Efficacy of School-Based Interventions for Improving Muscular Fitness Outcomes in Adolescent Boys: A Systematic Review and Meta-analysis

Physical activity and sedentary behavior among school-going adolescents in low- and middle-income countries: insights from the global school-based health survey

Background

The Global School Student Health Survey (GSHS) is being carried out by students in various countries across the globe to advance improved health programs for youth. However, in comparison to high-income countries, adolescents in low- and middle-income countries (LMICs) are generally at an early stage of understanding regarding physical activity (PA) and sedentary behavior (SB), often exhibiting low levels of PA and high levels of SB. Furthermore, there is limited evidence connecting PA and SB in school-going adolescents from LMICs.

Purpose

The objective of this review was to synthesize the available evidence regarding PA and sedentary behavior among school-going adolescents in LMICs using data from the GSHS.

Method

On March 18, 2023, a systematic literature search was performed across four electronic databases, namely Web of Science, PubMed, ScienceDirect, and EBSCO with n odaterestrictions. Studies were eligible if they: (1) utilization of data sourced from the Global Student-based Health Survey; (2) exploration of physical activity; (3) specific focus on adolescents; (4) conducted in low- and middle-income countries; (5) study design encompassing observational; (6) published as English journal articles.

Results

Among the 29 studies included in the analysis, the majority revealed elevated levels of sedentary behavior and diminished levels of PA in low- and middle-income countries. Furthermore, notable disparities in physical engagement and sedentary behavior were noted between male and female adolescents (p < 0.001). Augmented PA among teenagers was observed to correlate with higher consumption of vegetables and fruits (AOR = 1.30; 95% CI [1.13-1.50]; p < 0.001), decreased alcohol consumption, and a reduced prevalence of loneliness and depression (aOR 1.37, 95% CI [1.18-1.59]).

Conclusions

The results of this review affirm that in contrast to high-income countries, adolescents in low- and middle-income countries (LMICs) are in the early stages of comprehending physical activity, marked by low levels of PA. Physical activity and sedentary behavior in school-going adolescents from LMICs appear to be influenced by factors such as policies, cultural norms, socioeconomic conditions, as well as gender, and age.

Supporting adolescents' participation in muscle-strengthening physical activity: protocol for the 'Resistance Training for Teens' (RT4T) hybrid type III implementation-effectiveness trial

INTRODUCTION

In Australia, only 22% of male and 8% of female adolescents meet the muscle-strengthening physical activity guidelines, and few school-based interventions support participation in resistance training (RT). After promising findings from our effectiveness trial, we conducted a state-wide dissemination of the 'Resistance Training for Teens' (RT4T) intervention from 2015 to 2020. Despite high estimated reach, we found considerable variability in programme delivery and teachers reported numerous barriers to implementation. Supporting schools when they first adopt evidence-based programmes may strengthen programme fidelity, sustainability, and by extension, programme impact. However, the most effective implementation support model for RT4T is unclear.

OBJECTIVE

To compare the effects of three implementation support models on the reach (primary outcome), dose delivered, fidelity, sustainability, impact and cost of RT4T.

METHODS AND ANALYSIS

We will conduct a hybrid type III implementation-effectiveness trial involving grade 9 and 10 (aged 14-16 years) students from 90 secondary schools in New South Wales (NSW), Australia. Schools will be recruited across one cohort in 2023, stratified by school type, socioeconomic status and location, and randomised in a 1:1:1 ratio to receive one of the following levels of implementation support: (1) 'low' (training and resources), (2) 'moderate' (training and resources+external support) or 'high' (training and resources+external support+equipment). Training includes a teacher workshop related to RT4T programme content (theory and practical sessions) and the related resources. Additional support will be provided by trained project officers from five local health districts. Equipment will consist of a pack of semiportable RT equipment (ie, weighted bars, dumbbells, resistance bands and inverted pull up bar stands) valued at ~$A1000 per school. Study outcomes will be assessed at baseline (T0), 6 months (T1) and 18 months (T2). A range of quantitative (teacher logs, observations and teacher surveys) and qualitative (semistructured interviews with teachers) methods will be used to assess primary (reach) and secondary outcomes (dose delivered, fidelity, sustainability, impact and cost of RT4T). Quantitative analyses will use logistic mixed models for dichotomous outcomes, and ordinal or linear mixed effects regression models for continuous outcomes, with alpha levels set at p<0.025 for the outcomes and cost comparisons of the moderate and high support arms against the low support arm.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the University of Newcastle (H-2021-0418), the NSW Department of Education (SERAP:2022215), Hunter New England Human Research Ethics Committee (2023/ETH00052) and the Catholic Schools Office. The design, conduct and reporting will adhere to the Consolidated Standards of Reporting Trials statement, the Standards for Reporting Implementation Studies statement and the Template for Intervention Description and Replication checklist. Findings will be published in open access peer-reviewed journals, key stakeholders will be provided with a detailed report. We will support ongoing dissemination of RT4T in Australian schools via professional learning for teachers.

TRIAL REGISTRATION NUMBER

ACTRN12622000861752.

A scalable school-based intervention to increase early adolescents' motor competence and health-related fitness

Schools are key settings for the promotion of students' physical activity, fitness, and motor competence. The purpose of our study was to investigate the efficacy of a 5-month-long intervention program that aimed to increase students' motor competence and health-related fitness during school days. We conducted a quasi-experimental study with 325 Finnish Grade 5 (Mage  = 11.26, SD = 0.33) students from five schools. Two schools were allocated to the intervention group and three schools to the control group. The intervention consisted of three components: (a) weekly 20 min session during regular PE lessons, (b) weekly 20 min session during recess, and (c) daily 5-minute-long classroom activity breaks. All activities were designed to systematically develop different elements of motor competence and fitness. The following assessments were conducted at baseline and 5-months: cardiorespiratory fitness levels were measured by 20-meter shuttle run test, muscular fitness by curl-up and push-up tests, and motor competence by 5-leaps and throwing-catching combination tests. We analyzed the data using a multi-group latent change score modeling. Results showed that students in the intervention group developed significantly better in 20-meter shuttle run test (β = 0.269, p = 0.000, 95% CI [0.141, 0.397]; +5.0 laps), push-up (β = 0.442, p = 0.000, 95% CI [0.267, 0.617]; +6.5 repetitions), curl-up (β = 0.353, p = 0.001, 95% CI [0.154, 0.552]; +7.8 repetitions), and throwing-catching combination tests (β = 0.195, p = 0.019, 95% CI [0.033, 0.356]; +1.1 repetitions) than students in the control group. The intervention program appeared to be feasible and effective in increasing students' cardiorespiratory fitness, muscular fitness, and object control skills. This indicates that guided school-based physical activity programs can be influential in promoting physical fitness and motor competence among early adolescent students.

A Deep Learning Neural Network to Classify Obesity Risk in Portuguese Adolescents Based on Physical Fitness Levels and Body Mass Index Percentiles: Insights for National Health Policies

The increasing prevalence of overweight and obesity among adults is a risk factor for many chronic diseases and death. In addition, obesity among children and adolescents has reached unprecedented levels and studies show that obese children and adolescents are more likely to become obese adults. Therefore, both the prevention and treatment of obesity in adolescents are critical. This study aimed to develop an artificial intelligence (AI) neural network (NNET) model that identifies the risk of obesity in Portuguese adolescents based on their body mass index (BMI) percentiles and levels of physical fitness. Using datasets from the FITescola^® project, 654 adolescents aged between 10-19 years old, male: 334 (51%), female: n = 320 (49%), age 13.8 ± 2 years old, were selected to participate in a cross-sectional observational study. Physical fitness variables, age, and sex were used to identify the risk of obesity. The NNET had good accuracy (75%) and performance validation through the Receiver Operating Characteristic using the Area Under the Curve (ROC AUC = 64%) in identifying the risk of obesity in Portuguese adolescents based on the BMI percentiles. Correlations of moderate effect size were perceived for aerobic fitness (AF), upper limbs strength (ULS), and sprint time (ST), showing that some physical fitness variables contributed to the obesity risk of the adolescents. Our NNET presented a good accuracy (75%) and was validated with the K-Folds Cross-Validation (K-Folds CV) with good accuracy (71%) and ROC AUC (66%). According to the NNET, there was an increased risk of obesity linked to low physical fitness in Portuguese teenagers.

Efficacy of school-based interventions for improving muscular fitness outcomes in children: A systematic review and meta-analysis

The World Health Organization recommends that children should engage in an average of 60 min of moderate-to-vigorous physical activity (MVPA) per day and should perform activities that strengthen muscle and bone at least 3 days a week. Public health professionals as well as pediatric researchers have identified schools as a strategic place to promote muscular strength development. Thus, the aim of this systematic review and meta-analysis was to investigate the efficacy of school-based exercise interventions for improving muscular fitness (MF) in children. Searches were conducted in three databases. Eligible criteria were randomized and non-randomized controlled trials evaluating the effects of school-based exercise interventions on MF (i.e. muscular strength, muscular power, and local muscular endurance) in children under 13 years of age. Risk of bias by the National Institutes of Health tool was appraised, and pooled effect sizes (Hedges'g) were calculated using random-effects inverse-variance analyses. Seventeen studies enrolling 1653 children (28% girls were analyzed). Exercise interventions, mostly combined interventions targeting selected domains of MF, were associated with significant moderate increases in local muscular endurance (g = 0.65 95% CI, 0.13 to 1.17, p = 0.020; I²= 85.0%) and muscular strength and muscular power (g = 0.33 95% CI, 0.16 to 0.51, p = 0.001; I²= 59.3%), with higher effects using interventions with ≥3 sessions per week. Our findings indicate that school-based exercise that includes strength building exercises may improve MF in children and, consequently, prepare modern day youth for the demands of exercise and sport activities. HighlightsSchool-based muscle and bone strengthening exercises performed at least 3 days per week may serve to support the development of muscular fitness in girls and boysIntegrative interventions that include a variety of strength and conditioning activities seem to be a promising strategy to promote muscular fitness in school environmentFuture research should standardize assessment methods for use with children in the school context and should include interventions with girlsIt is of interest to a growing number of health care providers, fitness professionals and physical education teachers to encourage participation in well-designed muscle and bone strengthening exercises.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study

BACKGROUND

The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts.

OBJECTIVE

This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents.

METHODS

Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel.

RESULTS

There was strong between-panel agreement (panel 1: r_s = 0.76, p < 0.01; panel 2: r_s = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures".

CONCLUSIONS

The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

EFFECTS OF PROGRESSIVE LOAD TRAINING ON SPRINTERS’ CARDIORESPIRATORY ENDURANCE

ABSTRACT Introduction: The most evident change during exercise is the increase in oxygen demand, and prolonged high-intensity exercises may impact this even more on this demand. Physical training with progressive loads is a method that aims to reach the training goals by adjusting factors such as initial load, stage load, and a load of the athletes and can be a monitor of the aerobic and anaerobic exercise on the athlete with potential benefits for the high demand of oxygenation. Objective: Study the changes in heart rate and indexes of cardiorespiratory endurance of sprinters under training with progressive loads. Methods: By random sampling, the study subjects were 15 male sprinters and 15 non-sportsmen as research volunteers. The study subjects performed a protocol with progressive load training on a platform. All subjects underwent the Italian Kosmai cardiopulmonary function test before and after training. Results: The subjects who did not practice the sport showed VO2 max values at an exercise intensity of 13 km/h. The VO2 max maximum for sprinters was 15 km/h. Individuals who were not sprinters generally showed lower VT levels than sprinters (P <0.05). Average non-speeder individuals demonstrated higher MET scores than sprinters. Conclusion: Cardiopulmonary endurance and energy metabolism levels are strongly related to long-term participation in physical activity and exercise intensity. Incremental load training improved cardiorespiratory fitness in sprinters. The results may provide a specific theoretical basis for the daily training of sprinters in the future. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

A Trend Analysis of Adherence to the Muscle Strengthening Exercise Guidelines in US Adolescents

Objectives: This study aimed to describe the trends of the muscle-strengthening exercise (MSE) guidelines adherence in adolescents and factors associated with the adherence. Methods: Using the Youth Risk Behavioural Survey data, this study assessed the trends of adhering to the MSE guidelines in adolescents. The survey-year-based trends of MSE guidelines adherence was assessed with logistic regression. Binary logistic regression was used to identify the correlates (i.e., sex, grade, race/ethnicity) of the guidelines' adherence. Results: 73,074 study participants (female = 36,497, male = 36,108; mean age = 16.04 years) were included for analysis. An overall declining trend of the MSE guidelines in adolescents was found (55.6% in 2011 → 49.5% in 2019, p < 0.001), and similar trends were observed in both sexes. The declining trends varied by sociodemographic factors (e.g., grade). Boys and younger adolescents were more likely to adhere to the MSE guidelines. Conclusion: The declining trend of adhering to MSE guidelines in US adolescents would be a health concern in this population. Girls and older adolescents should be targeted as intervention priorities.

The Feasibility and Acceptability of an Online CPD Programme to Enhance PE Teachers' Knowledge of Muscular Fitness Activity

Schools provide an opportunity to enhance muscular fitness of English youth during physical education (PE). Continued professional development (CPD) among teachers may improve muscular fitness activity delivery in schools. This study sought to assess the feasibility and acceptability of an online CPD programme to enhance PE teachers' knowledge of muscular fitness activity.

METHODS

Co-production of an online CPD platform was undertaken with five secondary school PE teachers. A quasi-experimental pre-post control group design for the CPD was adopted (CPD group n = 76, control n = 32). Upon CPD completion feedback was solicited for qualitative analysis.

RESULTS

Pre-and-post CPD knowledge quiz data were available from 65 participants (55.4% male). The median knowledge quiz change score was significantly higher in the CPD group than in the wait list control group (CPD score vs. control score; U =37, z = -5.96, p < 0.01). Three primary themes reflecting factors associated with the acceptability and feasibility were (1) practical application, (2) support and resources, and (3) knowledge and confidence.

CONCLUSIONS

Co-production of an online CPD programme can improve knowledge and affect practice. PE teachers that completed the CPD reported the online platform was beneficial to overcoming the limitations of face-to-face CPD such as time and financial constraints and suggested the content covered was beneficial and appropriate to their teaching. Future work is required to establish links between teachers' learning following CPD, the translation into PE practice and student MF outcomes.

School-Based Comprehensive Strength Training Interventions to Improve Muscular Fitness and Perceived Physical Competence in Chinese Male Adolescents

Purpose. This research was to see how effective and feasible school-based comprehensive strength training programs are in improving muscular fitness and perceived physical competence in Chinese male adolescents. Methods. A total of 123 participants ( $13.46\pm 0.60$ years) were randomized to comprehensive strength training intervention group (CST) ( $n=62$ ) and the control group (CON) ( $n=61$ ). The training sessions were performed three times a week for ten weeks in CST. Muscular fitness (i.e., muscular strength, power, and muscular endurance) and perceived physical competence were assessed at initial testing and final testing. Results.The subjects in the CST significantly improved their mean performance in standing long jump ( $p<0.05$ ), vertical jump ( $p<0.05$ ), 1 min push-ups ( $p<0.05$ ), 1 min sit-ups ( $p<0.05$ ), handgrip strength ( $p<0.05$ ), and perceived physical competence ( $p<0.05$ ) after the intervention. Moreover, the CST were greater in standing long jump ( $p<0.05$ ), vertical jump ( $p<0.05$ ), 1 min sit-ups ( $p<0.05$ ), handgrip strength ( $p<0.05$ ), and perceived physical competence ( $p<0.05$ ) compared to the CON, but no in 1 min push-ups ( $p>0.05$ ). Conclusions. The comprehensive strength training interventions designed in this study can significantly increase male adolescents’ muscular fitness, especially in the lower extremity muscle power and abdominal core endurance, and can enhance their perceived physical competence.

'Walk Buds': A walking programme to increase physical activity, physical fitness and emotional wellbeing, in 9-13 yr old children with intellectual disability. A study protocol for a clustered RCT

BACKGROUND

Young people with intellectual disabilities are traditionally less physically fit compared to their non-disabled peers. While the health benefits of increasing physical activity are evident, there remains a lack of evidence on how to increase physical activity and reduce sedentary behaviour in young people with intellectual disabilities. Walking interventions, including those delivered in school settings, have been found to significantly increase physical activity levels of young people without disabilities. However, to date there has been a paucity of studies testing walking interventions for young people with intellectual disabilities in school settings. In an earlier study we developed the Walk Buds school-based walking programme for children with intellectual disability (aged 9-13 yrs), which incorporated a paired buddy component.

AIM

We plan to conduct a clustered feasibility RCT that will enable us to examine the acceptability of the Walk Buds programme, randomisation, and outcome measures, check the fidelity programme delivery, and identify the facilitators and barriers to the implementation of the programme.

METHODS

This study is a two-arm, cRCT feasibility trial where eight schools will be randomised into either an intervention arm (Walk Buds) or an 'exercise as usual' arm. We are aiming to recruit between 130 and 160 young people with intellectual disabilities. Outcome measures will be recorded at baseline and three-months post-intervention. A process evaluation will explore the factors that could impact on the internal and external validity of a future cRCT and the intervention's logic model.

DISCUSSION

Walk Buds is the first theoretically underpinned, peer-led, multi-component, manualised school-based walking programme that aims to increase physical activity, physical fitness, and emotional wellbeing in 9-13 yr old children with intellectual disabilities.

Longitudinal trends and predictors of muscle-strengthening activity guideline adherence among Canadian youths

OBJECTIVES

Muscle-strengthening activity (MSE e.g. push-ups, sit-ups, use of weight machines) is linked to multiple health benefits for youth, and is part of the global physical activity guidelines for children and adolescents (5-17 years). However, MSE is rarely assessed in youth health surveillance. This study describes the longitudinal trends and predictors of MSE among a cohort of Canadian youths.

DESIGN

Longitudinal.

METHODS

Data were drawn from a cohort of 3366 youths who participated in three waves of COMPASS, a longitudinal study of secondary school students across Canada [Wave 1 (T1) 2015/16, Wave 2 (T2) 2016/17, Wave 3 (T3) 2018/19]. The prevalence of the sample meeting the MSE guideline (≥3 days/week) was calculated for each wave. A multivariable logistic regression assessed the odds of meeting the MSE guideline for each wave (T1 and T2 and T3) across sociodemographic/lifestyle characteristics (e.g. sex, race, regionally, Body Mass Index, and aerobic physical activity).

RESULTS

For the total sample, MSE guideline adherence significantly declined across each study wave (T1 = 57.0%; T2 = 52.0%; T3 = 48.5%; p < 0.001 for linear trend). Population sub-groups less likely to meet the guideline at each wave included females, youth who were underweight or obese, those reporting insufficient aerobic physical activity, those from large urban settings, and youth who identify as Asian.

CONCLUSIONS

Among a large sample of Canadian youths, approximately half met the MSE guideline, with this prevalence declining over time. Large-scale MSE interventions are needed to address the low and decreasing adherence to this key modifiable health-related behavior among Canadian youths.

Evaluating the reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens program

BACKGROUND

Physical activity guidelines recommend young people engage in regular muscle-strengthening activities (e.g., resistance training [RT]). However, few school-based physical activity interventions have been delivered at-scale or promoted RT. The aim of this study was to evaluate the reach, effectiveness, adoption, implementation and maintenance of the Resistance Training for Teens (RT for Teens) program.

METHODS

Data were collected between August 2015 and October 2020. RE-AIM was operationalized as: (i) Reach: number and characteristics of students estimated to be exposed to the program; (ii) Effectiveness: impact of the program on student-level outcomes measured in a subsample of 750 students from 17 schools; (iii) Adoption: number and representativeness of schools with one or more teachers trained to deliver the program; (iv) Implementation: extent to which the program was delivered as intended; and (v) Maintenance: extent to which the program was sustained in schools.

RESULTS

The estimated program reach was ~ 10,000 students, out of a total student population of ~ 200,000 (~ 5%). Students were from diverse socioeconomic and ethnic backgrounds. Improvements in muscular fitness, RT self-efficacy, perceived cardiorespiratory fitness and flexibility, and participation in muscle-strengthening physical activities were documented. A total of 30 workshops were delivered, involving 468 teachers from 249 schools from diverse geographical regions. Implementation varied considerably, with teachers adapting the program to suit the context of their school and student cohorts. However, RT skill development and the promotion of muscular fitness were the session components delivered most during sessions. Teachers' adherence to the SAAFE (Supportive, Active, Autonomous, Fair and Enjoyable) teaching principles was high. Approximately 30% of teachers (144/476) registered to use the RT for Teens app. At the school-level, 37% (93/249) of schools had at least one registered user (teacher and/or student). A total of 2,336 workouts and 3,116 fitness tests were completed by registered users. Of the 249 schools represented, 51 (20.5%) sent an additional (previously untrained) teacher to a second workshop.

CONCLUSIONS

The RT for Teens program had broad reach and adoption. However, intervention delivery varied considerably across schools and additional support strategies are required to optimize intervention implementation and maintain program delivery over time. Future studies will benefit from the utilization of accepted frameworks, recommendations and guidelines for implementation research.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12621000352808), retrospectively registered 1^st February 2021.

"It's Just Not Something We Do at School". Adolescent Boys' Understanding, Perceptions, and Experiences of Muscular Fitness Activity

BACKGROUND

English youth typically do not sufficiently engage in the types and intensities of physical activity that develop muscular fitness. The aim of this study was to use a combination of qualitative techniques to explore adolescent boys' understanding, perceptions, and experiences of physical activity and the role muscular fitness plays within boys' physically active lifestyles.

METHODS

Focus group interviews with a write, draw, show, and tell activity were conducted with 32 adolescent boys aged 14-16 years from 3 secondary schools. Three separate sources of data (frequency counts, verbatim transcripts, and visual data) were generated and were pooled together and triangulated. Data were analysed deductively, first using the Youth Physical Activity Promotion model as a thematic framework, and then inductively.

RESULTS

Physical activity was frequently associated with organised sport, and most boys were unaware of current UK physical activity guidelines. Co-participation was frequently reported as a reinforcing factor to physical activity.

CONCLUSIONS

There was a perceived lack of opportunity to participate in muscular fitness activities, particularly in school, and knowledge of how to conduct muscular fitness activities was limited. The contribution of physical education was highlighted as being key to facilitating exposure to muscular fitness activities.

The SIMAC study: A randomized controlled trial to compare the effects of resistance training and aerobic training on the fitness and body composition of Colombian adolescents

The aim of this study was to evaluate the impact on muscle strength, aerobic fitness and body composition, of replacing the physical education (PE) class of Colombian adolescents with resistance or aerobic training. 120 tanner stage 3 adolescents attending a state school were randomized to resistance training, aerobic training, or a control group who continued to attend a weekly 2- hour PE class for 16 weeks. The resistance training and aerobic training groups participated in twice weekly supervised after-school exercise sessions of < 1 hour instead of their PE class. Sum of skinfolds, lean body mass (bioelectrical impedance analysis), muscular strength (6 repetition maximum (RM)) bench press, lateral pulldown and leg press) and estimated cardiorespiratory fitness (multistage 20 meter shuttle run) were assessed at pre and post intervention. Complete data were available for n = 40 of the resistance training group, n = 40 of the aerobic training group and n = 30 PE (controls). Resistance training attenuated increases in sum of skinfolds compared with controls (d = 0.27, [0.09-0.36]). We found no significant effect on lean body mass. Resistance training produced a positive effect on muscle strength compared with both controls (d = 0.66 [.49-.86]) and aerobic training (d = 0.55[0.28-0.67]). There was a positive effect of resistance training on cardiorespiratory fitness compared with controls (d = 0.04 [-0.10-0.12]) but not compared with aerobic training (d = 0.24 [0.10-0.36]). Replacing a 2-hour PE class with two 1 hour resistance training sessions attenuated gains in subcutaneous adiposity, and enhanced muscle strength and aerobic fitness development in Colombian youth, based on a median attendance of approximately 1 session a week. Further research to assess whether adequate stimuli for the development of muscular fitness exists within current physical education provision is warranted.

Effects of School-Based Physical Activity Programs on Health-Related Physical Fitness of Korean Adolescents: A Preliminary Study

As adolescents spend the majority of their time focused on exams and assignments, they do not have sufficient time to engage in physical activity; this lack of physical activity is an important public health concern. This study aimed to investigate how school-based physical activity programs affect the health-related physical fitness of adolescents in the Republic of Korea. For this study, a total of 120 high school students participated in a school-based physical activity program that included badminton and table tennis for 15 weeks each (35 min/day, three times a week), with a total of 30 weeks for one academic year. The parameters for health-related physical fitness measured muscle strength (handgrip strength), power (standing long jump), cardiorespiratory fitness (shuttle run test), flexibility (sit and reach), body mass index (BMI), and the total score. The results revealed a statistically significant improvement in muscle strength (p < 0.001), power (p < 0.001), cardiorespiratory fitness (p < 0.001), flexibility (p = 0.005), and the overall health-related physical fitness score (p = 0.001). However, students’ BMI showed no significant difference before and after participation (p = 0.825). The results of this study indicated that school-based physical activity programs can have a positive effect on the health-related physical fitness of adolescents.

Secular Trends in the Achievement of Physical Activity Guidelines: Indicator of Sustainability of Healthy Lifestyle in Czech Adolescents

(1) Background: The increasing socio-economic and educational demands on adolescents should be reflected in their lifestyles accordingly. The aim of the study was therefore to identify the trends in the achievement of physical activity (PA) guidelines by Czech adolescents through objective and subjective PA monitoring. (2) Methods: The research was carried out between 2010 and 2017 and involved 49 secondary schools, 2 higher vocational schools, and 8 universities in the Czech Republic. In total, the projects involved 1129 girls and 779 boys. PA monitoring was performed by Yamax SW-700 pedometers and IPAQ-long questionnaires. (3) Results: The results according to the average number of steps/day confirm a decrease in the amount of PA in boys and girls and in the achievement of the recommended 11,000 steps/day. However, the estimates of meeting the recommended weekly PA expressed as MET-min/week based on the IPAQ-long questionnaire are not so convincing about the decrease. (4) Conclusions: The combination of objective monitoring of weekly PA using wearables and subjective estimates of weekly PA using a questionnaire regarding the ease of application, appears to be a sufficient indicator of the status of and trend in PA and thus the sustainability of a healthy lifestyle in youths.