Effects of 28 weeks of high-intensity interval training during physical education classes on cardiometabolic risk factors in Chilean schoolchildren: a pilot trial

Effects of School-Based High-Intensity Interval Training on Hemodynamic Parameters and Heart Rate Variability: A Randomized Controlled Trial

ABSTRACT

Ketelhut, S, Ketelhut, K, Ketelhut, SR, and Ketelhut, RG. Effects of school-based high-intensity interval training on hemodynamic parameters and heart rate variability: A randomized controlled trial. J Strength Cond Res 38(6): 1033-1040, 2024-The purpose of this study was to assess the effects of a child-specific school-based high-intensity interval training (HIIT) implemented into physical education (PE) classes on various hemodynamic parameters and heart rate variability indices. Forty-six students (age 11 ± 1 year) were randomized into an intervention (INT n = 22) and a control group (CON n = 24). During a 12-week period, the INT and CON groups participated in regular PE twice weekly (45-90 minutes). The INT group received HIIT during the first 20 minutes of the 2 PE classes. Systolic and diastolic blood pressure, total peripheral resistance, aortic pulse wave velocity (aPWV), heart rate, SD of normal to normal heartbeat intervals, the root mean square of successive differences between normal heartbeats (RMSSD), the proportion of differences between adjacent normal to normal heartbeat intervals of more than 50 ms, low-frequency power, high-frequency power, and the LF/HF ratio were assessed before and after the experimental period. A p value ≤0.05 was considered statistically significant. Forty students (20 INT; 20 CON) were included in the analysis. A significant time × group interaction was detected for aPWV ( p = 0.05, η2 = 0.099), RMSSD ( p = 0.010, η2 = 0.161), low-frequency power ( p = 0.009, η2 = 0.165), high-frequency power ( p < 0.001, η2 = 0.272), and the LF/HF ratio ( p < 0.001, η2 = 0.354). The INT group revealed significant improvements for the respective parameters. School-based HIIT can induce improvements in cardiovascular parameters. These results highlight the potential of embedding HIIT within the school setting, offering a time-efficient exercise intervention.

Comparative effectiveness of school-based exercise interventions on physical fitness in children and adolescents: a systematic review and network meta-analysis

Background

Schools provide a favorable setting for health education, however, the most effective school-based exercise mode for improving physical fitness remains unclear. This network meta-analysis was designed to assess and rank the comparative efficacy of six exercise modalities on physical fitness indicators in a school-based setting.

Methods

An online search of the Web of Science, PubMed, SPORTDiscus, and Scopus databases was conducted. Randomized and quasi-randomized controlled trials were considered. Outcomes included measures of anthropometry and body composition, muscular fitness, and cardiorespiratory fitness. Data were pooled with a random effects model using the frequentist framework.

Results

A total of 66 studies with 8,578 participants (48% girls) were included. High-intensity interval training was the most effective intervention reducing body mass index (mean difference (MD) = -0.60 kg·m^-2, 95% confidence interval (95%CI) = -1.04 to -0.15, p = 0.009), elevating VO_2max (MD = 3.59 mL·kg^-1·min^-1, 95% CI = 2.45 to 4.74, p < 0.001), and 20-meter sprint performance (MD = -0.35 s, 95% CI = -0.55 to -0.14, p = 0.001). Aerobic training had the highest probability of reducing waist circumference (standardized mean difference (SMD) = -0.60, 95% CI = -0.88 to -0.32, p < 0.001). Active video games emerged as a promising modality for improving countermovement jump (MD = 2.43 cm, 95% CI = 0.06 to 4.80, p = 0.041) and shuttle running performance (SMD = 0.86, 95% CI = 0.29 to 1.43, p = 0.003). Strength training was the best exercise mode for improving standing long jump performance (SMD = 1.03, 95% CI = 0.07 to 1.98, p = 0.035) while combined training was rated the first for decreasing body fat percent (MD = -2.56%, 95% CI = -4.73 to -0.40, p = 0.022) and increasing push-up repetitions (SMD = 3.59, 95% CI = 0.81 to 6.37, p = 0.012).

Conclusion

School-based exercise interventions have multiple effects on physical fitness. The findings of this study will help to inform physical education teachers and coaches how best to deliver exercise programs in a school setting. Since the study was limited by the original research, the conclusions will require further verification using high-quality randomized controlled trials.

Systematic Review Registration

PROSPERO, Identifier: CRD42023401963.

Effects of a High Intensity Interval Training (HIIT) Program on Anthropomorphic and Cardiometabolic Variables in School Children with Overweight and Obesity

The aim of this study was to assess the effects of a high intensity interval training (HIIT) program on anthropomorphic and cardiometabolic variables in schoolchildren with overweight and obesity. A total of 443 schoolchildren (age: 6.37 ± 0.65 years) took part in this study. The experimental group (EG; n = 295; age = 6.40 ± 0.64 years) was compound with children with overweight and obesity, whereas children with normoweight were included in the control group (CG; n = 148; 6.31 ± 0.67 years). The EG performed a training program based on HIIT two times per week for 28 weeks (56 sessions), whilst the CG performed their habitual physical education classes based on the national curriculum. Body mass index (BMI), waist circumference, body fat, ∑ 4 skinfold fat, waist to height ratio, waist circumference, and cardiometabolic risk were measured. The dependent variables were analysed by two-way analysis of covariance (ANCOVA 2 × 2). To analyse the percentage differences between groups, the chi-square test was used. P-value was set at p < 0.05. Significant differences were found in the EG in BMI, waist circumference, body fat, ∑ 4 skinfold fat, and waist to height ratio. In conclusion, an HIIT training program can be an effective tool for improving anthropomorphic variables and reducing cardiometabolic risk in schoolchildren with overweight and obesity.

Prognostic Potential of the Body Composition Indices in Predicting Positive Changes in Resting Blood Pressure after High-Intensity Interval Training in Adolescents

This study aimed to investigate the prognostic potential of body composition indices in predicting the improvement in resting blood pressure after 10 weeks of high-intensity interval training (HIIT) implemented in physical education lessons. The participants were 141 adolescents aged 16 years. Independent variables were body mass index (BMI), fat mass index (FMI), muscle mass index (SMI), and mass to fat ratio (MFR); dependent variables were systolic and diastolic blood pressure (SBP, DBP) and its indices: pulse pressure (PP), mid-blood pressure (MBP), and mean arterial pressure (MAP). The receiver operating curve (ROC) method was employed. SMI and MFR are body composition indices with prognostic potential to predict positive changes in SBP in males (SMI: AUC = 0.82; p < 0.001, MFR = 0.70; p = 0.039) and MFR in females (AUC = 0.72; p = 0.035). The respective cut-off point values used to classify participants as a beneficiary of HIIT intervention concerning SBP were SMI = 7.84 and MFR = 2.43 in males, and for SMI = 10.12 and MFR = 1.94 in females. Body composition indices based on skeletal muscle (SMI, MFR) were more likely to predict positive changes in SBP after HIIT intervention in adolescents. PP, MBP, and MAP did not reflect the detecting power of SMI and MFR. However, these thresholds' utility is limited to adolescents of 16 years of age.

The Relative Importance of Age at Peak Height Velocity and Fat Mass Index in High-Intensity Interval Training Effect on Cardiorespiratory Fitness in Adolescents: A Randomized Controlled Trial

Background: This study aimed to evaluate the role of biological age in the relationship between preintervention fat mass and cardiorespiratory fitness effects (CRF) after High-Intensity Interval Training (HIIT) intervention in adolescents. Methods: A total of 141 boys and girls (16 years) were examined as control (CG) and experimental (EG) groups that conducted a 10-week HIIT implemented in physical education. Measurements: body height, body weight, fat mass index (FMI), CRF (Harvard Step Test). Predicted age at peak height velocity (APHV) was calculated. Pathway analyses were conducted to identify the influences of the measured variables. Results: APHV harmed the level of ΔFI (fitness index) (β = −0.270; p = 0.035), while HIIT had a positive effect on changes in ΔFI (β = 0.246; p = 0.002). Sex affected the changes in CRF (β = 0.344; p = 0.011). Two models were designed respective to sex. The effect of the APHV on ΔFI in girls was close to significant (p = 0.053) but was non-significant in boys (p = 0.311). Changes in CRF in girls were positively and close to significance (p < 0.100) affected by FMIbaseline. Conclusion: HIIT is an effective way of exerting positive changes in CRF in adolescents, which is greater in boys than girls. APHV plays a role only in girls. The HIIT should be tailored to girls depending on their maturity status.

School-based high-intensity interval training programs in children and adolescents: A systematic review and meta-analysis

PURPOSE

1) To investigate the effectiveness of school-based high-intensity interval training (HIIT) interventions in promoting health outcomes of children and adolescents compared with either a control group or other exercise modality; and 2) to explore the intervention characteristics and process outcomes of published school-based HIIT interventions.

METHODS

We searched Medline, Embase, CINAHL, SPORTDiscus, and Web of Science from inception until 31 March 2021. Studies were eligible if 1) participants aged 5-17 years old; 2) a HIIT intervention within a school setting ≥ 2 weeks duration; 3) a control or comparative exercise group; 4) health-related, cognitive, physical activity, nutrition, or program evaluation outcomes; and 5) original research published in English. We conducted meta-analyses between HIIT and control groups for all outcomes with ≥ 4 studies and meta-regressions for all outcomes with ≥ 10 studies. We narratively synthesised results between HIIT and comparative exercise groups.

RESULTS

Fifty-four papers met eligibility criteria, encompassing 42 unique studies (35 randomised controlled trials; 36 with a high risk of bias). Meta-analyses indicated significant improvements in waist circumference (mean difference (MD) = -2.5cm), body fat percentage (MD = -1.7%), body mass index (standardised mean difference (SMD) = -1.0), cardiorespiratory fitness (SMD = +1.0), resting heart rate (MD = -5bpm), homeostatic model assessment-insulin resistance (MD = -0.7), and low-density lipoprotein cholesterol (SMD = -0.9) for HIIT compared to the control group. Our narrative synthesis indicated mixed findings between HIIT and other comparative exercise groups.

CONCLUSION

School-based HIIT is effective for improving several health outcomes. Future research should address the paucity of information on physical activity and nutrition outcomes and focus on the integration and long-term effectiveness of HIIT interventions within school settings.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42018117567.

Effects of High-Intensity Interval Training in School on the Physical Performance and Health of Children and Adolescents: A Systematic Review with Meta-Analysis

Background

Performance of high-intensity interval training (HIIT) by children and adolescents improves physical and health-related fitness, as well as cardiometabolic risk factors.

Objectives

To assess the impact of HIIT performed at school, i.e. both in connection with physical education (intra-PE) and extracurricular sports activities (extra-PE), on the physical fitness and health of children and adolescents.

Methods

PubMed and SPORTDiscus were searched systematically utilizing the following criteria for inclusion: (1) healthy children and adolescents (5–18 years old) of normal weight; (2) HIIT performed intra- and/or extra-PE for at least 5 days at an intensity ≥ 80% of maximal heart rate (HR_max) or peak oxygen uptake (VO_2peak) or as Functional HIIT; (3) comparison with a control (HIIT versus alternative interventions); and (4) pre- and post-analysis of parameters related to physical fitness and health. The outcomes with HIIT and the control interventions were compared utilizing Hedges’ g effect size (ES) and associated 95% confidence intervals.

Results

Eleven studies involving 707 participants who performed intra-PE and 388 participants extra-PE HIIT were included. In comparison with the control interventions, intra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 5.89 ± 5.67 (range 1.88–9.90); ES number of push-ups: 6.22 (range n.a.); ES number of sit-ups: 2.66 ± 2.02 (range 1.24–4.09)), as well as ES fasting glucose levels (− 2.68 (range n.a.)) more effectively, with large effect sizes. Extra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 1.81 (range n.a.); ES number of sit-ups: 2.60 (range n.a.)) to an even greater extent, again with large effect sizes. Neither form of HIIT was more beneficial for parameters related to cardiorespiratory fitness than the control interventions.

Conclusion

Compared to other forms of exercise (e.g. low-to-moderate-intensity running or walking), both intra- and extra-PE HIIT result in greater improvements in neuromuscular and anaerobic performance, as well as in fasting levels of glucose in school children.

The high-intensity interval training introduced in physical education lessons decrease systole in high blood pressure adolescents

Increased resting blood pressure (BP) is a risk factor for many health complications. The prevalence of elevated BP is growing among adolescents. There is a need to investigate effective ways of decreasing excessive blood pressure in this age group. The study aim was to determine the effect of 10-weeks High-Intensive Interval Training (HIIT)—Tabata protocol—introduced in physical education (PE) lessons on resting blood pressure in adolescents. The sample included 52 boys aged 16.23 ± 0.33 years body height176.74 ± 6.07 (m), body weight 65.42 ± 12.51 (kg), BMI 20.89 ± 3.53 (kg/m²) and 89 girls aged 16.12 ± 0.42 years, body height 164.38 ± 6.54 (m), body weight 56.71 ± 10.23 (kg), BMI 20.93 ± 3.08 (kg/m²) from secondary school. Based on resting BP, the fractions of boys and girls with normal BP and high BP were identified and divided into experimental (EG) and control (CG) groups. EG completed a 10-weeks HIIT program (three cycles of Tabata protocol) implemented in one PE lesson during a week. The duration of the effort was 14 min. The intensity was at 75–80% of maximal heart rate. Changes in systolic and diastolic BP after the experiment were examined. The results indicated the improvement in SBP in EG with high BP compared to the rest of the groups (average reduction of 12.77 mmHg; p < 0.0001). The EG normotensive had a statistically significant higher reduction of SBP comparing CG normotensive (average decrease of 1.81 mmHG; p = 0.0089). HIIT effectively decreases BP in adolescents. Implementing HIIT in PE lessons in secondary school is recommended to improve BP parameters.

School-based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6 to 18

BACKGROUND

Physical activity among children and adolescents is associated with lower adiposity, improved cardio-metabolic health, and improved fitness. Worldwide, fewer than 30% of children and adolescents meet global physical activity recommendations of at least 60 minutes of moderate to vigorous physical activity per day. Schools may be ideal sites for interventions given that children and adolescents in most parts of the world spend a substantial amount of time in transit to and from school or attending school.

OBJECTIVES

The purpose of this review update is to summarise the evidence on effectiveness of school-based interventions in increasing moderate to vigorous physical activity and improving fitness among children and adolescents 6 to 18 years of age. Specific objectives are: • to evaluate the effects of school-based interventions on increasing physical activity and improving fitness among children and adolescents; • to evaluate the effects of school-based interventions on improving body composition; and • to determine whether certain combinations or components (or both) of school-based interventions are more effective than others in promoting physical activity and fitness in this target population.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, BIOSIS, SPORTDiscus, and Sociological Abstracts to 1 June 2020, without language restrictions. We screened reference lists of included articles and relevant systematic reviews. We contacted primary authors of studies to ask for additional information.

SELECTION CRITERIA

Eligible interventions were relevant to public health practice (i.e. were not delivered by a clinician), were implemented in the school setting, and aimed to increase physical activity among all school-attending children and adolescents (aged 6 to 18) for at least 12 weeks. The review was limited to randomised controlled trials. For this update, we have added two new criteria: the primary aim of the study was to increase physical activity or fitness, and the study used an objective measure of physical activity or fitness. Primary outcomes included proportion of participants meeting physical activity guidelines and duration of moderate to vigorous physical activity and sedentary time (new to this update). Secondary outcomes included measured body mass index (BMI), physical fitness, health-related quality of life (new to this update), and adverse events (new to this update). Television viewing time, blood cholesterol, and blood pressure have been removed from this update.  DATA COLLECTION AND ANALYSIS: Two independent review authors used standardised forms to assess each study for relevance, to extract data, and to assess risk of bias. When discrepancies existed, discussion occurred until consensus was reached. Certainty of evidence was assessed according to GRADE. A random-effects meta-analysis based on the inverse variance method was conducted with participants stratified by age (children versus adolescents) when sufficient data were reported. Subgroup analyses explored effects by intervention type.

MAIN RESULTS

Based on the three new inclusion criteria, we excluded 16 of the 44 studies included in the previous version of this review. We screened an additional 9968 titles (search October 2011 to June 2020), of which 978 unique studies were potentially relevant and 61 met all criteria for this update. We included a total of 89 studies representing complete data for 66,752 study participants. Most studies included children only (n = 56), followed by adolescents only (n = 22), and both (n = 10); one study did not report student age. Multi-component interventions were most common (n = 40), followed by schooltime physical activity (n = 19), enhanced physical education (n = 15), and before and after school programmes (n = 14); one study explored both enhanced physical education and an after school programme. Lack of blinding of participants, personnel, and outcome assessors and loss to follow-up were the most common sources of bias.  Results show that school-based physical activity interventions probably result in little to no increase in time engaged in moderate to vigorous physical activity (mean difference (MD) 0.73 minutes/d, 95% confidence interval (CI) 0.16 to 1.30; 33 studies; moderate-certainty evidence) and may lead to little to no decrease in sedentary time (MD -3.78 minutes/d, 95% CI -7.80 to 0.24; 16 studies; low-certainty evidence). School-based physical activity interventions may improve physical fitness reported as maximal oxygen uptake (VO₂max) (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82; 13 studies; low-certainty evidence). School-based physical activity interventions may result in a very small decrease in BMI z-scores (MD -0.06, 95% CI -0.09 to -0.02; 21 studies; low-certainty evidence) and may not impact BMI expressed as kg/m² (MD -0.07, 95% CI -0.15 to 0.01; 50 studies; low-certainty evidence). We are very uncertain whether school-based physical activity interventions impact health-related quality of life or adverse events.

AUTHORS' CONCLUSIONS

Given the variability of results and the overall small effects, school staff and public health professionals must give the matter considerable thought before implementing school-based physical activity interventions. Given the heterogeneity of effects, the risk of bias, and findings that the magnitude of effect is generally small, results should be interpreted cautiously.

Effekte von hochintensivem Intervalltraining (HIIT) auf Body-Mass-Index (BMI) und Körperfettanteil von übergewichtigen und adipösen Kindern – eine systematische Übersichtsarbeit

Hintergrund Mehr als 340 Millionen Kinder gelten weltweit als übergewichtig oder adipös, ihre Anzahl nahm in den letzten Jahren – auch durch die Coronapandemie – erheblich zu. Eine alternative Behandlung zur Reduzierung des Übergewichts, die in den Empfehlungen bisher keine große Beachtung findet, stellt das sogenannte hochintensive Intervalltraining (HIIT) dar.

Ziel Darstellung der Wirksamkeit von hochintensivem Intervalltraining auf den BMI und Körperfettanteil übergewichtiger und adipöser Kinder im Alter von 6–13 Jahren.

Methode Die Erstellung der systematischen Übersichtsarbeit orientierte sich an den PRISMA-Guidelines. Für die Literaturrecherche wurden die Datenbanken MEDLINE, Cochrane Library, CINAHL, Embase, Sports Medicine & Education Index und Web of Science nach Studien mit hochintensivem Intervalltraining für übergewichtige und adipöse Kinder durchsucht. Die Bewertung der methodischen Studienqualität erfolgte mittels PEDro-Skala, MINORS und Risk of Bias. Die Berichtsqualität wurde anhand von CONSORT und TREND bewertet.

Ergebnisse Es wurden 6 randomisierte kontrollierte Studien und 2 kontrollierte klinische Studien mit 479 HIIT-Teilnehmenden betrachtet. Diese zeigten, dass hochintensives Intervalltraining positive Auswirkungen auf den BMI und Körperfettanteil übergewichtiger und adipöser Kinder hat.

Schlussfolgerung Hochintensives Intervalltraining ist eine kinderfreundliche und zugleich effektive Alternative zur Behandlung von übergewichtigen und adipösen Kindern. Weitere klinische Studien sind erforderlich, um die Ergebnisse zu bekräftigen.

Physiotherapy and related management for childhood obesity: A systematic scoping review

INTRODUCTION

Despite targeted efforts globally to address childhood overweight/obesity, it remains poorly understood and challenging to manage. Physiotherapists have the potential to manage children with obesity as they are experts in movement and physical activity. However, their role remains unclear due to a lack of physiotherapy-specific guidelines. This scoping review aims to explore existing literature, critically appraising and synthesising findings to guide physiotherapists in the evidence-based management of childhood overweight/obesity.

METHOD

A scoping review was conducted, including literature up to May 2020. A review protocol exists on Open Science Framework at https://osf.io/fap8g/. Four databases were accessed including PubMed, Embase, CINAHL, Medline via OVID, with grey literature searched through google via "file:pdf". A descriptive synthesis was undertaken to explore the impact of existing interventions and their efficacy.

RESULTS

From the initial capture of 1871 articles, 263 intervention-based articles were included. Interventions included qualitative focused physical activity, quantitative focused physical activity and multicomponent interventions. Various outcome measures were utilised including health-, performance- and behaviour-related outcomes. The general trend for physiotherapy involvement with children who are obese appears to favour: 1) multicomponent interventions, implementing more than one component with environmental modification and parental involvement and 2) quantitative physical activity interventions, focusing on the quantity of bodily movement. These approaches most consistently demonstrated desirable changes across behavioural and health-related outcome measures for multicomponent and quantitative physical activity interventions respectively.

CONCLUSION

When managing children with obesity, physiotherapists should consider multicomponent approaches and increasing the quantity of physical activity, given consistent improvements in various obesity-related outcomes. Such approaches are well suited to the scope of physiotherapists and their expertise in physical activity prescription for the management of childhood obesity. Future research should examine the effect of motor skill interventions and consider the role of environmental modification/parental involvement as factors contributing to intervention success.

A Multicomponent Intervention Program With Overweight and Obese Adolescents Improves Body Composition and Cardiorespiratory Fitness, but Not Insulin Biomarkers

Objective: To verify the effect of a multicomponent intervention with overweight/obese adolescents on physical fitness, body composition, and insulin biomarkers.

Methods: A quasi-experimental study with 37 adolescents, aged 10 to 17 years, of both sexes, overweight and obese, allocated in two groups (Intervention—IG Group, n = 17; Control—GC Group, n = 20). The IGs were submitted to a multicomponent intervention for 6 months (three weekly sessions) consisting of physical exercises (sports, functional circuit, recreational, and water activities) and nutritional and psychological guidance. Participants were assessed before and after intervention on body composition [body mass index (BMI), body fat, waist circumference, and waist-to-hip ratio (WHR)], physical fitness [cardiorespiratory fitness (CRF) and abdominal strength], and biomarkers of insulin (glucose, insulin, evaluation of the homeostasis model of insulin, and resistin resistance). The prevalence of responders in both groups was obtained according to the theoretical model applied in previous studies similar to this one to determine the cutoff points for response to intervention. Poisson regression was used to verify the difference in the prevalence ratio (PR) of the interviewees between the groups.

Results: The responders' prevalence between groups CG and IG showed significant differences for body fat (CG = 30.0%; IG = 70.6%; PR = 1.396; p < 0.001), WHR (CG = 30.0%; IG = 76.5%; PR = 1.730; p < 0.001), and CRF (CG = 15.0%; IG = 52.5%; PR = 1.580; p < 0.001).

Conclusions: A 6-month multicomponent intervention program improved certain body composition parameters and the CRF of overweight and obese adolescents but did not improve insulin biomarkers.

Clinical Trial Registration: Clinical Trials under Protocol ID: 54985316.0.0000.5343.

Time-efficient intervention to improve older adolescents' cardiorespiratory fitness: findings from the 'Burn 2 Learn' cluster randomised controlled trial

BACKGROUND

Cardiorespiratory fitness (CRF) is an important marker of current and future health status. The primary aim of our study was to evaluate the impact of a time-efficient school-based intervention on older adolescents' CRF.

METHODS

Two-arm cluster randomised controlled trial conducted in two cohorts (February 2018 to February 2019 and February 2019 to February 2020) in New South Wales, Australia. Participants (N=670, 44.6% women, 16.0±0.43 years) from 20 secondary schools: 10 schools (337 participants) were randomised to the Burn 2 Learn (B2L) intervention and 10 schools (333 participants) to the control. Teachers in schools allocated to the B2L intervention were provided with training, resources, and support to facilitate the delivery of high-intensity interval training (HIIT) activity breaks during curriculum time. Teachers and students in the control group continued their usual practice. The primary outcome was CRF (20 m multi-stage fitness test). Secondary outcomes were muscular fitness, physical activity, hair cortisol concentrations, mental health and cognitive function. Outcomes were assessed at baseline, 6 months (primary end-point) and 12 months. Effects were estimated using mixed models accounting for clustering.

RESULTS

We observed a group-by-time effect for CRF (difference=4.1 laps, 95% CI 1.8 to 6.4) at the primary end-point (6 months), but not at 12 months. At 6 months, group-by-time effects were found for muscular fitness, steps during school hours and cortisol.

CONCLUSIONS

Implementing HIIT during curricular time improved adolescents' CRF and several secondary outcomes. Our findings suggest B2L is unlikely to be an effective approach unless teachers embed sessions within the school day.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12618000293268).

School-Based Exercise Intervention Improves Blood Pressure and Parameters of Arterial Stiffness in Children: A Randomized Controlled Trial

PURPOSE

To evaluate the effectiveness of a school-based exercise intervention on endurance performance (EP), blood pressure (BP), and arterial stiffness in children.

METHODS

A total of 105 students (mean age = 8.2 [0.6] y; 51% girls; body mass index = 17.8 [3.0] kg/m2) were randomized to the intervention group (IG, n = 51) and control group (CG, n = 54). During a 37-week experimental period, the IG received an exercise intervention (2 × 45 min/wk) in addition to their regular school physical education class (3 × 45 min/wk). EP, peripheral and central BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were assessed.

RESULTS

Following the intervention, significant changes (P < .05) in EP, peripheral and central systolic BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were found in the IG. Children in the CG displayed significant changes in peripheral and central diastolic BP. An analysis of the baseline-to-post changes revealed significant between-group differences in EP (P < .001), pulse pressure (P = .028), augmentation pressure (P = .007), and aortic pulse wave velocity (P = .037) that favored the IG and in peripheral and central diastolic BP that favored the CG.

CONCLUSION

The school-based exercise intervention had beneficial effects not only on EP but also on different hemodynamic parameters.

Association of Physical Education With Improvement of Health-Related Physical Fitness Outcomes and Fundamental Motor Skills Among Youths: A Systematic Review and Meta-analysis

IMPORTANCE

Whether quality- or quantity-based physical education (PE) interventions are associated with improvement of health-related physical fitness outcomes and fundamental motor skills (FMSs) in children and adolescents is unknown.

OBJECTIVE

To examine the association of interventions aimed at optimizing PE in terms of quality (teaching strategies or fitness infusion) or quantity (lessons per week) with health-related physical fitness and FMSs in children and adolescents.

DATA SOURCES

For this systematic review and meta-analysis, studies were identified through a systematic search of Ovid MEDLINE, Embase, Cochrane Controlled Trials Registry, and SPORTDiscus databases (from inception to October 10, 2019) with the keywords physical education OR PE OR P.E. AND fitness AND motor ability OR skills. Manual examination of references in selected articles was also performed.

STUDY SELECTION

Studies that assessed the association of quality- or quantity-based PE interventions with improvement in physical fitness and/or FMSs in youths (aged 3-18 years) were included.

DATA EXTRACTION AND SYNTHESIS

Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Random-effects models were used to estimate the pooled effect size (Hedges g).

MAIN OUTCOMES AND MEASURES

Health-related physical fitness outcomes and FMSs.

RESULTS

Fifty-six trials composed of 48 185 youths (48% girls) were included in the meta-analysis. Quality-based PE interventions were associated with small increases in health-related physical fitness (cardiorespiratory fitness [Hedges g = 0.24; 95% CI, 0.16-0.32] and muscular strength [Hedges g = 0.19; 95% CI, 0.09-0.29]) and FMSs (Hedges g = 0.38; 95% CI, 0.27-0.49). Subgroup analyses found stronger associations for quality-based PE interventions on body mass index (Hedges g = -0.18; 95% CI, -0.26 to -0.09), body fat (Hedges g = -0.28; 95% CI, -0.37 to -0.18), cardiorespiratory fitness (Hedges g = 0.31; 95% CI, 0.23-0.39), and muscular strength (Hedges g = 0.29; 95% CI, 0.18-0.39). Quantity-based PE interventions were associated with small increases in only cardiorespiratory fitness (Hedges g = 0.42; 95% CI, 0.30-0.55), muscular strength (Hedges g = 0.20; 95% CI, 0.08-0.31), and speed agility (Hedges g = 0.29; 95% CI, 0.07-0.51).

CONCLUSIONS AND RELEVANCE

The findings suggest that quality-based PE interventions are associated with small increases in both student health-related physical fitness components and FMSs regardless of frequency or duration of PE lessons. Because PE aims to improve more than health, high levels of active learning time may need to be balanced with opportunities for instruction, feedback, and reflection.

Classroom-Based Micro-Sessions of Functional High-Intensity Circuit Training Enhances Functional Strength but Not Cardiorespiratory Fitness in School Children-A Feasibility Study

The present study assessed the short-term effect of 6 min classroom-based micro-sessions of multi-joint functional high-intensity circuit training (FunctionalHIIT) performed by students during regular classes on parameters related to functional strength and cardiorespiratory fitness. In this randomized controlled 4-week study, 17 students (11 male; 6 female; age: 11.6 ± 0.2 years) performed 6 min of FunctionalHIIT (targeting >17 on the Borg scale) 4 days per week during regular school classes and 18 students (11 male; 7 female; age: 11.7 ± 0.3 years) served as control group (CG) without any additional in-class physical activity. The FunctionalHIIT group completed 86% of all planned sessions (mean duration: 6.0 ± 1.5 min) with a mean RPE of 17.3 ± 2.1. Body height, mass and BMI did not differ between the groups at baseline or between pre- and post-testing (p > 0.05; eta2 ≤ 0.218). The performances in lateral jumping (p < 0.000; part eta2 = 0.382; Δ% 4.6 ± 8.6), sit-ups (p < 0.000; part eta2 = 0.485; Δ% 3.1 ± 8.6) and 20-m sprints (p < 0.000; part eta2 = 0.691; Δ% 15.8 ± 5.4) improved in both groups with greater increase following FunctionalHIIT. No baseline differences and no interaction effects occurred in performance of 6 min run, flexibility, push-ups, balance, and long jump. Classroom-based FunctionalHIIT sessions, performed 4 days per week during 4 weeks did not improve variables related to aerobic endurance performance but enhanced certain parameters of functional strength in schoolchildren. As time is limited in the educational system of schools, FunctionalHIIT during regular school classes could offer a new perspective for increasing functional strength in schoolchildren.

Response of obese schoolchildren to high-intensity interval training applied in the school context

BACKGROUND

High-intensity interval training (HIIT) has been widely used to fight cardiovascular risk factors in adolescents and adults, but no data are available on its applicability in children.

OBJECTIVES

To assess the effects of HIIT on different anthropometric and cardiovascular parameters of overweight and obese children aged 7-9 years.

MATERIAL AND METHODS

Four groups were formed: 1) an overweight control group (OWCG, n=30, BMI=21.60±3.72kg/m²); 2) an obesity control group (OCG, n=34, BMI=23.92±3.11kg/m²); 3) an overweight intervention group (OWIG, n=69, BMI=20.01±1.88kg/m²), and 4) an obesity intervention group (OIG, n=141, BMI=24.12±2.66kg/m²). BMI, body fat (BF), waist circumference, height-waist ratio, systolic and diastolic blood pressure and cardiorespiratory fitness (CRF) were assessed before and after intervention.

RESULTS

There were significant differences in BMI (P<.001), BF (P<.001), and CRF (P<.001) between the groups (control vs. intervention) before and after intervention (OWCG vs. OWIG and OCG vs. OIG). BMI decreased in the OWIG (BMI, 20.01±1.88 at baseline vs. 19.00±2.02 after HIIT, P<.001) and OIG (BMI, 24.12±2.66 at baseline vs. 23.23±3.23 after HIIT, P<.001) groups. Similarly, BF decreased in the OWIG (BF, 21.84±4.97 at baseline vs. 19.55±4.81% after HIIT, P<.001) and OIG (BF, 30.26±11.49 at baseline vs. 26.81±6.80% after HIIT, P<.001) groups. CRF improved in both intervention groups (P<.001). There was a significant decrease in the prevalence rate of schoolchildren with obesity (from 66.4% to 49.6%) (P<.001).

CONCLUSION

The intervention conducted in the school setting improved the anthropometric and cardiovascular parameters of schoolchildren, and also allowed for reducing the proportion of schoolchildren with obesity.

Effect of a community-based childhood obesity intervention program on changes in anthropometric variables, incidence of obesity, and lifestyle choices in Spanish children aged 8 to 10 years

Results of community-based childhood obesity intervention programs do not provide strong evidence for their effectiveness. In this study, we evaluated the effect of the Thao-Child Health Program (TCHP), a community-based, multisetting, multistrategy intervention program for healthy weight development and lifestyle choices. In four Catalan cities, a total of 2250 children aged 8 to 10 years were recruited. Two cities were randomly selected for the TCHP intervention, and two cities followed usual health care policy. Children were selected from 41 elementary schools. Weight, height, and waist circumference were measured at baseline and after a mean follow-up of 15 months. Physical activity and adherence to the Mediterranean diet were measured with validated questionnaires. Generalized estimating equations (GEE) models were fitted to determine the intervention's effect on body mass index (BMI) z-score, waist-to-height ratio, Mediterranean diet adherence, and physical activity. Fully adjusted models revealed that the intervention had no significant effect on the BMI z-score, incidence of general and abdominal obesity, Mediterranean diet adherence, and physical activity. Waist-to-height ratio was significantly lower in controls than in the intervention group at follow-up (p < 0.004).

CONCLUSIONS

The TCHP did not improve weight development, diet quality, and physical activity in the short term. What is Known: • There is inconsistent evidence for the efficacy of school-based childhood obesity prevention programs. • There is little evidence on the efficacy of childhood obesity intervention programs in other settings. What is New: • This paper contributes information about the efficacy of a multisetting and multistrategy Community Based Intervention (CBI) program that uses the municipality as its unit of randomization. • This CBI had no effect on the prevention and treatment of childhood obesity in the short term.