Sex differences in 3- to 5-year-old children's motor competence: A pooled cross-sectional analysis of 6241 children.

There is some, albeit inconsistent, evidence supporting sex differences in preschoolers' motor competence (MC), with these observations not uniform when analyzed by age, and cultural groups. Thus, this study examined sex differences across ages in 3- to 5-year-old children's MC. A cross-country pooled sample of 6241 children aged 3-5 years (49.6% girls) was assessed for MC using the Test of Gross Motor Development-2nd/3rd edition, and children were categorized into groups of age in months. Multiple linear regression models and predictive margins were calculated to explore how sex and age in months affect scores of MC (i.e., locomotor and ball skills), with adjustments for country and BMI. The Chow's Test was used to test for the presence of a structural break in the data. Significant differences in favor of girls were seen at 57-59 and 66-68 months of age for locomotor skills; boys performed better in ball skills in all age periods, except for 42-44 and 45-47 months of age. The higher marginal effects were observed for the period between 45-47 and 48-50 months for locomotor skills (F = 30.21; and F = 25.90 for girls and boys, respectively), and ball skills (F = 19.01; and F = 42.11 for girls and boys, respectively). A significantly positive break point was seen at 45-47 months, highlighting the age interval where children's MC drastically improved. The identification of this breakpoint provides an evidence-based metric for when we might expect MC to rapidly increase, and an indicator of early delay when change does not occur at that age.

Association between walking speed and calcaneus stiffness index in older adults.

INTRODUCTION: The aim here is to examine the association between objectively measured usual walking speed (UWS) and bone status in community-dwelling older Chinese. MATERIALS AND METHODS: This is a cross-sectional study of a population of 1528 adults (817 females, mean age 68.5 ± 5.3; 711 males, mean age 69.1 ± 5.2) aged 60-79, living in communities in Shanghai. Walking speed was assessed using a 4-m walk test at a usual-pace walking speed a walking speed at which the subject felt relaxed-and bone status measured by quantitative ultrasound (QUS). The health-related characteristics of participants include family background, physical activity level, chronic disease, smoking and alcohol consumption, frequency of falls, vitamin intake, and hormone therapy. RESULTS: Multiple linear regression is used to analyses any association between UWS and bone status, adjusting for confounding factors showing a significant association between faster UWS and a higher calcaneal stiffness index (SI) (p < 0.01). Comparing the lowest quartile of the data set with the highest at UWS, a high SI is achieved with 5.34 (95% CI = 3.22, 7.46) (p < 0.01), after adjusting for confounders. An increase of 1 dm/s was associated with a 0.91 (95% CI = 0.53, 1.29) increase in SI. This relationship for most subgroups is consistent. CONCLUSION: Our findings suggest that UWS can be a sensitive indicator of calcaneal bone loss among an older population.

The association between the health-related physical fitness and inhibitory control in preschool children.

BACKGROUND: Inhibitory control develops rapidly during the preschool stage, and development of inhibitory control in this period is significant for the healthy growth of the future. However, most studies paid more attention to children and adolescents in recent years, but less focus on preschool children. Therefore, the purpose of this study was to explore the association between the health-related physical fitness and inhibitory control in preschool children. METHODS: This cross-sectional study was based on a baseline data from randomized controlled trial by cluster sampling(including 128 preschoolers, 70 boys, 58girls).The health-related physical fitness T-score (HPFT) was obtained by adding standard scores of six indicators: body mass index, handgrip strength, standing long jump, one-leg balance, 2 × 10 m shuttle run test, and 20 m shuttle run test. Inhibitory control was assessed using the flanker task and reflected by reaction time and accuracy. RESULTS: A total of 120 preschoolers were included in the final statistical analysis. After adjusting the confounders, HPFT was associated with reaction time (ß=-2.49 ms, 95%CI: -4.22, -0.75). Similarly, a negative association was observed between one-leg balance and reaction time (ß=-12.04 ms, 95%CI: -18.94, -5.15), and between 20 m shuttle run test and reaction time (ß=-23.28 ms, 95%CI: -37.00, -9.56). Compared with the participants in the lowest tertile, HPFT (ß=-158.74, 95%CI: -309.63, -7.84), one-leg balance (ß=-267.25 ms, 95%CI: -420.71, -113.79) and 20 m shuttle run test (ß=-215.58 ms, 95%CI: -374.67, -56.49) were all negatively associated with reaction time of those in the highest tertile. CONCLUSIONS: Negative relationships between HPFT and RT of the inhibitory control were observed in preschoolers. To have better inhibitory control, it's suggested that HPFT of preschoolers should be at least 249. These findings are of great significance for the early improvement of HPFT and the development of inhibitory control in preschool children.

Effects of weight-bearing dance aerobics on lower limb muscle morphology, strength and functional fitness in older women.

Objective: To investigate the effects of 12-week weight-bearing dance aerobics (WBDA) on muscle morphology, strength and functional fitness in older women. Methods: This controlled study recruited 37 female participants (66.31y ± 3.83) and divided them into intervention and control groups according to willingness. The intervention group received 90-min WBDA thrice a week for 12 weeks, while the control group maintained normal activities. The groups were then compared by measuring muscle thickness, fiber length and pennation angle by ultrasound, muscle strength using an isokinetic multi-joint module and functional fitness, such as 2-min step test, 30-s chair stand, chair sit-and-reach, TUG and single-legged closed-eyed standing test. The morphology, strength, and functional fitness were compared using ANCOVA or Mann-Whitney U test to study the effects of 12 weeks WBDA. Results: Among all recruited participants, 33 completed all tests. After 12 weeks, the thickness of the vastus intermedius (F = 17.85, P < 0.01) and quadriceps (F = 15.62, P < 0.01) was significantly increased in the intervention group compared to the control group, along with a significant increase in the torque/weight of the knee flexor muscles (F = 4.47, P = 0.04). Similarly, the intervention group revealed a significant improvement in the single-legged closed-eyed standing test (z = -2.16, P = 0.03) compared to the control group. Conclusion: The study concluded that compared to the non-exercising control group, 12-week WBDA was shown to thicken vastus intermedius, increase muscle strength, and improve physical function in older women. In addition, this study provides a reference exercise program for older women.

2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities.

BACKGROUND: The Compendium of Physical Activities was published in 1993 to improve the comparability of energy expenditure values assigned to self-reported physical activity (PA) across studies. The original version was updated in 2000, and again in 2011, and has been widely used to support PA research, practice, and public health guidelines. METHODS: This 2024 update was tailored for adults 19-59 years of age by removing data from those ≥60 years. Using a systematic review and supplementary searches, we identified new activities and their associated measured metabolic equivalent (MET) values (using indirect calorimetry) published since 2011. We replaced estimated METs with measured values when possible. RESULTS: We screened 32,173 abstracts and 1507 full-text papers and extracted 2356 PA energy expenditure values from 701 papers. We added 303 new PAs and adjusted 176 existing MET values and descriptions to reflect the addition of new data and removal of METs for older adults. We added a Major Heading (Video Games). The 2024 Adult Compendium includes 1114 PAs (912 with measured and 202 with estimated values) across 22 Major Headings. CONCLUSION: This comprehensive update and refinement led to the creation of The 2024 Adult Compendium, which has utility across research, public health, education, and healthcare domains, as well as in the development of consumer health technologies. The new website with the complete lists of PAs and supporting resources is available at https://pacompendium.com.

Older Adult Compendium of Physical Activities: Energy costs of human activities in adults aged 60 and older.

PURPOSE: To describe the development of a Compendium for estimating the energy costs of activities in adults ≥60 years (OA Compendium). METHODS: Physical activities (PAs) and their metabolic equivalent of task (MET) values were obtained from a systematic search of studies published in 4 sport and exercise databases (PubMed, Embase, SPORTDiscus (EBSCOhost), and Scopus) and a review of articles included in the 2011 Adult Compendium that measured PA in older adults. MET values were computed as the oxygen cost (VO2, mL/kg/min) during PA divided by 2.7 mL/kg/min (MET60+) to account for the lower resting metabolic rate in older adults. RESULTS: We identified 68 articles and extracted energy expenditure data on 427 PAs. From these, we derived 99 unique Specific Activity codes with corresponding MET60+ values for older adults. We developed a website to present the OA Compendium MET60+ values: https://pacompendium.com. CONCLUSION: The OA Compendium uses data collected from adults ≥60 years for more accurate estimation of the energy cost of PAs in older adults. It is an accessible resource that will allow researchers, educators, and practitioners to find MET60+ values for older adults for use in PA research and practice.

Effects of 12-week aerobic exercise with different frequencies on executive function in preschool children: a cluster randomized controlled trial.

OBJECTIVE: To explore the effects of a 12-week aerobic exercise program with different frequencies on executive functions (EFs) in preschool children. METHOD: Four kindergartens, comprising 126 preschool children in Shanghai, were enrolled in this 12-week cluster randomized controlled trial with a 12-week follow-up period. Kindergartens were allocated to high-frequency (three times a week) or low-frequency (once a week) exercise groups using stratified block randomization. Three core sub-EFs, including inhibition, working memory, and cognitive flexibility, were assessed at baseline, post-intervention, and the 12-week follow-up. RESULTS: Compared to baseline, both groups showed significant improvements in inhibition and working memory after the intervention and at the 12-week follow-up. However, only the high-frequency exercise group demonstrated a significant improvement in cognitive flexibility after the follow-up period. Nonetheless, there were no significant differences in the core sub-functions of EFs between the two groups at the end of the intervention or the follow-up periods. CONCLUSION: A 12-week aerobic exercise of three times a week was insufficient to significantly improve EFs in preschool children compared to once a week. Future studies are needed to examine the dose-response relationship of aerobic exercise on EFs and to verify the effects of different exercise modalities on EFs in preschool children.

Motor Competence and Body Mass Index in the Preschool Years: A Pooled Cross-Sectional Analysis of 5545 Children from Eight Countries.

BACKGROUND AND OBJECTIVE: One in five preschool children are overweight/obese, and increased weight status over time increases the risks of poorer future health. Motor skill competence may be a protective factor, giving children the ability to participate in health-enhancing physical activity. Yet, we do not know when the relationship between motor competence and weight status first emerges or whether it is evident across the body mass index (BMI) spectrum. This study examined the association between motor skill competence and BMI in a multi-country sample of 5545 preschoolers (54.36 ± 9.15 months of age; 50.5% boys) from eight countries. METHODS: Quantile regression analyses were used to explore the associations between motor skill competence (assessed using the Test of Gross Motor Development, Second/Third Edition) and quantiles of BMI (15th; 50th; 85th; and 97th percentiles), adjusted for sex, age in months, and country. RESULTS: Negative associations of locomotor skills, ball skills, and overall motor skill competence with BMI percentiles (p < 0.005) were seen, which became stronger at the higher end of the BMI distribution (97th percentile). Regardless of sex, for each raw score point increase in locomotor skills, ball skills, and overall motor skill competence scores, BMI is reduced by 8.9%, 6.8%, and 5.1%, respectively, for those preschoolers at the 97th BMI percentile onwards. CONCLUSIONS: Public health policies should position motor skill competence as critical for children's obesity prevention from early childhood onwards. Robust longitudinal and experimental designs are encouraged to explore a possible causal pathway between motor skill competence and BMI from early childhood.

Chronic Exercise for Core Symptoms and Executive Functions in ADHD: A Meta-analysis.

BACKGROUND AND OBJECTIVES: The effects of chronic exercise interventions (CEIs) on core symptoms and executive functions (EFs) of attention-deficit/hyperactivity disorder (ADHD) and how different characteristics of CEIs could modify the effect remain unclear. We synthesized the current evidence on the effects of CEIs on core symptoms and EFs in children and adolescents with ADHD. METHODS: Data sources include PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure from database inception to July 31, 2022. Study selection includes randomized controlled trials that reported on the effects of CEIs on core symptoms and/or EFs in ADHD aged 6 to 18 years. RESULTS: Twenty-two randomized controlled trials were included. CEIs had a small beneficial effect on overall core symptoms (standardized mean difference [SMD] = -0.39, 95% confidence interval [CI]: -0.64 to -0.14), as well as inattention (SMD = -0.32, 95% CI: -0.63 to -0.004) among children and adolescents with ADHD. Closed-skill exercise showed a large improvement in core symptoms (SMD = -0.83, 95% CI: -1.30 to -0.35), whereas open-skill exercise did not. Additionally, CEIs had a moderately beneficial effect on overall EFs (SMD = -0.68, 95% CI: -0.91 to -0.45) and a moderate-to-large effect on the specific domains of EFs. The pooled effects on overall core symptoms and EFs were not significantly modified by study population (children or adolescents), exercise session duration (≤50 or >50 minutes per session, median), or total exercise sessions (<24 or ≥24 sessions, median). CONCLUSIONS: CEIs have small-to-moderate beneficial effects on overall core symptoms and EFs in children and adolescents with ADHD.

Energy Costs of Chair Sitting and Standing Video Exercises in Chinese Older Adults Over 60 Years.

Home-based video exercise interventions improve older adults' physiological performance and functional capacity. Little is known about the energy costs of video exercises in older adults. The Compendium of Physical Activities (PAs) has few items with PA metabolic equivalents (METs) in older adults. This study measured the energy costs of four chair and two standing exercises (sitting Tai Chi, Yoga, mobility ball, aerobics: standing, slow aerobics, and fast aerobics). Fifteen females and 14 males, 62-87 years (M ± SD, 73 ± 7.7 years), were categorized into three age groups (60-69, 70-79, 80-89). Oxygen uptake (VO2, ml·min-1·kg-1) and heart rate (HR, b·min-1) were measured by indirect calorimetry and heart rate monitor. MET values were calculated as standard- (activity VO2/3.5), rounded- (significant digit rounded to 0, 3, 5, 8), and corrected METs (individual resting metabolism). Results showed chair Yoga, Tai Chi, and mobility ball ranged from 2.0 to 2.8 rounded METs (light intensity). Chair- and standing aerobics ranged from 3.0 to 4.3 rounded METs (moderate intensity). Averaged HR ranged from 91.9 ± 12.7 b·min-1 to 115.4 ± 19.1 b·min-1 for all PAs. Corrected METs were higher than standard METs (P < .05). Standard METs were similar between age groups (P > .05). In conclusion, this study is unique as it measures the energy costs of sitting and standing video exercises that can be performed by older adults at home or in an exercise facility. Knowing the energy costs of PAs for older adults can provide exercises interventions to prevent sedentary lifestyles.

Effects of High-Intensity Interval Training and Combined High-Intensity Interval Training Programs on Cancer-Related Fatigue and Cancer Pain: A Systematic Review and Meta-analysis.

PURPOSE: This systematic review and meta-analysis assessed the effectiveness of high-intensity interval training (HIIT) alone and combined HIIT programs compared with usual care on cancer-related fatigue (CRF) and pain related to cancer or cancer-related treatments. METHODS: Articles published prior to January 2023 were searched in the following digital databases: PubMed, Cochrane Database of Systematic Reviews and Cochrane Controlled Clinical Trials (CENTRAL), Web of Science, Scopus and ScienceDirect. Randomized controlled trials were included that met the following criteria: (i) adult cancer patients and survivors (>18 yr old); (ii) HIIT or combined HIIT programs versus usual care; (iii) assessment of fatigue and pain. Cochrane tool was used for assessing Risk of Bias (RoB) and Review Manager (RevMan 5.2) was used for data analysis. RESULTS: Based on limited number (12) of studies included, we found HIIT and combined HIIT interventions have significant effect sizes on reducing both CRF (standardized mean difference, 0.63; 95% confidence interval, 0.42-0.84; P < 0.001) and cancer-associated pain (standardized mean difference, 0.44; 95% confidence interval, 0.25-0.63; P < 0.001). CONCLUSIONS: This systematic review and meta-analysis indicate that HIIT and combined HIIT programs can reduce CRF and pain.

Energy Costs of Household and Eldercare Activities in Young to Middle-Aged Chinese Adults.

BACKGROUND: The 2011 Compendium of Physical Activities provides metabolic equivalent (MET) values for household and eldercare activities (physical activities [PAs]). METs are from published studies, estimated if values are not published, or combined with other PAs with different METs in a single entry. Some PAs are missing from the Compendium. This study measures the energy costs for 15 household and eldercare PAs with estimated METs, PAs in combined entries, and new PAs. METHODS: Participants were 30 adults (14 males and 16 females), ages 22-58 years (33.7 [11.2] y). PAs were measured in a laboratory for 8 minutes with a 4-minute rest between PAs. A portable indirect calorimeter measured oxygen uptake (in milliliters per kilogram per minute). Standard METs were computed as activity VO2/3.5 mL·kg-1·min-1. RESULTS: Cooking, meal tasks, laundry, light cleaning, and watering plants ranged from 1.8 to 2.3 METs. Sweeping, walking, and carrying groceries and boxes on the ground and stairs ranged from 3.0 to 5.5 METs. Eldercare ranged from 1.8 to 3.0 METs. Measured METs differed from estimated values by ±0.3 to 2.2 METs. Most measured METs were lower than estimated METs. CONCLUSION: Updating estimated METs with measured values and separating PAs from combined entries increases the accuracy of household and eldercare PAs presented in the Compendium.

Relationship Between Gross Motor Skills and Inhibitory Control in Preschool Children: A Pilot Study.

Purpose: Gross motor skills (GMS) and inhibitory control (IC) which are both development in preschool stage is significant for preschooler to healthy growth. However, the evidence of relationship between them in preschoolers are still insufficient, most of studies only focus on youth. Thus, the aim of this research is to examine the association between GMS and IC in preschool children. Methods: This cross-sectional study used baseline data from a previous intervention study of preschoolers conducted in 2018. GMS were assessed by using the Test for Gross Motor Development (2nd edition) in preschoolers, which includes two subtests of locomotor and object control skills. Total GMS is calculated from the sum of these two subtests. The Fish Flanker task was used to evaluate both accuracy and reaction time of IC. Multivariate linear regression models were established to analyze the relationships between GMS and IC. Results: A total of 123 preschool-age children (55 girls, 68 boys) were included in the final analysis. After adjusting for confounders, GMS (ß = -8.27 ms, 95%CI: -14.2, -2.34), locomotor (ß = -11.2 ms, 95%CI: -21.43, -0.97), and object control skills (ß = -12.15 ms, 95%CI: -22.07, -2.23) were all negatively related with reaction time of IC. Conclusion: There was a significant negative correlation between gross motor skills and the reaction time of inhibitory control in preschool children. Further research is needed to verify this finding in prospective and experimental studies.

Energy Cost of Reclining, Sitting, and Standing Activities in Chinese Adults.

The 2011 Compendium presents MET values for sedentary behaviors (SBs) and light-intensity physical activities (LIPAs). Some entries have estimated METs, others have multiple activities in a single entry, and newer activities are not in the Compendium. Accurate MET values are needed to increase the validity and generalizability of the Compendium. This study measured and analyzed SBs and LIPAs' energy costs in reclining, sitting, standing postures, and fidgeting. Indirect calorimetry measured the energy costs (VO2, ml·kg-1.min-1) in 11 males and seven females (30.7 ± 7.6 y). Two groups of 9 participants each completed 17 randomly assigned activities (9 in group 1; 8 in group 2) for 5 minutes with a 2-minute rest between tasks. Standard METs were calculated as VO2 ml·kg-1.min-1/3.5 ml·kg-1.min-1. Results showed mean MET values for doing nothing (recline: 1.3, sit: 1.3. stand: 1.3); Watching TV on a mobile phone (recline: 1.3, sit: 1.3); Reading (recline; 1.5, sit: 1.0); Writing (recline: 1.5, sit: 1.3, stand: 1.3); Texting or viewing websites on a mobile phone (recline: 1.3, sit: 1.3, stand: 1.3); Fidgeting (sit hands only: 1.5, sit feet only: 1.8, stand hands and feet: 2.0); Typing (stand: 1.3). Measured vs. Compendium METs were the same for five SBs and LIPAs, higher for three SBs and LIPAs (by 0.2 METs), and lower for one SB (by 0.3 METs). In conclusion, the activities ranged from 1.0 to 2.0 METs, categorized as sedentary and light-intensity. Increasing the accuracy of Compendium MET values increases its utility for the correct classification of SB and LIPAs.

Effects of Traditional Chinese Exercise on Oxidative Stress in Middle-Aged and Older Adults: A Network Meta-Analysis.

OBJECTIVE: To evaluate the best option among traditional Chinese exercises for reducing oxidative stress in middle-aged and older adults, using a network meta-analysis. METHODS: PubMed, Web of Science, and CNKI databases were used. We searched randomized controlled trials (RCTs) on middle-aged and older adults to influence oxidative stress by any traditional Chinese exercises from the beginning to 20 January 2022. A network meta-analysis of randomized control trials was performed comparing the changes in the concentration of glutathione peroxidase (GPX), malondialdehyde (MDA), and superoxide dismutase (SOD) as primary outcomes, following different therapeutic interventions with traditional Chinese exercises in middle-aged and older adults over 30 years old. Standardized mean differences (SMD) and 95% confidence intervals (CI) were used to assess the correlation between each group of interventions, and surface under the cumulative ranking (SUCRA) was used to rank the best interventions. RESULTS: The meta-analysis comprised 15 trials with a total of 927 participants and six interventions: (Wuqinxi (WQX), Baduanjin (BDJ), Tai Ji Quan (TJQ), Yijinjing (YJJ), Mawangdui Daoyin (MWD), and no exercise intervention (NEI)). Regarding GPX: WQX [SMD = 2.79 (1.75, 3.83)], TJQ [SMD = 0.47 (0.23, 0.70)], YJJ [SMD = 1.78 (1.18, 2.37)], MWD [SMD = 1.89 (1.36, 2.43)] were superior in increasing GPX relative to NEI. Regarding MDA: WQX [SMD = 1.68 (0.94, 2.42)], YJJ [SMD = 0.99 (0.28, 1.69)] were superior in reducing MDA relative to NEI. Regarding SOD: WQX [SMD = 1.05 (0.10, 2.01)] were superior in increasing SOD relative to NEI. WQX topped the SUCRA with GPX: 0.97, MDA: 0.91, and SOD: 0.94. Furthermore, WQX was more effective than TJQ in interfering with GPX [SMD = 2.32 (1.26, 3.39)] and MDA [SMD = 1.47 (0.26, 2.67)], and a significantly better intervention effect on SOD than YJJ [SMD = 1.52 (0.80, 2.24)] and MWD [SMD = 0.89 (0.03, 1.75)]. CONCLUSION: Traditional Chinese exercise can help middle-aged and older adults reduce oxidative stress. WQX may be the best traditional Chinese exercise of the exercises evaluated for reducing oxidative stress in middle-aged and older adults.

Effects of Family Intervention on Physical Activity and Sedentary Behavior in Children Aged 2.5-12 Years: A Meta-Analysis.

Introduction: To use a quantitative approach to examine the effects of family interventions on physical activity (PA) and sedentary behavior (SB) in children aged 2. 5-12 years. Methods: PubMed, OVID, Web of Science, and others were searched from their inception to May 2020. Intervention studies that examined the effects of family interventions on PA among children aged 2.5-12 years were included in this meta-analysis. Lastly, subgroup analyses were conducted to examine the potential modifying effects of family intervention's characteristics and study quality. Results: Eleven articles met the inclusion criteria for this review. Studies investigated a range of PA outcomes, including moderate-to-vigorous PA (MVPA), total PA (TPA), daily steps, and SB levels. Meta-analysis showed that family intervention had a significant effect on PA [standardized mean difference (SMD) = 0.10; 95% CI = 0.01-0.19], especially for daily steps [weight means difference (WMD) = 1,006; 95% CI = 209-1,803], but not for SB (WMD = -0.38; 95% CI = -7.21-6.46). Subgroup analyses indicated the improvements in PA occurred when children were 6-12 years old, intervention focused on PA only, intervention duration ≤ 10 weeks, and "low risk of bias" study performed. Conclusions: Family intervention may be a promising way to promote children's PA levels, especially for daily steps. Trial Registration: Meta-analysis protocol was registered on PROSPERO: CRD42020193667.

Effects of interrupting prolonged sitting on postprandial glycemia and insulin responses: A network meta-analysis.

PURPOSE: This study aimed to evaluate the effectiveness of physical activity (PA) interrupting prolonged sitting (PS) on postprandial glycemia and insulin responses among adults. METHODS: PubMed, EMBASE, Cochrane Library, Web of Science, CINAHL, PsycINFO, and the China National Knowledge Infrastructure databases were searched through September 30, 2020. Randomized controlled trials (RCTs) that examined the effect of all forms of PA interrupting PS on postprandial glycemia and/or insulin responses among adults without chronic diseases were included in this study. The risk of bias of included studies was evaluated based on the Cochrane tool. A network meta-analysis was performed to estimate the summary standardized mean differences (SMDs) with 95% confidence intervals (95%CIs) with random effects. RESULTS: Thirty crossover RCTs were included in our review. These RCTs included 9 types of interventions that interrupted PS. When compared to PS by itself, light-intensity PA intermittent interrupting (LPA-INT) PS and moderate-intensity PA intermittent interrupting (MPA-INT) PS significantly lowered postprandial glycemia (SMD = -0.46, 95%CI: -0.70 to -0.21; SMD = -0.69, 95%CI: -1.00 to -0.37, respectively) and significantly reduced postprandial insulin response (SMD = -0.46, 95%CI: -0.66 to -0.26; SMD = -0.47, 95%CI: -0.77 to -0.17, respectively). Results of the clustered ranking plot indicated that MPA-INT was the most effective intervention in lowering postprandial glycemia and insulin responses. CONCLUSION: Replacing PS with MPA-INT or LPA-INT has a positive effect in reducing postprandial glycemia and insulin responses, with MPA-INT being the optimal intervention strategy.

The Association of Different Sedentary Patterns and Health-Related Physical Fitness in Pre-schoolers.

Background: The results of sedentary time (ST) and health-related physical fitness (HPF) are not completely consistent and the studies concentrated on pre-schoolers are very limited. Methods: We measured ST and ST patterns (ST Bouts time, ST Breaks times) by accelerometer. The health-related physical fitness T-score (HPFT) was calculated by five indexes: height-weight standard score, 20 m shuttle-run test, grip strength, standing long jump and 2 × 10 m shuttle-run test. Results: We included 375 pre-schoolers (211 boys, 164 girls) in the final analysis. The total ST and ST Bouts times negatively correlated with HPFT in pre-schoolers. HPFT reduced by 1.69 and 0.70 points per 10 min increased in total ST and ST Bouts times, respectively. HPFT of the highest quartile group reduced by 9.85 points in total ST, and 10.54 points in ST Bouts time compared with the lowest quartile group. However, the HPFT increased by 0.09 points per 10 times increased in ST Breaks times; the HPFT increased by 16.21 and 15.59 points when moderate to vigorous physical activity (MVPA) replaced total ST and ST Bouts time. Conclusions: HPF negatively correlated with the Total ST and ST Bouts times, but positively correlated with ST Breaks times; and HPF significantly improved when MVPA replaced ST in pre-schoolers.

Effects of Smartphone-Based Interventions on Physical Activity in Children and Adolescents: Systematic Review and Meta-analysis.

BACKGROUND: About 70% of children and adolescents worldwide do not meet the recommended level of physical activity (PA), which is closely associated with physical, psychological, and cognitive well-being. Nowadays, the use of technologies to change PA is of interest due to the need for novel, more effective intervention approaches. The previous meta-analyses have examined smartphone-based interventions and their impact on PA in adults, but evidence in children and adolescents still needs further research. OBJECTIVE: This systematic review and meta-analysis aimed to determine the effectiveness of smartphone-based interventions for improving PA in children and adolescents. METHODS: Five electronic databases (PubMed, Web of Science, OVID, Scopus, and the China National Knowledge Infrastructure) were searched up to June 29, 2020. Randomized controlled trials with a control group that examine the effect of smartphone interventions on PA among children and adolescents were included. Bias risks were assessed using the Cochrane collaboration tool. Meta-analysis was performed to assess the pooled effect on PA using a random effects model. Subgroup analyses were conducted to examine the potential modifying effects of different factors (eg, types of intervention, intervention duration, age, measurement, study quality). RESULTS: A total of 9 studies were included in this review, including 4 mobile app interventions, 3 SMS text messaging interventions, and 2 app + SMS text messaging interventions. In general, the risk of bias of included studies was low. Compared with the control group, the use of smartphone intervention significantly improved PA (standardized mean difference [SMD] 0.44, 95% CI 0.11-0.77, P=.009), especially for total PA (TPA; weighted mean difference [WMD] 32.35, 95% CI 10.36-54.33, P=.004) and daily steps (WMD 1185, 95% CI 303-2068, P=.008), but not for moderate-to-vigorous PA (WMD 3.91, 95% CI -1.99 to 9.81, P=.19). High statistical heterogeneity was detected (I2=73.9%, P<.001) for PA. Meta-regression showed that duration (ß=-.08, 95% CI -0.15 to -0.01, n=16) was a potential factor for high heterogeneity. The results of subgroup analyses indicated that app intervention (SMD 0.76, 95% CI 0.23-1.30, P=.005), children (SMD 0.64, 95% CI 0.10-1.18, P=.02), "≤8 weeks" (SMD 0.76, 95% CI 0.23-1.30, P=.005), objective measurement (SMD 0.50, 95% CI 0.09-0.91, P=.02), and low risk of bias (SMD 0.96, 95% CI 0.38-1.54, P=.001) can significantly improve PA. CONCLUSIONS: The evidence of meta-analysis shows that smartphone-based intervention may be a promising strategy to increase TPA and steps in children and adolescents. Currently, app intervention may be a more effective strategy among smartphone intervention technologies. To extend the promise of smartphone intervention, the future needs to design comparative trials among different smartphone technologies. TRIAL REGISTRATION: PROSPERO CRD42019148261; https://tinyurl.com/y5modsrd.

Walking pace and the risk of stroke: A meta-analysis of prospective cohort studies.

PURPOSE: The extent to which walking pace is associated with a reduced risk for stroke remains unclear. This study examined the association between walking pace and stroke risk based on prospective cohort studies. METHODS: Databases of PubMed, EMBASE, Web of Science, Scopus, and China National Knowledge Internet were searched from the inception dates to January 31, 2019, for prospective cohort studies focusing on walking pace and risk of stroke in adults. Two reviewers independently extracted data and assessed the quality of the studies. The dependent measure was stroke incidence. Using random-effects models, a meta-analysis was performed to estimate the overall relative risks (RR) of stroke incidence and 95% confidence intervals (CIs) for the individuals with the fastest walking paces vs. individuals with the slowest walking paces. A dose-response relationship was also examined. RESULTS: After screening 1294 titles/abstracts and 14 full-text studies identified in the search, 7 studies (from 8 cohorts) were included in the meta-analysis. The 7 studies included a total of 135,645 participants (95.2% women; mean age 63.6 years) and 2229 stroke events (median follow-up time = 8.0 years). Compared to individuals in the slowest walking-pace category (median = 1.6 km/h), individuals in the fastest walking-pace category (median = 5.6 km/h) had a 44% lower risk of stroke (pooled RR = 0.56, 95%CI: 0.48-0.65). There was also a linear dose-response relationship (RR = 0.87; 95%CI: 0.83-0.91), with the risk of stroke decreased by 13% for every 1 km/h increment in baseline walking pace. We observed similar results across walking-pace assessment, type of stroke ascertainment, stroke subtypes, sex, sample size, and duration of follow-up. CONCLUSION: Findings from this meta-analysis indicate that walking pace is inversely associated with the risk of stroke.