a less efficient movement pattern as they progress through pregnancy and experience gestational weight gain. This study assessed the change in energy expenditure and mechanical efficiency in pregnant women (PREG; n = 10) when performing a walking treadmill task in early, mid, and late pregnancy and also compared with an age- and body mass index-matched, nonpregnant (CON; n = 10) group. On average, the PREG group gained within the Institute of Medicine's gestational weight gain guidelines (11.6 ± 3.6 kg) and were all inactive (measured using accelerometry), except for 1 participant, by the third trimester, as per the 2019 Canadian physical activity guidelines for pregnant women. Energy expended to complete the walking task increased throughout pregnancy and was higher than the controls (111.5 ± 24.6 kcal) in mid and late pregnancy (139.0 ± 22.2 kcal, p = 0.02, and 147.3 ± 24.6 kcal, p = 0.005, respectively), but not early pregnancy (129.9 ± 18.9 kcal, p = 0.08). Walking mechanical efficiency was similar within pregnant women at each time point and compared to nonpregnant controls. Our findings add to the growing body of evidence demonstrating that pregnant women can safely perform physical activity by showing that walking mechanical efficiency is unchanged at low to moderate intensities. Novelty Energy demand during exercise increases proportionally to weight gain across pregnancy trimesters. However, mechanical efficiency remains unchanged during low- to moderate-intensity walking.

To compare water- versus land-based exercise programs, as part of a multidisciplinary intervention, on physical fitness and health-related quality of life in overweight and obese adolescents. A total of 151 overweight and obese adolescents (age: 13.2±1.8years) were divided into: 1) a water-based intervention (WB; n=28); 2) a land-based intervention (LB; n=57); and 3) a control group (CG; n=66). Anthropometric measures, body composition, flexibility, abdominal strength/endurance, cardiorespiratory fitness and health-related quality of life were assessed prior and by the end of a 16-week intervention. Both the water- and land-based interventions were part of a multidisciplinary program focusing on behavioral changes. Fat Mass (%) was significantly reduced in both intervention groups and a higher progression was observed in the WB group (-9.8±7.2% versus -6.1±6.2%; p<0.05 for pre-to-post changes within-groups). However, LB increased more abdominal strength than WB (69.6±165.8% versus 53.4±83.4%; p<0.05) and significantly increased social (19.7±88.8%), psychosocial (5.1±15.1%) and total score (6.3±14.8%), which was observed in neither WB nor CG. The intervention groups did not change body weight (WB: -1.7±5.3%; LB: 0.1±3.4%; p>0.05 for both groups) and increased (p<0.05) fat-free mass (WB: 4.6±4.0%; LB: 4.4±4.1%), VO2max (WB: 9.3±7.8%; LB: 11.0±13.4%), and physical dimension of quality of life (WB: 9.2±17.2%; LB: 8.9±18.0%) differently of what was observed in CG. The physical dimension improvement observed in the land-based and water-based samples was associated with decreased percentage fat mass (r=0.282 and 0.229; p<0.05). We suggest water- and land-based physical exercises within a multidisciplinary program promote similar improvements in body composition, physical fitness and health-related quality of life in overweight and obese adolescents., (Copyright © 2016. Published by Elsevier Inc.)

The aim of this study was to investigate the association between cardiac parasympathetic activity and cardiorespiratory fitness, insulin, and hemodynamic profile in overweight and obese adolescent girls and boys (aged 12-16 years). Data were taken from the Multidisciplinary Obesity Treatment Program. Only post-intervention measurements are presented herein. Body composition, cardiorespiratory fitness, blood pressure, and metabolic profile (insulin and glucose profile) of adolescents were assessed. Cardiac parasympathetic activity was determined by resting heart rate variability, which was analyzed using a heart rate monitor. Greater parasympathetic cardiac activity was associated with higher levels of cardiorespiratory fitness in both girls and boys (0.375 ≤ r ≤ 0.900), while the sympathetic-vagal balance was negatively related to maximal oxygen uptake (VO2max) in girls (r = 0.478). An association between lower parasympathetic activity and insulin resistance was noted in girls (mean of R-R intervals [RRmean] and homeostasis model assessment insulin-resistance index [HOMA-IR]: r = -0.678), while greater systolic blood pressure (SBP) and lower parasympathetic activity were associated in both sexes (RRmean and SBP: r = -0.526; high frequency [HF (nu)] and SBP: r = -0.754). In conclusion, autonomic nervous system activity was associated with cardiorespiratory fitness, insulin resistance, and SBP in overweight and obese adolescents. The identification of these potential relationships assists with the establishment of future long-term exercise interventions that evaluate the improvements in parasympathetic nervous system activity, in addition to metabolic profile and cardiorespiratory fitness in overweight and obese adolescents.

Objectives: This study compared the responses during maximal incremental treadmill tests of 1-min, 2-min, and 3-min stage durations mainly in terms of maximal heart rate (HRmax) and peak blood lactate concentration (LApeak)., Design: Repeated-measures., Methods: Thirty-four male, recreational, endurance-trained runners (40±13 years) performed three tests on a motorized treadmill. The tests started at 8kmh(-1) with increments of 1kmh(-1) every 1min for the short-stage protocol, every 2min for the intermediate-stage protocol, and every 3min for the long-stage protocol. LApeak was defined for each subject as the highest value among the lactate concentrations determined at the end of each test and at the third, fifth and seventh minutes after test, during passive recovery., Results: Analysis of variance revealed a significant effect of the stage duration on the HRmax (p=0.003) and LApeak (p=0.001). The HRmax was higher in the intermediate-stage compared to the short-stage protocol (184.8±12.7 vs. 181.8±12.1beatsmin(-1), p<0.001), but no significant differences were found between the long-stage (183.1±12.1beatsmin(-1)) and the intermediate-stage or short-stage protocols (p>0.05). The LApeak was lower in the long-stage compared to the short-stage and intermediate-stage protocols (7.9±2.2 vs. 9.4±2.2 and 9.2±1.9mmolL(-1), respectively, p<0.05). Further, blood lactate reached peak concentration at the fifth minute after test for all the protocols., Conclusions: Thus, HRmax and LApeak depend on the stage duration of the incremental test, but the moment at which blood lactate reaches peak concentration is independent of the duration. Further, we suggest 2-min stage duration protocols to determine HRmax., (Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)