Effect of COVID-19 Pandemic Lockdowns on Body Mass Index of Primary School Children from Different Socioeconomic Backgrounds.

BACKGROUND: Childhood obesity is associated with various health outcomes. Restrictive measures to contain the spread of the Coronavirus Disease 2019 (COVID-19) pandemic, like lockdowns and school closures, affected children's daily structure, physical activity, dietary habits, and sleep quality, possibly exacerbating risk factors for childhood obesity and higher body mass index (BMI) in children. Poor socioeconomic conditions may have led to relatively higher risk for elevated BMI levels following pandemic measures. In this study, the impact of measures related to the COVID-19 pandemic on the BMI of third graders was investigated regarding children's socioeconomic background (SEB). METHODS: Data from 41,728 children (8.84 ± 0.56 years, 20,431 female) were collected in the context of a cohort study. Children were tested either before the pandemic (preCOVID: Sept2017-March2020, n = 26,314), or following the first (postLDI: Aug2020-Dec2020, n = 6657) or second lockdown in Germany (postLDII: Aug2021-Jan2022, n = 8757). SEB was based on the official school type classification of the state of Berlin. Outcome was BMI standard deviation scores (SDS). RESULTS: Significant effects of Time and SEB revealed elevated BMIs in postLDI (M = 0.23, p = 0.011) and postLDII (M = 0.22, p = 0.011) compared to preCOVID (M = 0.17) cohorts and higher BMIs for children with lower SEB (b = - 0.13, p < 0.001). A significant Time × SEB interaction indicated that the effect of SEB on children's BMI increased in response to lockdowns, especially in postLDII (b = - 0.05, p = 0.006). Results suggest that the COVID-19-related measures lead to increased BMI in children, and that children of lower SEB were at particular risk for higher BMIs following lockdowns. CONCLUSIONS: These findings highlight the dependency of children's BMI on societal circumstances. Over the course of two lockdowns in Germany, children have experienced BMI increments, particularly in low socioeconomic areas. Authorities are called into action to counteract increasing rates of childhood weight by promoting physical activity of children and establishing related post-pandemic offers.

Understanding the interplay between text quality, writing self-efficacy and writing anxiety in learners with and without migration background.

Writing presents considerable challenges to students' motivation. Yet there is a dearth of studies assessing the role of affect and motivation in writing performance for students with migration backgrounds (MB), who often underachieve in writing. Our study addressed this research gap by investigating the interplay between writing self-efficacy, writing anxiety, and text quality in 208 secondary students with and without MB using Response Surface Analyses. The data showed comparable levels of self-efficacy and, notably, lower writing anxiety levels among students with MB despite lower writing achievements. In the full sample, we observed positive correlations between self-efficacy and text quality and negative correlations between writing anxiety and text quality. When modeling efficacy and anxiety measures and their interplay to predict text quality, self-efficacy measures continued to account for statistically detectable unique variance in text quality, whereas writing anxiety did not. However, students with MB demonstrated differing interplay patterns, with less efficacious students with MB showing positive relations between writing anxiety and text quality.

A Skill Acquisition Perspective on the Impact of Exergaming Technology on Foundational Movement Skill Development in Children 3-12 Years: A Systematic Review and Meta-analysis.

BACKGROUND: Sedentary, digital screen time in children represents a major concern due to its detrimental effect on children's development. Nowadays, however, advances in technology allow children to actively interact with a digital screen using their whole body (e.g., exergaming), providing potential for movement learning. Exergaming technology may prove valuable in supporting children's development of foundational movement skills (FMS). OBJECTIVE: To examine the impact of exergaming technology on the development of FMS in children 3-12 years through a skill acquisition lens. METHODS: Systematic review and meta-analysis were conducted following the PRISMA guidelines. Web of Science, PubMed, PsycINFO and SPORTDiscus databases were searched between 2007 and 2022. Studies were eligible if they conducted an exergaming intervention to improve FMS in typically developing children aged three to twelve with a control group, using a baseline and post-intervention assessment design. FMS outcomes were pooled with a random effects model. RESULTS: Nine trials (4 RCTs, 2 cluster RCTs and 3 non-randomized trials) of varying methodological quality (2 had low, 6 had some concerns, and 1 had a high risk of bias) were included, with a total of 783 participants. FMS outcome measures across studies comprised object control skills, locomotor skills, coordination, agility, balance and balance-related skills. The meta-analysis included showed a small positive effect in favor of the exergaming intervention (r = 0.24 [95% confidence interval: 0.11-0.36]). CONCLUSION: Our results indicate that screen-based technology that requires an active engagement of the child can promote the development of FMS. Considering that FMS are the foundation of a child's physical, mental, health and academic development, this finding could lead to a reshaping of the perception of digital screen-based technology and the role this should play in children's lives. We speculate that the observed benefits most likely depend upon the quality of information-movement coupling specificity and the motor learning strategies built into the exergame and/or the intervention design. We do not believe this is dependent on the type of FMS being performed or the amount of practice. We recommend therefore that future research should examine how practitioners (school teachers, coaches and parents) can facilitate the interaction between a child and exergaming technology.

Physical activity promoting teaching practices and children's physical activity within physical education lessons underpinned by motor learning theory (SAMPLE-PE).

PURPOSE: Movement competence is a key outcome for primary physical education (PE) curricula. As movement development in children emerges through physical activity (PA), it is important to determine the extent of PA promotion within movement competence focused teaching pedagogies. Therefore, this study aimed to assess children's moderate-to-vigorous PA (MVPA) and related teaching practices in primary PE within Linear pedagogy and Nonlinear pedagogy and to compare this to current practice within PE delivery in primary schools. METHODS: Participants (n = 162, 53% females, 5-6y) were recruited from 9 primary schools within the SAMPLE-PE cluster randomised controlled trial. Schools were randomly-allocated to one of three conditions: Linear pedagogy, Nonlinear pedagogy, or control. Nonlinear and Linear pedagogy intervention schools received a PE curriculum delivered by trained deliverers over 15 weeks, while control schools followed usual practice. Children's MVPA was measured during 3 PE lessons (44 PE lessons in total) using an ActiGraph GT9X accelerometer worn on their non-dominant wrist. Differences between conditions for children's MVPA were analysed using multilevel model analysis. Negative binomial models were used to analyse teaching practices data. RESULTS: No differences were found between Linear pedagogy, Nonlinear pedagogy and the control group for children's MVPA levels during PE. Linear and Nonlinear interventions generally included higher percentages of MVPA promoting teaching practices (e.g., Motor Content) and lower MVPA reducing teaching practices (e.g., Management), compared to the control group. Teaching practices observed in Linear and Nonlinear interventions were in line with the respective pedagogical principles. CONCLUSIONS: Linear and Nonlinear pedagogical approaches in PE do not negatively impact MVPA compared to usual practice. Nevertheless, practitioners may need to refine these pedagogical approaches to improve MVPA alongside movement competence.

Foundational Movement Skills and Play Behaviors during Recess among Preschool Children: A Compositional Analysis.

This study aimed to examine the associations between play behaviors during preschool recess and foundational movement skills (FMS) in typically developing preschool children. One hundred and thirty-three children (55% male; mean age 4.7 ± 0.5 years) from twelve preschools were video-assessed for six locomotor and six object-control FMS using the Champs Motor Skill Protocol. A modified System for Observing Children's Activity and Relationships during Play assessed play behaviors during preschool recess. Associations between the composition of recess play behaviors with FMS were analyzed using compositional data analysis and linear regression. Results: Relative to time spent in other types of play behaviors, time spent in play without equipment was positively associated with total and locomotor skills, while time spent in locomotion activities was negatively associated with total and locomotor skills. No associations were found between activity level and group size play behavior compositions and FMS. The findings suggest that activity type play behaviors during recess are associated with FMS. While active games without equipment appear beneficial, preschool children may need a richer playground environment, including varied fixed and portable equipment, to augment the play-based development of FMS.

Effects of an 8-Week Intervention Targeting the Veridicality of Actual and Perceived Motor Competence Among Irish Adolescents in Project FLAME.

High levels of perceived motor competence and low levels of actual motor competence in youth populations have been reported world-wide. Both perceived and actual motor competence have been deemed independent correlates of health and physical activity (PA) behavior, and past research has indicated that their alignment may be linked to more consistent PA. Moreover, there is potential for a movement-based intervention to strengthen the alignment between perceived and actual motor competence, perhaps then guiding future health, PA, and community sport engagement globally. Thus, the objective of this study was to investigate the effectiveness of an 8-week movement-based intervention on increasing the alignment (i.e., veridicality) between PMC and AMC among Irish adolescent youth. We collected data on adolescents (n = 324; females = 149; M age = 14.5, SD = 0.88 years) across six second-level schools in Ireland, including measurements of actual and perceived, motor competence at pre- and post-intervention. We observed low levels of actual in contrast to high levels of perceived motor competence. We found a small but significant veridical alignment between perceived and actual motor competence, but there was no intervention effect on alignment. Future research should prioritize a longer intervention duration that targets student learning and understanding in order to develop veridical perceptions in adolescents that might sustain their participation in PA.

Effect of Linear and Nonlinear Pedagogy Physical Education Interventions on Children's Physical Activity: A Cluster Randomized Controlled Trial (SAMPLE-PE).

BACKGROUND: School-based interventions are a key opportunity to improve children's physical activity (PA); however, there is lack of evidence about how pedagogical approaches to motor learning in physical education (PE) might affect PA in children. Therefore, this study aimed to assess how different pedagogical approaches in PE might affect children's PA. METHODS: Participants (n = 360, 5-6 years) from 12 primary schools within the SAMPLE-PE randomized controlled trial were randomly allocated to either Linear Pedagogy (LP: n = 3) or Nonlinear Pedagogy (NP: n = 3) interventions, where schools received a 15-week PE intervention delivered by trained coaches, or to a control group (n = 6), where schools followed usual practice. ActiGraph GT9X accelerometers were used to assess PA metrics (moderate-to-vigorous PA, mean raw acceleration and lowest acceleration over the most active hour and half hour) over whole and segmented weeks at baseline, immediately post-intervention and 6 months follow-up. Intention to treat analysis employing multilevel modelling was used to assess intervention effects. RESULTS: LP and NP interventions did not significantly affect children's PA levels compared to the control group. CONCLUSION: PE interventions based on LP and NP alone might not be effective in improving habitual PA in children.

A Narrative Review of Motor Competence in Children and Adolescents: What We Know and What We Need to Find Out.

Lack of physical activity is a global public health problem causing not only morbidity and premature mortality, but it is also a major economic burden worldwide. One of the cornerstones of a physically active lifestyle is Motor Competence (MC). MC is a complex biocultural attribute and therefore, its study requires a multi-sectoral, multi-, inter- and transdisciplinary approach. MC is a growing area of research, especially in children and adolescents due to its positive association with a plethora of health and developmental outcomes. Many questions, however, remain to be answered in this field of research, with regard to: (i) Health and Developmental-related Associations of MC; (ii) Assessment of MC; (iii) Prevalence and Trends of MC; (iv) Correlates and Determinants of MC; (v) MC Interventions, and (vi) Translating MC Research into Practice and Policy. This paper presents a narrative review of the literature, summarizing current knowledge, identifying key research gaps and presenting questions for future investigation on MC in children and adolescents. This is a collaborative effort from the International Motor Competence Network (IMCNetwork) a network of academics and researchers aiming to promote international collaborative research and knowledge translation in the expansive field of MC. The knowledge and deliverables generated by addressing and answering the aforementioned research questions on MC presented in this review have the potential to shape the ways in which researchers and practitioners promote MC and physical activity in children and adolescents across the world.

Representative Percentile Curves of Physical Fitness From Early Childhood to Early Adulthood: The MoMo Study.

Introduction: Monitoring of physical fitness in youth is important because physical fitness is a summative indicator of health. From a developmental and preventive perspective, physical fitness levels are relatively stable from childhood to early adulthood. Thus, it is important to monitor physical fitness on a population based level being able to intervene at early stages (1). In order to reliably assess and evaluate the physical fitness of youth, a reliable system of standard values based on representative data is required. The aim of this analysis is to report sex- and age-specific physical fitness percentile curves from childhood to early adulthood in a nationwide sample in Germany. Methods: We use data from the nationwide representative Motorik Modul (MoMo) Study in Germany (data collection wave 1: 2009-2012; age: 4-23 years; n = 3,742; 50.1% female). Physical fitness was assessed by means of the MoMo test profile covering four dimensions of physical fitness (strength, endurance, coordination, and flexibility) and including eight physical fitness items. Percentile curves were fitted using the LMS transformation method of Cole and Green. Results: Standardized age- and sex-specific physical fitness percentiles were calculated for eight items: ergometric endurance testing, standing long jump, push-ups, sit-ups, jumping side-ways, balancing backwards, static stand, and stand and reach test. The physical fitness curves differ according to gender and the fitness dimension. Physical fitness improvements with age are linear (e.g., max. strength) or curvilinear (e.g., coordination) and have their stagnation points at different times over the course of adolescence. Discussion: Our results provide for the first time sex- and age-specific physical fitness percentile curves for Germany from 4 to 17 years. Differences in curve-shapes indicating a timed and capacity-specific physical fitness development. Nationwide German physical fitness percentiles can be useful in comparing different populations (e.g., cross-country), reporting secular trends, comparing special groups, and to evaluate physical fitness interventions.

Skill Acquisition Methods Fostering Physical Literacy in Early-Physical Education (SAMPLE-PE): Rationale and Study Protocol for a Cluster Randomized Controlled Trial in 5-6-Year-Old Children From Deprived Areas of North West England.

BACKGROUND: There is a need for interdisciplinary research to better understand how pedagogical approaches in primary physical education (PE) can support the linked development of physical, cognitive and affective aspects of physical literacy and physical activity behaviors in young children living in deprived areas. The Skill Acquisition Methods fostering Physical Literacy in Early-Physical Education (SAMPLE-PE) study aims to examine the efficacy of two different pedagogies for PE, underpinned by theories of motor learning, to foster physical literacy. METHODS: SAMPLE-PE will be evaluated through a cluster-randomized controlled trial targeting 5-6 year old children from schools located in areas of high deprivation in Merseyside, North-West England. Schools will be randomly allocated to one of three conditions: Linear Pedagogy, Non-linear Pedagogy, or Control. Non-linear and Linear Pedagogy intervention primary schools will receive a PE curriculum delivered by trained coaches over 15 weeks, while control schools will follow their usual practice. Data will be collected at baseline (T0), immediately post-intervention (T1), and 6 months after the intervention has finished (T2). Children's movement competence is the primary outcome in this trial. Secondary outcomes include physical activity, perceived competence, motivation, executive functions, and self-regulation. An extensive process evaluation will also examine implementation factors such as intervention context, reach, dose, fidelity and acceptability. DISCUSSION: The SAMPLE-PE project will enable better understanding surrounding how to operationalise physical literacy through enrichment of PE practices in early PE. The study will provide robust scientific evidence regarding the efficacy of underpinning PE pedagogy with theories of motor learning to promote the development of physical literacy. TRIAL REGISTRATION: Retrospectively registered on 5th September 2018 at ClinicalTrials.gov, a resource provided by the U.S. National Library of Medicine (Identifier: NCT03551366).

Conceptualising and testing the relationship between actual and perceived motor performance: A cross-cultural comparison in children from Australia and Germany.

Previous studies investigating the relationship between motor skill, physical activity and fitness in children have not thoroughly considered the role of self-perception. Therefore, the study aim was to test a theoretical framework, which considered both actual and perceived motor skill as well as actual and perceived fitness. Potential moderating effects of sex and country were considered. Data on motor skill, fitness, as well as self-perception of motor skill and fitness were collected from 145 Australian children and 214 German children (age range 7 to 10 years). For actual motor skill and fitness, mean differences for sex, age and country were found. For perceived motor performance (perceived motor skill and perceived fitness) no mean differences were found for age. Path analyses were performed. The final model showed significant relations between actual performance (object control skill, fitness) and perceived performance (object control skill, fitness). All model paths had low to moderate regression weights with the lowest relationship reported between actual and perceived fitness. Sex and country showed no effects. This integrated approach has led to a better understanding of the relationship between children's perceived and objective performance, and cultural differences within them.

The Influence of Fitness-App Usage on Psychological Well-Being and Body Awareness-A Daily Diary Randomized Trial.

Self-tracking via fitness apps is popular and has been described as a means to enhance body awareness and well-being. However, the effects of fitness-app use and specific app functions on well-being and body awareness have yet to be targeted in controlled experimental studies. In two randomized groups, a fitness tracker was used for 6 weeks, and in one group a daily step target was implemented. In a third control group, participants documented their physical activity. A daily diary method was used to measure well-being and body trusting. In Bayesian multilevel analyses, no time, group, or interaction effects were found. These results were robust when controlling for diverse variables. It can be concluded that exercise-related self-tracking and specific step goals do not substantially influence psychological well-being and body trusting. Considering the large variability in effects, potential effects can be assumed under conditions that are to be identified in further studies.

Pain-related Self-efficacy Among People With Back Pain: A Systematic Review of Assessment Tools.

BACKGROUND: Before an intervention can be implemented to improve pain-related self-efficacy, assessment is required. The aim of the present study was to provide a systematic review on which self-efficacy scales are being used among patients with back pain and to evaluate their psychometric properties. METHODS: A systematic search was executed in January 2019 and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 checklist served as a guide for conducting the study. Electronic databases included Cinahl, Medline, PubMed, PsycINFO, PSYNDEX, and SportDiscus. Publications in English or German language that focused on the adult patient population with back pain and which provided validation or reliability measures on pain-related self-efficacy were included. RESULTS: A total of 3512 records were identified resulting in 671 documents after duplicates were removed. A total of 233 studies were screened full-text, and a total of 47 studies addressing 19 different measures of pain-related self-efficacy were included in the quality analysis. The most commonly used instruments were the Pain Self-Efficacy Questionnaire and the Chronic Pain Self-Efficacy Scale. All studies reported internal consistency, but many studies lacked other aspects of reliability and validity. CONCLUSIONS: Further research should focus on assessing validity and interpretability of these questionnaires, especially in pain-related target groups. Researchers should select questionnaires that are most appropriate for their study aims and the back pain population and contribute to further validation of these scales to best predict future behavior and develop intervention programs. This systematic review aids selection of pain-related assessment tools in back pain both in research and practice.

Classes of developmental trajectories of body mass index: Differences in motor competence and cardiorespiratory fitness.

The purpose was to identify classes of different developmental trajectories of BMI and testing them for differences in motor competence (MC) and cardiorespiratory fitness (CRF), in children and adolescents (4 to 13 years of age). This was a 5 years' longitudinal study with six cohorts. One hundred and forty-seven children (69 girls) divided into six cohorts participated. At baseline, the youngest and the oldest cohorts had 4 and 11 years of age, respectively. Height and weight were assessed, and BMI was calculated. MC was assessed with KTK and TGMD-2, and CRF was assessed with one-mile run/walk. Developmental trajectories of BMI were identified using latent class linear-mixed modelling. Latent class membership was explained according to covariates of MC and CRF. Two meaningful classes were identified. Class 1 (78.92% of the participants) showed lower initial BMI and a lower slope compared to class 2 (21.08% of the participants) (all ps < 0.001). Class membership only predicted trajectories in motor coordination, with children in class 1 having a better development.In conclusion, this study identified two meaningful trajectories for children based on their BMI development across five time points. In line with previous research, children with slower increasing BMI showed better motor coordination improvements.

Are children with higher self-reported wellbeing and perceived motor competence more physically active? A longitudinal study.

OBJECTIVES: Self-perceptions such as perceived motor competence and psychosocial wellbeing have been identified as important to children's physical activity. The study's purpose was to explore whether perceived motor competence and psychosocial wellbeing were determinants of physical activity, one year after a baseline assessment. DESIGN: Longitudinal study. METHODS: A total of 134 children (65.7% boys, 34.3% girls) aged 6-7 years at baseline (2016), and 7-8 years at follow-up (2017) were included in this study. Pearson's correlations assessed associations at baseline and follow-up between moderate- to vigorous-intensity physical activity (MVPA) (accelerometers) and (i) total perceived motor competence and subdomains (the pictorial scale of Perceived Movement Skill Competence) and (ii) psychosocial wellbeing and sub-domains - KidKINDL KINDer Lebensqualitätsfragebogen: Children Quality of Life Questionnaire (KINDLR). Variables identified as significant in Pearson's correlations were included in mixed model analyses, adjusting for accelerometer wear time, sex and age. RESULTS: Baseline perceived object control skills was associated with MVPA at follow-up (r=0.38, p<0.001), but perceived locomotor skills were not. Self-esteem was the only subdomain of psychosocial wellbeing that demonstrated significant association with MVPA at baseline (r=0.21, p<0.05). Perceived object control (B=1.36, p=0.019, 95% CI [0.23, 2.50]) and self-esteem (B=0.32, p=0.001, 95% CI [0.13, 0.50]) positively predicted MVPA; albeit with small effects. CONCLUSIONS: Focusing on improving children's perceived object control and self-reported self-esteem may contribute to children's physical activity participation.

Validation of the vignette-based German Exercise Causality Orientation Scale (G-ECOS).

The Self-Determination Theory has been applied to explain behaviour in numerous contexts and cultures. In the exercise context, causality orientations (autonomy, control, impersonal) are important to describe individual differences in initiation and maintenance of health behaviour. The assessment of exercise causality orientations can be a key element to improve predictions of motivated health and exercise behaviour. Nevertheless, a scale to measure exercise causality orientations has not been established in German yet. Thus, it was the aim of the present work to translate the Exercise Causality Orientations Scale to German and to test it throughout three studies. The German G-ECOS questionnaire was cross-validated via confirmatory factor analyses in two separate samples. Both Study 1 (n = 306, 72.60% female, age M = 26.00, SD = 5.66; CFI = .96) and Study 2 (n = 320, 70.94% female, age M = 29.00, SD = 3.54; CFI = .95) indicated a good model fits. In a further Study 3 (n = 548, 62.50% female, age M = 30.17, SD = 11.91), the relations between exercise causality orientations and other SDT related constructs were examined. The correlations indicated positive associations between autonomy causality orientation and intrinsic regulation, intrinsic exercise participation goals, and exercise basic needs satisfaction. Overall, the assessment of exercise causality orientations can be useful in analysing and potentially predicting motivated exercise behaviour.

Mental Practice Ability Among Stroke Survivors: Investigation of Gender and Age.

Background: Mental practice refers to the imaginary representation of a motor action. Mental practice interventions are frequently used among stroke survivors to improve motor function. Individual characteristics that may determine whether a person is able to mentally perform a specific movement have been mainly spared in research. Aims: The aim of the present study is to examine whether gender and age are related to mental practice ability. Methods: The study has a cross-sectional design. Data collection was done via self-report questionnaires on mental practice ability, sociodemographic information, and perceived stroke impact. Data analysis was conducted in R using descriptive statistics and regression analysis. N = 44 stroke survivors (M = 65.8 years, SD = 11.4, range 48-88), n = 19 of which were female were recruited in two German neurologic rehabilitation facilities. Results: Age (ß = -0.13, p = 0.057) and gender (ß = 0.17, p = 0.260) were not associated with mental practice ability, when controlling for time since stroke and perceived stroke impact (Stroke Impact Scale). Perceived stroke impact was significantly related to mental practice ability (ß = 0.44, p = 0.004). Those who reported less stroke impact showed better mental practice ability. Conclusion: Mental practice ability may be preserved in stroke patients, irrespective of age and gender. We report cross-sectional data on mental practice ability in this study, thus the direction of the relationship between mental practice ability and perceived stroke impact is of interest. Future studies should aim at using a longitudinal design and bigger sample sizes.

Investigating the construct of motor competence in middle childhood using the BOT-2 Short Form: An item response theory perspective.

PURPOSE: Motor assessments generally produce a single motor competence score based on the general motor ability hypothesis, which states that motor competence is a one-dimensional trait underlying a wide range of motor skills. Yet, it is unclear whether the general motor ability hypothesis holds true in middle childhood, which is marked by an increased participation in sports and other types of physical activity. Therefore, the aim of the study was to evaluate the structure of motor competence in middle childhood using a test battery with a large item set. METHOD: A cross-sectional design was used to collect motor competence data of 2538 children aged 6-11 years. Participants completed the Bruininks-Oseretsky Test of Motor Proficiency-2nd Edition Short Form (BOT-2 SF), which consists of 14 skill items and covers different motor domains. In accordance with the BOT-2 SF manual, point scores were computed for each item. Polytomous Rasch analyses (ie, general partial credit model) were carried out to investigate the construct of motor competence. RESULTS: Rasch analyses revealed different items with unordered threshold parameters, due to ceiling effects. However, after empirically rescaling the category width for each item, follow-up analyses revealed a one-dimensional structure with 12 items. CONCLUSION: The study provides some evidence of a one-dimensional construct (ie, motor competence) underlying motor assessment in middle childhood. Continued efforts should be made to ensure that valid composite scores are used in motor assessment and to better understand the development of motor competence across childhood and into adolescence and adulthood.

Effects of different protocols of high intensity interval training for VO2max improvements in adults: A meta-analysis of randomised controlled trials.

OBJECTIVES: To examine the effects of different protocols of high-intensity interval training (HIIT) on VO2max improvements in healthy, overweight/obese and athletic adults, based on the classifications of work intervals, session volumes and training periods. DESIGN: Systematic review and meta-analysis. METHODS: PubMed, Scopus, Medline, and Web of Science databases were searched up to April 2018. Inclusion criteria were randomised controlled trials; healthy, overweight/obese or athletic adults; examined pre- and post-training VO2max/peak; HIIT in comparison to control or moderate intensity continuous training (MICT) groups. RESULTS: Fifty-three studies met the eligibility criteria. Overall, the degree of change in VO2max induced by HIIT varied by populations (SMD=0.41-1.81, p<0.05). When compared to control groups, even short-intervals (≤30s), low-volume (≤5min) and short-term HIIT (≤4weeks) elicited clear beneficial effects (SMD=0.79-1.65, p<0.05) on VO2max/peak. However, long-interval (≥2min), high-volume (≥15min) and moderate to long-term (≥4-12weeks) HIIT displayed significantly larger effects on VO2max (SMD=0.50-2.48, p<0.05). When compared to MICT, only long-interval (≥2min), high-volume (≥15min) and moderate to long-term (≥4-12weeks) HIIT showed beneficial effects (SMD=0.65-1.07, p<0.05). CONCLUSIONS: Short-intervals (≤30s), low-volume (≤5min) and short-term (≤4weeks) HIIT represent effective and time-efficient strategies for developing VO2max, especially for the general population. To maximize the training effects on VO2max, long-interval (≥2min), high-volume (≥15min) and moderate to long-term (≥4-12weeks) HIIT are recommended.