Resistance Training for Children and Adolescents

A Survey-Based Evaluation of Resistance Training Prescription Practices, Knowledge, and Attitudes Among Family Physicians

BACKGROUND

Despite the well-established benefits of resistance training (RT) in reducing health risks and enhancing quality of life, adherence to RT guidelines remains low. Promoting RT through healthcare practitioners could facilitate its widespread adoption. Although numerous studies have examined healthcare practitioners' knowledge and prescription practices of physical activity, few have specifically focused on RT.

METHODS

Prescription practices and barriers, knowledge and attitudes toward RT, and attitudes toward RT education were assessed from a convenience sample recruited by a multichannel approach (eg, social media and mailing lists). Physicians answered an online questionnaire composed of 32 questions developed by a multidisciplinary team. A convenience sample was recruited through social media and mailing lists.

RESULTS

A total of 158 family physicians practicing in Israel completed the questionnaire. RT prescription rates were low, ranging from 16.9% to 31.9%, depending on the estimation method. Self-reported barriers to RT prescription included insufficient knowledge about RT and how to prescribe it. Physicians showed limited knowledge of RT guidelines but generally viewed RT positively for various health conditions. Finally, 83.5% felt inadequately trained in RT, and 88.6% expressed a desire for further education.

CONCLUSIONS

This study highlights a gap between the recognized benefits of RT and the prescription practices and knowledge of family physicians. Enhanced educational efforts targeting RT could bridge this gap, potentially increasing RT prescription rates and improving public health outcomes.

The Era of Resistance Training as a Primary Form of Physical Activity for Physical Fitness and Health in Youth Has Come

Resistance training (RT) is widely regarded as the gold standard approach for enhancing muscular fitness (i.e., muscle strength, power, and muscular endurance) in youth while also providing health and physical fitness benefits traditionally associated with aerobic training (e.g., enhanced cardiorespiratory fitness, reduced body fat, improved insulin sensitivity). Additionally, while bone health can be improved following RT (particularly after plyometric jump training), aerobic training may result in a lesser or even neutral impact on bone mineral density enhancement (e.g., swimming). Regarding mental health and cognition, while aerobic training has well-established positive effects, preliminary evidence in obese youth suggests that RT may offer greater benefits in certain aspects compared to aerobic training. Additionally, RT can reduce the risk and incidence of injuries in youth. Overall, we argue in this Current Opinion article that the current consideration of RT as an additional, rather than essential (possibly even the most essential), aspect of physical activity in current national and international guidelines needs to be reconsidered. Overall, there is an urgent need to inform relevant stakeholders that, while aerobic activities remain essential, the next generation of physical activity guidelines should place greater emphasis on the particular importance of RT, providing more comprehensive guidance on its implementation for youth.

The effect of Stop X exercises on balance, strength and range of motion of male adolescent football players with dynamic knee valgus

Dynamic valgus of the lower limb is known as a risk factor associated with improper muscle function for many lower limb injuries, especially knee injuries. Stop X exercises has been designed to enhance spatial orientation, prediction, and attention; increase body stability and movement coordination; and teach the appropriate landing techniques. Therefore, the aim of the present study was to investigate the effect of Stop X exercises on the balance, strength and range of motion (ROM) of male adolescent football players with dynamic knee valgus (DKV). Thirty football players with DKV were selected purposefully and were randomly divided into two groups, control (n = 15) and training (n = 15). Stork tests, Y-balance test (YBT), goniometer, and digital dynamometer were used to evaluate static balance, dynamic balance, ROM, and hip abduction and external rotation strength, respectively. Analysis of variance (ANOVA) and dependent t-tests were used to compare the between and within group differences. After 8 weeks of Stop X exercises, values showed significant improvements in hip abduction (p = 0.005) and external rotation (p = 0.001) strength and ROM (p = 0.009), static balance (p = 0.006) and total score of YBT (p = 0.001). The findings of this study suggest that the STOP-X injury prevention program enhances hip abduction and external rotation strength, ROM, as well as static and dynamic balance in adolescent football players with DKV. Therefore, it is recommended that sports trainers incorporate STOP-X training into the regular exercise routines for adolescent football players to leverage these benefits.

Sex differences in physical activity dose-response effects on site-specific bone mineral density during childhood and adolescence

Physical activity (PA) serves as a modifiable determinant of bone mineral density (BMD). However, sex- and site-specific dose-response relationships remain poorly defined. Leveraging data from the National Health and Nutrition Examination Survey (NHANES 2011-2014), this cross-sectional study investigated sex-specific associations between accelerometer-derived PA (volume and intensity) and site-specific BMD in 2,659 children and adolescents aged 8-19 years. BMD assessment was conducted via dual-energy X-ray absorptiometry, and PA was quantified using monitor-independent movement summary units (MIMS). Linear and nonlinear analyses revealed distinct patterns: boys exhibited stronger linear associations between PA volume and BMD at weight-bearing sites (e.g., pelvis, arms, and legs; β = 0.003-0.004, P < 0.05), and girls demonstrated nonlinear thresholds (e.g., volume threshold: 15.0 × 103 MIMS/day). Both sexes had intensity-driven thresholds (~ 45-49 MIMS/min), with diminishing returns above these values (β = 0.010 in boys; stagnation in girls). Directional trends suggest the greater BMD gains per standard deviation (SD) increase in PA for boys compared with that for girls across most skeletal regions (e.g., total body less head: 0.131 SD vs. 0.106 SD for intensity). However, statistical significance (P < 0.05) was observed only for arm BMD responses. Mechanistic analyses highlighted the corresponding biomechanical principles, with weight-bearing regions showing stronger PA-BMD links than nonweight-bearing sites (e.g., spine). These findings underscore the importance of prioritizing high-intensity, weight-bearing activities, particularly for girls, to optimize skeletal health during growth. Public health strategies should focus on achieving, rather than exceeding, the identified daily 60 min intensity thresholds (~ 45-49 MIMS/min) through school- and community-based interventions.

Effects of 12-week integrative neuromuscular training on muscular fitness and sex differences in response to intervention in five- to six-year-old preschoolers

Objectives

This study examined the effects of a 12-week integrative neuromuscular training (INT) program on muscular fitness in male and female five- to six-year-old preschoolers.

Methods

Thirty preschoolers were randomly assigned to either an experimental group (EG; n = 15; age = 5.3 ± 0.5 years, body height = 115.3 ± 5.2 cm, body mass = 20.7 ± 2.6 kg) or a control group (CG; n = 15; age = 5.2 ± 0.4 years, body height = 118.5 ± 4.9 cm, body mass = 22.6 ± 2.7 kg) participating in a 12-week INT program and regular physical education classes three times per week, respectively. Upper extremity maximal strength (grip strength test) and power (tennis ball throwing test), core endurance strength (one-minute sit-up test), and lower extremity power (standing long jump test) were assessed at the baseline (T0), Week 6 (T6), and Week 12 (T12). Data were analyzed using an independent samples T-test and a two-way repeated-measures ANOVA.

Results

Significant interaction effects between the EG and CG were observed for grip strength, tennis ball throws, one-minute sit-ups, and standing long jumps (p < 0.001). Relative to the CG, the EG demonstrated significant improvements in all muscular fitness at T6 and T12 (p < 0.05). However, no significant interaction was found between the time and the sex (p > 0.05).

Conclusions

These findings suggested that a 12-week INT program can more effectively enhance the muscular fitness of 5-6-year-old preschoolers compared to regular physical education classes, serving as an effective and efficient supplement to physical education for this age group. Furthermore, there is no evidence of sex -specific differences in the development of muscular fitness among 5-6-year-old preschoolers under the INT program.

Secular trends in physical fitness and cardiovascular risks among Chinese college students: an analysis of five successive national surveys between 2000 and 2019

Background

With increasing concerns about early-onset cardiovascular diseases, it is essential to understand the distribution of cardiovascular health among young adults. This study aimed to characterize trends in physical fitness and the prevalence of overweight/obesity (OWOB), elevated blood pressure (EBP), and their comorbidity among Chinese college students from 2000 to 2019 and to analyze the changes in their associations and subgroup differences.

Methods

Data were extracted from five cycles of the Chinese National Survey on Students' Constitution and Health (2000-2019), including 241,710 college students aged 19-22. Physical fitness indicator (PFI) was computed using standardized z-scores of forced vital capacity, sit-and-reach, 50-m dash, standing long jump, muscle strength, and endurance running. OWOB was defined as a body mass index ≥25 kg/m2, and EBP as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg. Comorbidity was defined as the co-occurrence of OWOB and EBP. Mixed-effects logistic regression was used to analyze associations, and generalized linear mixed-effects models were applied to examine dose-response relationships.

Findings

The median of college students' PFI deteriorated continuously from -0.16 in 2000 to -1.99 in 2019, with boys experiencing a faster decline than girls. The prevalence of OWOB, EBP, and comorbidity increased significantly from 3.7%, 2.2%, and 0.3% in 2000 to 14.0%, 5.2%, and 1.8% in 2019, respectively, with boys exhibiting higher prevalence than girls. Decreasing PFI levels were significantly associated with the increasing prevalence of OWOB, EBP, and comorbidity, and such associations were strongest in 2019. L-shaped curves were observed for the relationships between PFI and the prevalence of OWOB, EBP, and comorbidity, with stronger associations in boys. Provincial population attributable fraction showed that when improving the PFI levels from low to middle-low or above, college students in Guizhou, Sichuan, and Yunnan provinces exhibited the most reductions in OWOB, EBP, and comorbidity.

Interpretation

Physical fitness among Chinese college students has significantly declined over the past two decades, accompanied by marked increases in the burden of cardiovascular risks. There is an urgent need to increase the focus on college students' health and establish a college-based physical examination system to assess their long-term cardiovascular function.

Funding

The present study was funded by National Key R&D Program of China (Grant No. 2024YFC2707901 to Yi Song), National Natural Science Foundation of China (Grant No. 82273654 to Yi Song), and Beijing Office for Education Sciences Planning (Grant No. BBAA22027 to Yi Song).

Evaluating the efficacy of integrated injury prevention strategy combined with education in adolescent badminton players with early sports specialisation: a randomised controlled trial protocol

In recent years, there has been growing concern about the high rate of injuries in adolescent players, particularly those who engage in early sports specialisation, and there is a need for more effective and integrated sports-specific strategies that can reduce the rate of injuries and improve physical performance in this population. The primary purpose of this study is to compare the efficacy of an integrated injury prevention strategy combined with education versus conventional approaches in reducing injury rates, improving parental and coach awareness and enhancing physical performance in adolescent badminton players with early sports specialisation. Participants will be randomly assigned to either the integrated injury prevention strategy combined with the education or conventional approach group. The study will be conducted over 6 months, with measurements taken at baseline, and 6 months. The primary outcome measures will include injury rates, parental and coach awareness and physical performance. The results of this study will help determine whether the integrated approach can reduce injury rates, improve parent and coach awareness and enhance physical performance. Additionally, the study will assess the cost-effectiveness of the integrated approach and the level of player satisfaction. In conclusion, the outcomes of this randomised controlled trial will be useful for creating better injury prevention strategies for this group of athletes. This intervention trial is prospectively registered with Clinical Trials Registry India (CTRI Number-CTRI/2024/12/078261).

Comparison of Acute Orthopaedic Injuries From Cardiovascular Versus Strength Exercise in Adolescents and Young Adults to the Emergency Department: An Analysis of the National Electronic Injury Surveillance System Database, 2018-2022

Background

Adolescents and young adults comprise a growing cohort at risk for exercise-related injuries. Recent studies compare the effects of cardiovascular and strength exercise on mental health, cardiovascular disease, and mortality; however, there remains a gap in the literature about acute injuries from these exercise types.

Hypothesis/Purpose

The purpose was to compare acute orthopaedic injuries sustained during cardiovascular exercise versus strength training in adolescents and young adults. A secondary aim was to compare the distribution of age, sex, and injury characteristics with the types of exercise. Finally, it was hypothesized that injuries would have increased throughout the previous 5 years.

Study Design

Descriptive epidemiology study.

Methods

This retrospective study used a National Electronic Injury Surveillance System (NEISS) query to identify patients aged 14 to 22 years with orthopaedic injuries due to exercise activities from 2018 to 2022. Injuries were attributed to cardiovascular exercise or strength training, which included weightlifting. Descriptive data were reported, and statistical comparisons were conducted via chi-square tests, Fisher exact tests, or linear regressions.

Results

The NEISS query identified 3105 cases. A total of 1474 (50.9%) cases were attributed to cardiovascular exercise and 1423 (49.1%) to strength training-including 1136 (39.2%) to weightlifting. Also, 48.4% of cardiovascular-related and 75.1% of strength-related injuries occurred in men. The number of patients with cardiovascular-related (b = -7.983; P = .013), strength-related (b = -15.05; P = .001), and weightlifting-related (b = -11.78; P = .004) injuries decreased with increasing age. Most injuries were sprains/strains (68.2% cardiovascular-related vs 50.4% strength-related). There were more upper extremity injuries during strength training (65.9%) than cardiovascular exercise (16.3%) (P < .001). No significant changes were observed in the annual number of injuries (b = -20.70; P = .442).

Conclusion

Thousands of adolescents and young adults are injured each year while exercising. Strength training injuries were more common in men, but cardiovascular exercise injuries were comparable between men and women. Young age was associated with higher injury rates from all exercise types. Cardiovascular and strength exercises were associated with different injury patterns. Future studies should consider longer periods and overall participation to compare the incidence between cardiovascular and strength exercise.

Reliability of the biceps curl test and proposed percentiles in schoolchildren living at moderate altitude in Peru

The biceps curl test is easy to apply, does not require expensive equipment, and its short execution time makes it feasible in school settings with limited resources. To verify the reliability of the biceps curl test in children and adolescents and to provide reference values according to chronological age and sex. A total of 1103 schoolchildren aged 6 to 17 years (500 boys and 603 girls) were evaluated. Weight and height were evaluated and Body Mass Index (BMI) and Tri Ponderal Index (TPI) were calculated. The right and left hand biceps curl was evaluated in 30 s. Children aged 6 to 11 years used a 1 kg dumbbell and those aged 12 to 17 years used a 2 kg dumbbell. Percentiles were calculated using the LMS method. The values of the relative Technical Error of Measurement (TEM%) of the biceps curl test of both hands ranged from 0.48 to 2.89%. The intraclass correlation coefficient (ICC) evidenced high values of 0.93 to 0.99. The Bland-Altman plot showed wide limits of agreement (-1.28 to 1.29 rep). These findings demonstrate that the test is reliable and consistent for use in pediatric populations and is suitable for different stages of physical development in school children. The values showed stability and wide limits of agreement. In addition, the proposed percentiles are useful to evaluate and monitor the strength endurance performance of both arms.

Isokinetic Strength Profiles Among Youth after Medial Patellofemoral Ligament Reconstruction

Background

Knee strength is a critical measure of successful rehabilitation following medial patellofemoral ligament reconstruction (MPFLR). Yet, strength outcomes of youth following MPFLR are not widely reported.

Hypothesis/Purpose

The primary purpose was to profile isokinetic strength outcomes by sex and age among youth following MPFLR. A secondary purpose was to determine the relationship between normalized isokinetic strength values and patient-reported outcome scores by age and sex. The hypotheses were that 1) males would demonstrate higher normalized strength, and that 2) a higher proportion of males would achieve ≥90% limb symmetry when compared to females.

Study Design

Cross-sectional.

Methods

At 6.9±2.1 months after MPFLR, 162 patients completed isokinetic assessment of knee extension (KE) and flexion (KF) strength at 180°/s and 300°/s on both limbs (uninvolved [UN], involved [INV]). Strength data and patient-reported outcome scores, including the International Knee Documentation Committee (IKDC) Subjective Knee Form and Pediatric Quality of Life Inventory (PedsQL) were extracted from electronic medical records. Descriptive statistics were used to categorize data by age (Pre-adolescent, Early Adolescent, Late Adolescent, Young Adult) and sex. Independent-samples t-tests and chi-square analyses were used to determine sex-based differences in strength. Multiple linear regression analyses were used to determine the relationship between strength and patient-reported function.

Results

Among Early Adolescents, males demonstrated higher normalized KE strength at 300°/s compared to females (UN: 1.27±0.3 vs. 1.07±0.3 [p=0.01]; INV: 1.07±0.2 vs. 0.92±0.3 [p=0.03]). Among Late Adolescents, males demonstrated higher INV limb strength for KE 180°/s (1.55±0.53 vs. 1.24±0.5; p=0.02), KE 300°/s (1.25±0.4 vs. 1.00±0.4; p=0.01), and KF 180°/s (0.98±0.4 vs. 0.82±0.3; p=0.05). A higher proportion of Late Adolescent and Young Adult males achieved ≥90% LSI compared to females (p=<0.01-0.04). Regression models estimating IKDC and PedsQL scores were significant with INV KE strength as an independent variable (p=0.01-0.03).

Conclusions

Males demonstrated higher normalized strength and symmetry compared to females following MPFLR. Higher INV KE strength was associated with higher patient-reported function.

Level of Evidence

2b.

The influence of resistance training on inflammatory markers, body composition and functional capacity in healthy older adults: A systematic review and meta-analysis

BACKGROUND

Older adults experience chronic inflammation, which is associated with health conditions such as sarcopenia, and resulting in reduced functional capacity. Resistance training (RT) is a beneficial intervention for improving health in the elderly.

OBJECTIVE

This study aimed to investigate the effect of RT on inflammatory biomarkers, body composition, and functional capacity in healthy adults aged 60 years and over. Additionally, this study conducted a meta-regression to investigate the moderating effect of exercise variables on inflammatory markers.

METHOD

Medline, PubMed, Web of Science, Cochrane Library, Embase, and Google Scholar were searched systematically until December 2023. Randomized controlled trials (RCTs) assessing the impact of RT on C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), body weight, BMI, fat percentage, fat mass, lean mass, leg extension strength and six-minute walk test (6-MWT) were included. Effect size was estimated by using the mean difference (MD) with 95 % confidence interval (CI).

RESULTS

Nineteen RTCs involving 728 participants were included. The results revealed that CRP levels significantly decreased following RT programs (MD:0.74, p= 0.008), while TNF-α (MD: 0.1, p= 0.95) and IL-6 (MD:0.27, p= 0.12) did not show significant changes. Additionally, RT enhanced leg extension strength and 6-MWT performance.

CONCLUSION

RT effectively reduces CRP concentrations and enhances functional capacity in healthy older adults. However, it does not have a significant impact on TNF-α and IL-6 levels. Future researches are needed to make a clear conclusion and understand the mechanisms underlying the effects of RT in healthy older adults.

REGISTRATION

The original protocol was registered (CRD42023487573) in PROSPERO database.

Children's Sprint and Jump Performance after Plyometric-Jump Training: A Systematic Review

The effect of plyometric jump training on children's jump and sprint performance remains unclear. To explore the effects of PJT on jump and sprint performance in children and to further analyze the influence of participant characteristics and training variables. A literature search was conducted in the PubMed, Web of Science, and SPORTDiscus databases. The included studies (n = 17) involved 587 children, with study sample sizes ranging from 9 to 44 participants. Overall, PJT improved children's vertical jump performance involving squat jump and countermovement jump (ES = 0.78, 95% confidence interval [CI] = 0.41-1.16, I² = 63%, p < 0.01; n = 474), standing long jump performance (ES = 0.56, CI = 0.3-0.83, I² = 26%, p < 0.0001; n = 414), and sprint performance involving 5 m to 30 m distances (ES = -0.41, CI = -0.61 to -0.22, I² = 0%, p < 0.01; n = 424). Subgroup analysis showed non-tapering strategies (ES = 0.92, n = 88) resulted in significant difference than tapering strategies (ES = 0.37, n = 336 np = 0.01). Meta-regression showed a positive correlation between the total number of training sessions and standing long jump performance improvement (p = 0.03). Two studies have a high risk of bias (RoB), and 15 studies have a moderate RoB (some concerns). The GRADE assessment indicated a very low to low robustness of the evidence. In conclusion, PJT can improve children's jump and sprint performance. Increasing the number of training sessions may lead to better standing long jump results. However, the low to very-low robustness of the currently available evidence precludes recommendations regarding PJT for improving children's neuromuscular performance.

Foundations of Pediatric Lifestyle Medicine

Background: Lifestyle medicine utilizes therapeutic interventions to prevent, treat, and reverse chronic diseases by promoting healthy habits. While extensively studied in adults, its application in pediatrics remains underexplored. Given that many chronic diseases originate in early life, establishing the foundations of Pediatric Lifestyle Medicine is essential. Methods: This paper presents a comprehensive literature review and clinical insights to assess the evidence supporting Pediatric Lifestyle Medicine and provide age-appropriate, evidence-based guidelines for children and adolescents. Results: Pediatric Lifestyle Medicine is an evidence-based healthcare discipline focused on promoting and maintaining children's health by encouraging healthy habits from an early age. This approach prevents chronic diseases, supports physical and emotional well-being, and fosters long-term quality of life. Findings show that applying its principles in childhood can prevent obesity, improve mental health, and aid in disease management, while also reducing the risk of adult-onset conditions and benefiting planetary health. Pediatric Lifestyle Medicine is based on six pillars: preventive nutrition, physical activity, sleep, stress management, positive social connections, and risk prevention, the last of which includes toxin avoidance and other childhood-specific risks, such as accident prevention and screen overuse. Conclusions: Pediatric Lifestyle Medicine provides a cost-effective, evidence-based framework for improving childhood health and preventing chronic conditions. Integrating these principles into pediatric care can foster lifelong health benefits, emphasizing the need for further research and implementation in medical education.

Intensive physical training in children with heritable connective tissue disorders is feasible and safe: a pilot study

PURPOSE

This pilot study assessed the feasibility, safety, and acceptability of a physical training program combined with parental meetings for children with heritable connective tissue disorders (HCTD), including Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and Ehlers-Danlos syndromes (EDS). Secondary, it aimed to explore preliminary observations regarding the program's impact on individual training goals and physical fitness, including aerobic and anaerobic capacity, strength, agility, pain, fatigue, and disability.

MATERIALS AND METHODS

The intervention comprised functional power training (FPT) and high-intensity interval training (HIIT) conducted three times a week over 12 weeks. Data on feasibility, safety, and acceptability were collected, along with preliminary observations on physical fitness performance.

RESULTS

The intervention was feasible and safe, with no serious adverse events reported. However, acceptability was limited, with a participation rate of 27.8%. Preliminary findings revealed that 80% of participants achieved their training goals, 75% improved their aerobic capacity, and 70% showed gains in strength and agility, alongside reported reductions in pain and fatigue.

CONCLUSION

This study highlights the potential benefits of tailored physical training for children with HCTD. Despite acceptability challenges, the intervention demonstrated feasibility and safety, providing a foundation for larger-scale effectiveness studies that include systematic feedback mechanisms to enhance participant engagement.

The optimal training intervention for improving the change of direction performance of adolescent team-sport athletes: a systematic review and network meta-analysis

Background

Due to the influence of growth, adolescent team-sport athletes have the need to improve their change of direction (COD) performance and reduce the risk of anterior cruciate ligament (ACL) injuries during COD. However, the optimal intervention for improving COD performance has not yet been determined.

Objective

To quantitatively assess the effects of diverse training interventions on COD performance.

Methods

A systematic search of five databases was conducted, adhering to the PRISMA guidelines. Randomized controlled trials that examined 10 distinct training interventions for COD performance in adolescent team-sport athletes were emphasized. Effect sizes were represented as standardized mean differences (SMD) with 95% credible intervals (CI). The Cochrane study risk assessment tool evaluated the risk of bias in the selected studies.

Results

Of the 36 studies analyzed, involving 1,125 participants. Eccentric overload training (EOT) (SMD = -2.06, 95% CI [-2.83 to -1.29]) emerged as the most effective training method for overall COD performance. Subgroup analysis shows that combined training (COM) (SMD = -2.14, 95% CI [-3.54 to -0.74]) was the best training intervention for COD performance with angles less than 90°. EOT (SMD = -2.84, 95% CI [-4.62 to -1.07]) also was two best training intervention for COD performance with angles greater than 90°.

Conclusions

The choice of training intervention should be determined based on the COD angle. When the COD angle exceeds 90° or is not restricted, EOT is the optimal intervention; however, this is not the case for angles below 90°. Further high-quality studies are needed in the future to validate these findings. Systematic review registration: PROSPERO CRD42024501819.

Utilizing physical educators to monitor muscular strength and neuromuscular control among children with varied recess time

Introduction

Inactivity levels among children are climbing at alarming rates, leading to a lack of physical activities that produce muscular strength (MusS) development, which in turn creates effective neuromuscular control (NC) development. Developing appropriate MusS during childhood decreases the chances of physical injuries and many chronic diseases such as type II diabetes and cancer, which leads to healthier, active future adults. The purpose of this study was to utilize the physical education setting to examine MusS and NC factors in the Fall and Spring (Time 1 to Time 2) of one school year in a predominately Hispanic sample of second-grade children who received 60 min or 20 min of daily recess.

Methods

This quasi-experimental pre-test/post-test study administered four MusS tests and one NC test to District 1 (N = 59) which received 60 min of recess daily (intervention), and District 2 (N = 49) which received one 20 min daily recess (control). ANCOVAs were run for group differences at Time 2 while controlling for Time 1.

Results

Intervention children significantly outperformed control children on the single leg 3-hop muscular strength test F(1,105) = 13.1, p < .001, n 2 = .05, and the neuromuscular control side-step test F(1,105) = 4.77, p = .03, n 2 = .04. Between group ANCOVAs controlling for body fat percentages showed the single leg 3-hop test remained significant between groups F(1,91) = 23.5, p < .001, n 2 = .09.

Discussion

Increased recess was shown to aid in improved lower body muscular strength and neuromuscular control among second grade children, even when controlling for body fat percentages. As 70% of American children are not participating in the recommended daily activity guidelines, and roughly 20% of American children are overweight, exploring movement opportunities for children and efficient means of monitoring MusS and NC is pivotal to future health and movement functions of children.

Are bodybuilding and cross-training practices dangerous for promoting orofacial injuries? A scoping review

Bodybuilding and cross-training exercises bring health benefits. However, orofacial injuries can occur during practice. This study aimed to map, analyze, interpret, and synthesize data from studies on the main orofacial injuries resulting from bodybuilding and cross-training practices. This scoping review followed the Joanna Briggs Institute and PRISMA-ScR methods, with high-sensitivity searches in PubMed, Web of Science, Scopus, ScienceDirect, Embase, Virtual Health Library and the Google Scholar. Original scientific articles published up to May 2024 were included, which evaluated the presence of self-reported or professionally diagnosed orofacial injuries by bodybuilding and cross-training practitioners aged 18 years or older. Literature reviews, editorials, and guidelines were excluded. Tables and figures were used to map and summarize the results. Out of 30.485 potentially eligible articles, four were included. The main orofacial injuries identified in both bodybuilding and cross-training practitioners were dental damage (n = 4), temporomandibular joint (TMJ) disorders (n = 3), and traumas to oral soft tissues (n = 2) and facial soft tissues (n = 2). Dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. Therefore, dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. However, further prospective studies with more in-depth methodological designs and fewer biases are necessary.

Child Soccer Players' Perceptions of Strength and Conditioning Training: A Multimethod Approach Using Write, Draw, Show and Tell

PURPOSE

The use of strength and conditioning training in childhood is a hot topic surrounded by myths and misconceptions. Despite scientific evidence supporting the safety and benefits of this training for children, the lack of representation of their voices poses a challenge in designing training programs that meet their specific needs and requirements.

METHODS

Children's views, experiences, and perceptions of strength and conditioning training were explored by Write, Draw, Show and Tell techniques. Sixteen grassroots soccer players aged 11-12 years took part in one of 3 focus groups exploring the topic. Data were analyzed following an inductive approach enabling themes to be explored and later deductive analyses using the Youth Physical Activity Promotion model to create pen profile diagrams.

RESULTS

Strength and conditioning were frequently associated with muscle growth, coordination, endurance, and rest. Enabling factors included autonomy, resilience, physical development, and training opportunities. Reinforcing factors included social support, social interference, coaches' communication, role models, and the ways of implementation.

CONCLUSIONS

Participants favor integrating strength and conditioning into their soccer training rather than conducting it as a separate session, which is reflected in their enjoyment. Nonetheless, children remain apprehensive about the potential effects of this type of training on their growth.

RETRAGAM: Resistance training based on gamification during physical education. Rationale and study protocol

Children's physical inactivity and increasing sedentary behaviour have become major public health concerns, with a concurrent decline in muscular fitness (MF) contributing to poor physical outcomes during childhood and adolescence, highlighting the importance of developing resistance training (RT) programs. Furthermore, several educational strategies such as gamification seem to increase students' motivation which can produce an increase in performance outcomes. This study describes the rationale and protocol of a school-based randomized controlled trial called "RETRAGAM" (REsistance TRAining based on GAMification). For this investigation, a total of ≃180 children (grades 5 and 6; 10-12 years of age) from 6 randomly selected schools in Valencia (Spain) will be enrolled for 8 weeks in one of the experimental groups: EG (15 min of RT Functional HIIT circuit program), EG + G (the same EG program but with a gamification approach) or CG (Control Group). Outcomes will include physical activity profile, MF, anthropometry and body composition, as well as the enjoyment and motivation during Physical Education (PE). An interactive app for digital devices will be used for gamified storytelling, earning points for personalized children's avatars, and implementing a flipped classroom learning model. We conclude that the RETRAGAM will provide information about the effectiveness and implementation of a school-based RT intervention during PE with and without gamification in students' MF, body composition, motivation and enjoyment.

Clinical outcome changes in sarcopenic obesity: a meta-analysis of exercise training methods

AIM

Assessing the effect of various forms of exercise training on patients with sarcopenic obesity.

METHODS

Two independent reviewers systematically searched English and Chinese databases (PubMed, Embase, Cochrane Library, Web of Science, CNKI) for randomized controlled trials on various exercise training effects in sarcopenic obesity patients until October 2023. Reference materials and grey literature were also included. Selected studies underwent screening, data extraction, and quality assessment. Meta-analysis was conducted using Review Manager 5.4 software.

RESULTS

A total of 8 studies were included in the final analysis. The Meta-analysis results indicated that resistance training (RT) significantly improved grip strength (MD = 3.85, 95%CI: 1.50 to 6.20, P < 0.01), percentage of body fat (MD = -2.96, 95%CI: -4.19 to -1.74, P < 0.01), walking speed (MD = 0.23, 95%CI: 0.01 to 0.46, P = 0.04), IGF-1(MD = 0.79, 95%CI: 0.05 to 1.52, P = 0.04) and knee extension strength (MD = 4.85, 95%CI: 1.97 to 7.72, P < 0.01). There was no statistically significant difference observed in weight (MD = -0.61, 95%CI: -4.06 to 2.84, P = 0.73). Aerobic training (AT) resulted in a significant reduction in weight among patients with SO (MD = -6.07, 95%CI: -9.89 to -2.25, P < 0.01), while no statistically significant differences were observed in other outcome measures. Mixed training (MT) significantly improved percentage of body fat (MD = -2.42, 95%CI: -3.58 to -1.26, P < 0.01), weight (MD = -4.40, 95%CI: -8.40 to -0.40, P = 0.03), IGF-1 (MD = 1.01, 95%CI: 0.45 to 1.56, P < 0.01), and walking speed (MD = 0.15, 95%CI: 0.04 to 0.26, P < 0.01). However, no statistically significant differences were observed in grip strength (MD = -0.70, 95%CI: -4.00 to 2.60, P = 0.68) and knee extension strength (MD = 1.73, 95%CI: -1.31 to 4.78, P = 0.26). RT, AT, and MT exercise could not significantly improve the level of serum IL-6 in patients with SO, and the difference was not statistically significant [MD = -0.01,95%CI:-0.27 to 0.24, P = 0.92].

CONCLUSION

Various exercise training methods have differing effects on muscle-reducing obesity treatment. Compared to aerobic training, resistance training, and mixed training may offer more pronounced improvements, enhancing physical functioning in sarcopenic obesity patients. This underscores the clinical significance of exercise intervention in treating muscle-reducing obesity, suggesting future studies explore exercise intervention's role and mechanism, particularly related to IGF-1, IL-6, and other cytokines.

Effects of static stretching and walking during inter-set intervals of resistance training on muscle fatigue of the quadriceps

Introduction

Inter-set rest intervals are essential to reduce muscle fatigue and increase the total amount of volume of resistance training. Static stretching and walking may increase muscle blood flow and promote recovery during inter-set rest intervals. Therefore, the purpose of this study was to investigate the effects of 20 seconds of static stretching and walking during inter-set rest intervals of leg extension exercises on the number of repetitions to exhaustion, total amount of volume, and flexibility of the quadriceps (joint range of motion and muscle hardness) in untrained healthy males.

Methods

Fourteen healthy, untrained men performed three different interventions (passive rest, static stretching, and walking) during inter-set rest intervals of a leg extension exercise with a 70% load of maximum muscle strength, in random order. The range of motion and muscle hardness of the quadriceps were measured before and immediately after all interventions using a goniometer and a portable muscle hardness meter. The number of repetitions to exhaustion and total amount of volume load (load × repetitions) of the leg extension exercise were assessed. Repeated two-way ANOVA and a Friedman test were used to analyze the variables.

Results

Range of motion and muscle hardness were increased after all interventions (both p < 0.05). There was no significant difference in the number of repetitions to exhaustion (p = 0.651) or total amount of volume load (p = 0.206) between interventions.

Discussion

These results indicated that static stretching and walking during inter-set rest intervals did not influence the change in flexibility and muscle fatigue of the leg extension exercise.

The additive effect of neuromuscular electrical stimulation and resistance training on muscle mass and strength

PURPOSE

To compare strength and muscle mass development between conventional resistance training (RT) and a combined resistance training with neuromuscular electrical stimulation group (RT + NMES).

METHODS

Searches of EBSCO, GoogleScholar, PubMed, and ResearchGate were conducted for studies that met the inclusion criteria of being a randomized controlled trial comparing RT in isolation with NMES and RT being done simultaneously. Effect sizes were calculated as the standard mean difference (SMD) and meta-analyses were computed using random effects models. Thirteen studies were included in the analyses.

RESULTS

When comparing strength gain, there was a favorable effect towards superimposed training (SMD: 0.31; 95% CI 0.13-0.49; p = 0.02; I2 = 73.05%) with similar results seen for muscle mass (SMD: 0.26; 95% CI 0.04-0.49; p = 0.02; I2 = 21.45%).

CONCLUSION

Use of NMES during RT results in greater gains in strength and muscle mass compared to RT performed in isolation. Incorporation of NMES into RT protocols may represent a more effective strategy to improve muscle strength and muscle mass. Future studies should explore whether use of NMES concurrently with RT may have additive effects on metabolic and/or cardiovascular health.

The Centering of Youth Voice in the Development of a Virtual, Instructor-Led Physical Activity Program

BACKGROUND

Providing youth the opportunity to express their attitudes toward and recommendations for improvement of a home-based physical activity (PA) program may help to improve engagement in virtual PA program activities. Youth voice is an often-overlooked component that may be necessary for understanding what contributes to low participation and may have important implications for long-term adherence.

PURPOSE

Informed by Self-Determination Theory, this study aimed to formatively evaluate home-based exercise videos, incorporating youth feedback for improvement in the development of the videos.

METHODS

Youth participated in four (8-minute) PA videos varying in type (strength; cardio; mindfulness; sports skill). Youth accessed the videos and answered open-ended questions via an online survey. Data were analyzed using qualitative content analysis to identify emerging themes in responses.

RESULTS

Sixty-eight K-12 youth in the United States (52% girls; 38% non-White; 55% in K-5 grade; 17% in 6-8 grade; 28% in 9-12 grade) participated in this study. Overall, 61.9% of affective responses were positive, with mindfulness rating the highest and strength the lowest. Children were satisfied with the video structure, enjoyed having an opportunity to move at home and reported liking the engaging instructors. Suggestions were also given related to modifying video length, adding modifications for varying fitness levels, adding more kid-like features, and providing incentives.

CONCLUSIONS

Youth recommendations may be used to create tailored adaptations and implementation supports for PA programs in the home. Findings from this study demonstrate that incorporating youth voice may be an important step toward increasing engagement in home-based PA programming.

Optimal exercise dose and type for improving sleep quality: a systematic review and network meta-analysis of RCTs

Background

A substantial amount of research has explored the intricate relationship between exercise and sleep quality, consistently confirming that exercise can effectively enhance sleep quality. Nevertheless, previous studies have yet to conclusively determine which specific exercise program is most efficacious in improving sleep quality. To address this gap, the present study systematically evaluated the differential effects of various types of exercise, as well as exercise dosages (including duration, intervention period, frequency, and intensity), on sleep outcomes using a network meta-analysis approach. This endeavor aims to provide evidence-based support for the development of scientifically effective exercise programs tailored to improve sleep quality.

Methods

Through the Web of Science, PubMed, Cochrane Library, Embase, and Scopus databases, we conducted a search for randomized controlled trials investigating the effects of exercise interventions on sleep, with a search cutoff date of April 30, 2024. We rigorously selected the literature according to the PICOS principle, and two independent researchers extracted the data. We would like to change this passage to: Bias risk assessment was conducted using the RevMan 5.4 software, and traditional meta-analysis and network meta-analysis were performed using Stata 17.0 software to generate forest plots, network evidence plots, and funnel plots. Furthermore, we adopted the surface under the cumulative ranking curve (SUCRA) to evaluate and rank the intervention effects of different exercise types and dosages on sleep quality. To verify the robustness of our study results, we performed a sensitivity analysis using the leave-one-out method.

Results

The study strictly adhered to the PRISMA guidelines and included 58 RCT papers with a total of 5,008 participants. The network meta-analysis revealed significant variations in the impact of exercise frequency on sleep outcomes when compared to the control group. Interventions of 1-2 times per week [SMD = -0.85, 95% CI (-1.43, -0.26)], 3 times per week [SMD = -0.45, 95% CI (-0.80, -0.11)], and 4 times per week [SMD = -1.09, 95% CI (-1.92, -0.26)] demonstrated the most notable effects. Interventions lasting ≤30 min and 60-65 min were significantly more effective than the control group, with ≤30 min proving significantly more effective than 40-55 min [SMD = 0.75, 95% CI (0.01, 1.49)]. Interventions lasting 9-10 weeks [SMD = -1.40, 95% CI (-2.37, -0.44)], 12-16 weeks [SMD = -0.55, 95% CI (-0.90, -0.20)], and ≥ 24 weeks [SMD = -0.71, 95% CI (-1.31, -0.10)] were all significantly more effective than the control group. Additionally, the 9-10 weeks intervention period was found to be significantly more effective than the 6-8 weeks period [SMD = -1.21, 95% CI (-2.37, -0.04)]. Furthermore, interventions of moderate intensity [SMD = -1.06, 95% CI (-1.52, -0.61)] and high intensity [SMD = -1.48, 95% CI (-2.55, -0.40)] exercise interventions yielded significantly greater benefits compared to the control group. Specifically, high intensity interventions [SMD = -1.97, 95% CI (-3.37, -0.56)] and moderate intensity [SMD = -1.55, 95% CI (-2.57, -0.54)] exercise interventions were found to be significantly more effective than moderate-high intensity interventions. In terms of exercise types, aerobic exercise [SMD = -0.56, 95% CI (-0.86, -0.27)], traditional Chinese exercises [SMD = -0.57, 95% CI (-0.97, -0.18)], and combined exercise [SMD = -0.99, 95% CI (-1.66, -0.32)] interventions all produced significant improvements compared to the control group. The study determined that the most effective combination of exercise prescription elements for enhancing sleep quality includes a frequency of 4 times per week (SUCRA = 84.7), a duration of ≤30 min (SUCRA = 92.2), a period of 9-10 weeks (SUCRA = 89.9), and high-intensity (SUCRA = 92.9) combined exercise (SUCRA = 82.7).

Conclusion

The current evidence indicates that combined exercise with a frequency of 4 times per week, a duration of ≤30 min, a period of 9-10 weeks, and high intensity is most effective for improving sleep quality. Nevertheless, due to the limited number of studies included, further research is needed to enhance the reliability of the findings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42024555428.

Swim, Strength, or Combined Programs: Effect on Health-Related Physical Fitness in Adolescents With Down Syndrome

The adolescent population with Down syndrome (DS) appears to show higher levels of body fat and lower levels of cardiorespiratory fitness or muscle strength than their peers without disabilities. There is a need to create physical activity programs to improve these data. The aim of this research was to determine the effects of a 16-week swimming program, strength program, and combined program (swimming and strength training) on body composition and health-related physical fitness on adolescents with DS and to assess whether there are differences in the results of the different training programs. Forty-five adolescents (17 female and 28 male; average age 15.5 [1.53] years) with DS were recruited and randomized to three groups (swim [n = 15], strength [n = 15], and combined [n = 15]). Results showed that the swim group had significant improvements in all health-related physical fitness variables and there was an improvement in some body-composition variables (p < .05). The strength and combined groups obtained minor improvements in the variables analyzed. In summary, a 16-week swim program consisting of three sessions of 60 min is able to improve levels of body composition and health-related physical fitness in adolescents with DS. The swim training program seems to be more effective in improving body composition and health-related physical fitness than the strength or combined program. These findings could be useful in different special-education centers due to the predisposition shown by the population with DS to this sport modality.

Motor unit firing rates increase in prepubescent youth following linear periodization resistance exercise training

PURPOSE

The purpose was to examine the effects of 8-weeks (3 days/week) of linear periodization resistance exercise training (RET) on neuromuscular function in prepubescent youth.

METHODS

Twenty-five healthy prepubescent youth (11 males, 14 females, age = 9.1 ± 0.8 years) completed the RET (n = 17) or served as controls (CON, n = 8). Isometric maximal voluntary contractions (MVCs) and trapezoidal submaximal contractions at 35 and 60% MVC of the right leg extensors were performed with surface electromyography (EMG) recorded from the leg extensors [vastus lateralis (VL), rectus femoris, and vastus medialis] and flexors (biceps femoris and semitendinosus). EMG amplitude of the leg extensors and flexors were calculated during the MVCs. Motor unit (MU) action potential trains were decomposed from the surface EMG of the VL for the 35 and 60% MVCs. MU firing rates and action potential amplitudes were regressed against recruitment threshold with the y-intercepts and slopes calculated for each contraction. Total leg extensor muscle cross-sectional area (CSA) was collected using ultrasound images. ANOVA models were used to examine potential differences.

RESULTS

Isometric strength increased post-RET (P = 0.006) with no changes in leg extensor and flexor EMG amplitude. Furthermore, there were no changes in total CSA or the MU action potential amplitude vs. recruitment threshold relationships. However, there were increases in the firing rates of the higher-threshold MUs post-RET as indicated with greater y-intercepts (P = 0.003) from the 60% MVC and less negative slope (P = 0.004) of the firing rates vs. recruitment threshold relationships at 35% MVC.

CONCLUSIONS

MU adaptations contribute to strength increases following RET in prepubescent youth.

Cross-country adaptation and feasibility of an evidence-based resistance training intervention in the school setting

Background

Physical activity that strengthens muscles and bones at least three times per week are recommended, but few adolescents meet this target. The aim of our study was to adapt and evaluate the feasibility and preliminary efficacy of the Resistance Training for Teens (RT4T) program in Danish lower secondary schools.

Methods

Developed and evaluated in Australia, the aim of RT4T is to provide adolescents with competence, confidence, knowledge, and motivation to participate in resistance training. Translation and adaptation were based on the PRACTIS-guide and involved workshops with physical education teachers. Three 7th-grade classes and three 9th-grade classes were recruited for the feasibility study and followed the program over eight weeks. Participants completed a push-up test, a standing long jump test, and a beep-test before and after the intervention. In addition, they completed a survey about their self-efficacy, motivation, and resistance training competency. Four qualitative interviews were performed with participants and their physical education teachers.

Results

The participating teachers were motivated for the program, but they had difficulties providing students with appropriate feedback. Students were motivated by the equipment, games, and their improvements in fitness, but motivation declined during the program. A total of 57 students completed the physical tests and answered the survey. Resistance training self-efficacy improved significantly, while most other measures improved over time, without reaching significance.

Conclusion

Overall, the RT4T was acceptable and feasible in lower secondary schools in Denmark, but adjustments need to be made to increase the reach and efficacy of the program.

2024 SIAC guidelines on cardiorespiratory rehabilitation in pediatric patients with congenital heart disease

The 2024 Interamerican Society of Cardiology (SIAC) guidelines on cardiorespiratory rehabilitation (CRR) in pediatric patients with congenital heart disease aim to gather and evaluate all relevant evidence available on the topic to unify criteria and promote the implementation of CRR programs in this population in Latin America and other parts of the world. Currently, there is no unified CRR model for the pediatric population. Consequently, our goal was to create these CRR guidelines adapted to the characteristics of congenital heart disease and the physiology of this population, as well as to the realities of Latin America. These guidelines are designed to serve as a support for health care workers involved in the care of this patient group who wish to implement a CRR program in their workplace. The guidelines include an easily reproducible program model that can be implemented in any center. The members of this Task Force were selected by the SIAC on behalf of health care workers dedicated to the care of pediatric patients with congenital heart disease. To draft the document, the selected experts performed a thorough review of the published evidence.

Sex-specific associations of muscular fitness with overall academic performance and specific school subjects in adolescents: the EHDLA study

Introduction

Overalll, muscular fitness and academic performance are two variables widely studied in the literature. However, evidence on the relationship between muscular fitness and specific school subjects (e.g., physical education), as well as their differences by sex, is scarce.

Objective

The aim of this study was to examine the associations between muscular fitness and overall academic performance and between muscular fitness and specific subjects (i.e., language, math, foreign language, and physical education) in a sample of secondary Spanish school students.

Methods

For the present study, a sample of 766 students (45% boys, aged 12-17 years). From the Eating Healthy and Daily Life Activities (EHDLA) study was used. The Assessing the Levels of Physical Activity and Fitness (ALPHA-FIT) battery was used to determine handgrip strength and lower body muscular strength. The performance of the different school subjects was provided by the school centers.

Results

Overall, for both boys and girls, higher muscular fitness was associated with greater academic results, with the greatest differences in physical education. However, only significant differences were identified for girls.

Discussion and conclusion

Global muscular fitness is important for contributing to cognitive development, both in physical education and in the rest of the subjects of the educational curriculum for adolescents. At the same time, although the association appears to follow the same trend for both sexes, the results seem more evident for girls.

Synergistic effect of functional strength training and cognitive intervention on gross motor function in children with cerebral palsy

BACKGROUND

Cerebral palsy (CP) is a posture and movement disorder, however; it often includes disturbance of different aspects of cognitive function. This study aimed to investigate if combined functional strength training (FST) and cognitive intervention are more effective than either of them alone on gross motor function in children with spastic diplegic CP.

METHODS

Sixty-four children with spastic diplegic CP, with ages ranging from 8 to 12 years, were assigned randomly into four treatment groups; Group I; FST, group II; cognitive training, group III; combined FST and cognitive training, group IV; conventional physical therapy. The Gross Motor Function Measure (GMFM-88) was used to assess gross motor function at baseline, post-treatment, and 6 months follow-up.

RESULTS

Group III achieved a significant improvement in GMFM-88 when compared to other groups post-treatment and at follow-up.

CONCLUSION

This study suggests that combined lower limb FST and cognitive intervention had the potential to produce significantly more favorable effects than the single use of either of them on gross motor function in children with spastic diplegia.

Effects of non-pharmacological interventions for adults with subjective cognitive decline: a network meta-analysis and component network meta-analysis

BACKGROUND

Non-pharmacological interventions have a myriad of available intervention options and contain multiple components. Whether specific components of non-pharmacological interventions or combinations are superior to others remains unclear. The main aim of this study is to compare the effects of different combinations of non-pharmacological interventions and their specific components on health-related outcomes in adults with subjective cognitive decline.

METHODS

PubMed, Embase, Cochrane, CINAHL, PsycINFO, CENTRAL, Web of Science, and China's two largest databases, CNKI and Wanfang, were searched from inception to 22nd, January 2023. Randomized controlled trials using non-pharmacological interventions and reporting health outcomes in adults with subjective cognitive decline were included. Two independent reviewers screened studies, extracted data, and assessed risk of bias. Component network meta-analysis was conducted employing an additive component model for network meta-analysis. This study followed the PRISMA reporting guideline and the PRISMA checklist is presented in Additional file 2.

RESULTS

A total of 39 trials with 2959 patients were included (range of mean ages, 58.79-77.41 years). Resistance exercise might be the optimal intervention for reducing memory complaints in adults with subjective cognitive decline; the surface under the cumulative ranking p score was 0.888, followed by balance exercise (p = 0.859), aerobic exercise (p = 0.832), and cognitive interventions (p = 0.618). Music therapy, cognitive training, transcranial direct current stimulation, mindfulness therapy, and balance exercises might be the most effective intervention components for improving global cognitive function (iSMD, 0.83; 95% CI, 0.36 to 1.29), language (iSMD, 0.31; 95% CI, 0.24 to 0.38), ability to perform activities of daily living (iSMD, 0.55; 95% CI, 0.21 to 0.89), physical health (iSMD, 3.29; 95% CI, 2.57 to 4.00), and anxiety relief (iSMD, 0.71; 95% CI, 0.26 to 1.16), respectively.

CONCLUSIONS

The form of physical activity performed appears to be more beneficial than cognitive interventions in reducing subjective memory complaints for adults with subjective cognitive decline, and this difference was reflected in resistance, aerobic, and balance exercises. Randomized clinical trials with high-quality and large-scale are warranted to validate the findings.

TRIAL REGISTRATION

PROSPERO registry number. CRD42022355363.

Changes in Muscle Mass and Strength in Adolescents Following High-Intensity Functional Training with Bodyweight Resistance Exercises in Physical Education Lessons

(1) Background: The growing prevalence of obesity, diabetes, hypertension, and declining physical fitness among children and adolescents due to sedentary lifestyles has increased attention toward preventive intervention to tackle this issue. This study investigated the age-related effects of high-intensity functional training (HIFT), based on bodyweight resistance exercises conducted during physical education lessons, on muscle mass and strength improvement. (2) Methods: Adolescent males (n = 116) were allocated to four HIFT experimental groups (EGs) and four standard physical education program control groups (CGs) according to age (15, 16, 17, and 18 years [y]). The changes in muscle mass (absolute and relative to height [SMI]), hand-grip strength (HGS), sit-ups (SUs), and standing broad jump (SBJ) were analyzed using two-way analysis of variance (ANOVA) with Bonferroni tests. (3) Results: HIFT significantly increased muscle mass and scores in all strength tests (p < 0.01), while chronological age was significant for HGS (p < 0.01). Interactions between HIFT and chronological age categories were observed for HGS (p = 0.01) and SBJ (p < 0.03). Detailed post hoc tests revealed improvement in muscle mass across all chronological age categories for both approaches (p < 0.05). The 18y-EG group improved HGS over their control peers (p < 0.01), the EG groups significantly improved their SU results (p < 0.01), and SBJ improved in the 15y-EG and 18y-EG groups compared to their control (p < 0.01). (4) Conclusions: This research highlights the effectiveness of a school-based HIFT program in promoting muscle mass gains and enhancing muscle strength among adolescents. The findings offer valuable insights for implementing bodyweight exercises during physical education classes.

Understanding the importance of peak bone mass

Bone mass attained early in life is one of the most important determinants of lifelong skeletal health. Bone mineral content increases exponentially during childhood. In fact, 40%-60% of the total adult bone mass is accrued during puberty. By the end of the first 2 decades of life, peak bone mass has been reached. Between ages 20-50, bone mass has plateaued, but it continues to remodel. This is regulated by parathyroid hormone (PTH), vitamin D3, and insulin-like growth factor 1 (IGF-1). After the age of 50, bone mass begins to decrease. The purpose of this paper is to review the importance of maximizing peak bone mass and factors that can modify and maintain peak bone mass.

Key Concepts

(1)Peak bone mass is attained by the end of the second decade of life.(2)There are more fractures during peak height velocity in adolescence as the body increases in size but bone mineralization lags behind.(3)The risk of adult osteoporosis starts in childhood.(4)There are modifiable and nonmodifiable risk factors that affect peak bone mass.

Level of Evidence

IV.

A comparison of the effects of two protocols of concurrent resistance and aerobic training on physical fitness in middle school students

Objective

This study aimed to compare the effects of two concurrent training (CT) protocols on the physical fitness of middle school students.

Method

A 12-week quasi-experimental pre-test/post-test study was conducted with 157 middle school students (age = 12.48 ± 0.34, n = 90 females) divided into three groups: CT group A (CT-0h) received combined resistance training (RT) and aerobic training (AT) in each physical education session, CT group B (CT-48h) received RT and AT across two separate physical education classes 48 h apart, and a control group (Con) received no training. Training occurred twice a week. Test indicators included cardiorespiratory fitness (CRF) measured by estimated VO2max and 20 m shuttle run (laps), as well as muscle strength assessed through long jump, vertical jump, and handgrip strength.

Results

The intervention groups exhibited significant increases in estimated VO2max and muscle strength compared to their baseline values (p < 0.05). Both CT-0h and CT-48h groups demonstrated significant improvements in 20 m shuttle run (laps) (mean difference: 8.88 laps, p < 0.01; mean difference: 4.81 laps, p < 0.01, respectively), standing long jump (mean difference: 6.20 cm, p < 0.01; mean difference: 3.68 cm, p < 0.01, respectively), vertical jump (mean difference: 4.95 cm, p < 0.01; mean difference: 4.04 cm, p < 0.01, respectively), and handgrip strength (mean difference: 11.17 kg, p < 0.01; mean difference: 6.99 kg, p < 0.01, respectively). CT-0h group exhibited significantly increased estimated VO2max (mean difference: 1.47 ml/kg/min, p < 0.01) compared to the CT-48h group.

Conclusion

Both CT programs effectively improved adolescents' physical fitness indicators. However, the program that integrated RT and AT within the same physical education class demonstrated superior enhancement in adolescents' CRF.

Physical Activity in Cerebral Palsy: A Current State Study

This document analyzes a survey conducted in three geographical areas in Spain, focusing on centers for individuals with cerebral palsy (CP). The study aims to determine the adherence rate to recommended physical activity guidelines, assess if there is a decline in interest in physical activity over time, identify the stage at which this decline occurs, and explore potential mechanisms, tools, or strategies to sustain long-term engagement in regular physical activity for this population. The 36-item questionnaire comprises multiple-choice, open-ended, and Likert scale-type questions. Data were collected on physical activity frequency and duration, daily living activities, and demographics. Statistical analysis identified patterns and relationships between variables. Findings reveal that only a 17.6% meets the World Health Organization (WHO) recommendations regarding regular physical activity (RPA), decreasing in frequency or number of days a week, (3.7 d/w to 2.9 d/w; p < 0.01) and duration (50.5 min/d to 45.2 min/d; p < 0.001) with age, especially for those with higher Gross Motor Function Classification System (GMFCS) mobility levels. Obesity slightly correlates with session duration (ρ = -0.207; p < 0.05), not mobility limitations. Gender has no significant impact on mobility, communication, or physical activity, while age affects variables such as body mass index (BMI) and engagement (p < 0.01). A substantial proportion follows regular physical activities based on health professionals' advice, with interest decreasing with age. To improve adherence, focusing on sports-oriented goals, group sessions, and games is recommended. These findings emphasize the importance of personalized programs, particularly for older individuals and those with greater mobility limitations.

Effects of a home-based exercise combined yoga and resistance training in enthesitis-related arthritis in China: study protocol for a randomised controlled trial

INTRODUCTION

Enthesitis-related arthritis (ERA) is a category of juvenile idiopathic arthritis (JIA). The complications of JIA include pain, muscle weakness, limited movement and worsening quality of life. Yoga is an effective exercise therapy for rheumatoid arthritis and may have similar benefits for JIA. Considering the limitation of yoga for strengthening muscles, combined yoga and resistance training (CYRT) may compensate for the shortcomings and provide more benefits for JIA patients. Despite this, there is currently a lack of studies investigating the effectiveness of CYRT for JIA patients. Due to the inaccessibility of traditional exercise therapy, home-based exercise is needed. The study aims to assess the effectiveness of home-based CYRT on JIA.

METHODS AND ANALYSIS

This is a 12-week randomised single-blind controlled trial study. 60 patients with ERA will be randomised into two groups: the home-based exercise group (HBE) and the health education (HE) group. The HBE group (n=30) will perform the CYRT programme 3 times a week at home for 12 weeks and receive HE. The HE group (n=30) will only receive HE. The outcomes include primary outcome (pain levels) and secondary outcomes (lower limb muscle strength, motion range of joint, aerobic fitness, function ability, fatigue levels, mental health, quality of life and blood biomarkers). The assessments will be conducted at baseline, postintervention (12 weeks) and follow-up (24 weeks). Data will be analysed by intention to treat.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine in December 2023 (approval no. XHEC-C-2023-059-3). This study will require informed consent from all subjects and guardians of children under 18 years of age. The findings will be published in a peer-reviewed journal and international conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2300073446.

Resistance Exercise Training in Individuals With and Without Cardiovascular Disease: 2023 Update: A Scientific Statement From the American Heart Association

Resistance training not only can improve or maintain muscle mass and strength, but also has favorable physiological and clinical effects on cardiovascular disease and risk factors. This scientific statement is an update of the previous (2007) American Heart Association scientific statement regarding resistance training and cardiovascular disease. Since 2007, accumulating evidence suggests resistance training is a safe and effective approach for improving cardiovascular health in adults with and without cardiovascular disease. This scientific statement summarizes the benefits of resistance training alone or in combination with aerobic training for improving traditional and nontraditional cardiovascular disease risk factors. We also address the utility of resistance training for promoting cardiovascular health in varied healthy and clinical populations. Because less than one-third of US adults report participating in the recommended 2 days per week of resistance training activities, this scientific statement provides practical strategies for the promotion and prescription of resistance training.

Factors Involved in Higher Knee Extension Torque Induced by Repetitive Peripheral Magnetic Stimulation

OBJECTIVE

The study aimed to determine the relationship between knee extension torque induced by repetitive peripheral magnetic stimulation and the characteristics of the participants.

DESIGN

This was a basic study with noninvasive intervention. Knee extension torque induced by repetitive peripheral magnetic stimulation (repetitive peripheral magnetic stimulation-induced torque) and maximum voluntary contraction were measured. Stepwise method of multiple regression was performed to determine the factors affecting repetitive peripheral magnetic stimulation-induced torque at 100% intensity and repetitive peripheral magnetic stimulation-induced torque divided by maximum voluntary contraction (percent maximum voluntary contraction). Subcutaneous fat thickness, vastus lateralis muscle thickness measured by ultrasound, maximum voluntary contraction, and mean power frequency of electromyography during maximum voluntary contraction were selected as independent variables.

RESULTS

Repetitive peripheral magnetic stimulation was applied to the right vastus lateralis of 30 young healthy adults (average age, 21.1 ± 0.3 yrs). In the multiple regression analysis, repetitive peripheral magnetic stimulation-induced torque ( P < 0.001) was shown to be independently and significantly associated with maximum voluntary contraction (β = 0.510), subcutaneous fat thickness (β = -0.358), and vastus lateralis muscle thickness (β = 0.208), while percent maximum voluntary contraction value ( P < 0.05) was independently and significantly associated with vastus lateralis muscle thickness (β = 1.059).

CONCLUSIONS

Repetitive peripheral magnetic stimulation-induced torque decreases with thicker subcutaneous fat and increases with stronger maximum voluntary contraction or with thicker muscle.

Combined aerobic and muscle-strengthening activity guidelines and their association with obesity in US adolescents

Most of the evidence on physical activity for maintaining a healthy weight in adolescents is based solely on aerobic physical activity alone, with little attention given to the muscle strength component. This study aimed to investigate the associations between aerobic activities and muscle-strengthening activities (MSA) and overweight/obesity among a representative sample of adolescents. Data from the United States-based Youth Risk Behavior Surveillance System for the 2011-2019 cycle were used in this cross-sectional study. Adolescents self-reported their adherence to aerobic and MSA guidelines, as well as their height and weight. Overweight and obesity were defined using the age- and sex-specific criteria of the Centers for Disease Control and Prevention, with a body mass index (BMI) ≥85th and ≥95th percentiles, respectively. We examined the associations between adherence to physical activity guidelines (reference: not meeting either of the physical activity guidelines) and overweight/obesity or obesity using binary logistic regressions. These analyses were adjusted for race/ethnicity, sex, age, screen time, sleep duration, tobacco, alcohol, fruit, vegetables, and soda consumption. A total of 42 829 adolescents (48.98% girls) were included in the study. Of these, 22.23% met both guidelines for physical activity, 30.47% had overweight/obesity, and 14.51% had obesity. Compared with meeting neither guideline, meeting both aerobic and MSA guidelines was associated with lower odds of having overweight/obesity (odds ratio [OR] = 0.64, 95% confidence interval [CI], 0.60 to 0.68) and obesity (OR = 0.52, 95% CI 0.48 to 0.56). These results were consistent across years of assessment, sex, and race/ethnicity. In conclusion, our results highlight the importance of MSA, which is often overlooked in physical activity recommendations in many studies, in combating childhood obesity in the United States.

Independent and joint associations of aerobic and muscle-strengthening exercise with mental health in adolescents: A cross-sectional analysis before and during COVID-19 using the 2015-2021 National Youth Risk Behavior Survey

PURPOSE

COVID-19 led to social isolation that may have compromised adolescent mental health. This study examined the independent and joint associations of aerobic physical activity (PA) and muscle-strengthening exercise (MSE) with mental health problems in adolescents.

METHODS

Participants were US adolescents who completed the 2015-2021 National Youth Risk Behavior Survey (N = 61,298; 45.7% female). Data were collected between 2015 and 2021 and analyzed in 2023. Outcomes were binary response items asking about feeling sad/hopeless, having difficulty concentrating, remembering, or making decisions, and having a suicidal ideation. Preventive exposure variables were items asking about frequencies of aerobic PA and MSE with responses dichotomized to align with recommendations. Independent and joint associations were examined using robust Poisson regression with covariates selected using double selection lasso. Structural equation models examined the associations treating PA and MSE as continuous predictors and poor mental health as a latent dependent variable.

RESULTS

Meeting either recommendation alone associated with a 4-10% lower prevalence of mental health problems (APR = 0.90-0.96, p < 0.05), and meeting both recommendations associated with a 15%-20% lower prevalence of mental health problems (APR = 0.80-0.85, p < 0.001). Although categorical joint associations were stronger in males (p < 0.05), multiplicative interactions were observed in females using continuous variables for PA and MSE (β = -0.09, p < 0.001).

CONCLUSION

Meeting aerobic PA and MSE recommendations associated with lower prevalence of mental health problems. Participation in MSE below recommended levels may be beneficial for females when combined with aerobic PA. Future research should examine these associations by acquiring contextual information and device-based assessments.

May the Force Be with Youth: Foundational Strength for Lifelong Development

ABSTRACT

Today's youth are weaker than previous generations, and measurable reductions in physical fitness are beginning to emerge. Without targeted initiatives that recognize the foundational importance of resistance training, weaker children and adolescents may be more likely to experience the inevitable consequences of neuromuscular dysfunction and less likely to experience the pleiotropic benefits of exercise and sport. Early exposure to strength-building activities is needed to prepare today's youth for ongoing participation in varied physical activities throughout this developmental phase of life. The novel iceberg of physical development is a metaphoric image that illustrates the sequential and cumulative influence of muscular strength on motor skills and physical abilities. Efforts to enhance the physical capacity of youth should include resistive skills that improve basic movement patterns and enhance motoric competence. A shift in our conceptual thinking about youth resistance training is needed to alter the current trajectory toward physical inactivity and related comorbidities.

"Eat more protein, build more muscle": A grounded theory study of muscle-building behaviors among Canadian adolescents and young adults

Unique risk factors for the development of muscle dissatisfaction and engagement in muscle-building behaviors have been described by theoretical frameworks and supported by empirical research. What remains unknown are the unique processes, including catalysts and facilitators, which underpin engagement in muscle-building behaviors. Therefore, this study used a grounded theory methodology to elucidate the process of engagement in muscle-building behaviors. Thirty-three individual semi-structured interviews with Canadian adolescents and young adults ages 16-30 years were conducted. Transcripts were analyzed using initial and focused coding to identify themes that explained the grounded theory. The core theme underpinning the grounded theory was balancing aesthetic, health, and functional goals in relation to participants' engagement in muscle-building behaviors. Participants described experiences that encompassed several unique phases of muscle-building engagement, including the initiation phase, beginner phase, preservation phase, and intensification phase. Participants also described unique methods of gathering information on muscle-building behaviors, and their own analysis and decision-making processes driving their behaviors. Findings from this study extend prior theory and research by conceptualizing a novel process theory of engagement in muscle-building behaviors among adolescent and young adults, resulting in important implications for research and practice.

Effects of Resistance Training on Academic Outcomes in School-Aged Youth: A Systematic Review and Meta-Analysis

BACKGROUND

The primary aim of our systematic review and meta-analysis was to investigate the effect of resistance training on academic outcomes in school-aged youth.

METHODS

We conducted a systematic search of six electronic databases (CINAHL Complete, PsycINFO, SCOPUS, Ovid MEDLINE, SPORTDiscus and EMBASE) with no date restrictions. Studies were eligible if they: (a) included school-aged youth (5-18 years), and (b) examined the effect of resistance training on academic outcomes (i.e., cognitive function, academic achievement, and/or on-task behaviour in the classroom). Risk of bias was assessed using the appropriate Cochrane Risk of Bias Tools, funnel plots and Egger's regression asymmetry tests. A structural equation modelling approach was used to conduct the meta-analysis.

RESULTS

Fifty-three studies were included in our systematic review. Participation in resistance training (ten studies with 53 effect sizes) had a small positive effect on the overall cognitive, academic and on-task behaviours in school-aged youth (standardized mean difference (SMD) 0.19, 95% confidence interval (CI) 0.05-0.32). Resistance training was more effective (SMD 0.26, 95% CI 0.10-0.42) than concurrent training, i.e., the combination of resistance training and aerobic training (SMD 0.11, 95% CI - 0.05-0.28). An additional 43 studies (including 211 effect sizes) examined the association between muscular fitness and cognition or academic achievement, also yielding a positive relationship (SMD 0.13, 95% CI 0.10-0.16).

CONCLUSION

This review provides preliminary evidence that resistance training may improve cognitive function, academic performance, and on-task behaviours in school-aged youth.

PROSPERO REGISTRATION

CRD42020175695.

Association between the use of muscle-building supplements and DNA damage in resistance training practitioners

OBJECTIVES

Little is known about the relationship between the supplements used for sport and safety, especially regarding the induction of genotoxicity. Therefore, more knowledge about a DNA damage possibly caused using sport supplements is necessary. The aim of this study was to investigate the potential association between the use of muscle-building supplements and DNA damage in resistance training practitioners.

METHODS

Muscle-building supplements were classified into three categories based on evidence of efficacy and safety: Strong Evidence to Support Efficacy and Apparently Safe (SESEAS); Limited or Mixed Evidence to Support Efficacy (LMESE), and Little to No Evidence to Support Efficacy and/or Safety (LNESES). DNA damage was evaluated by the comet assay (DNA damage index and frequency) and buccal micronucleus by the cytome assay (micronuclei and nuclear buds). In the sequence, the adjusted analysis of covariance was performed. This study included 307 individuals ages 37.99 ± 13.95 y (52.1% men), of which 157 consumed supplements.

RESULTS

The results of the comet assay revealed that participants who used supplements had higher DNA damage indexes (P = 0.018) and damage frequency (P = 0.045) than those who reported using no supplements. Moreover, the comet assay also indicated that the participants who used supplements classified into the SESEAS category presented the highest DNA damage index (P = 0.025) and frequency (P = 0.044) compared with those who used no supplements. However, we found no significant difference in the micronuclei and nuclear buds in the evaluated groups (P > 0.05).

CONCLUSION

Supplement use is not associated with permanent damage, suggesting that SESEAS supplements are safe for consumption.

Anterior Cruciate Ligament Rehabilitation for the 10- to 18-Year-Old Adolescent Athlete: Practice Guidelines Based on International Delphi Consensus

Background

There are 2 treatment options for adolescent athletes with anterior cruciate ligament (ACL) injuries-rehabilitation alone (nonsurgical treatment) or ACL reconstruction plus rehabilitation. However, there is no clear consensus on how to include strength and neuromuscular training during each phase of rehabilitation.

Purpose

To develop a practical consensus for adolescent ACL rehabilitation to help provide care to this age group using an international Delphi panel.

Study Design

Consensus statement.

Methods

A 3-round online international Delphi consensus study was conducted. A mix of open and closed literature-based statements were formulated and sent out to an international panel of 20 ACL rehabilitation experts. Statements were divided into 3 domains as follows: (1) nonsurgical rehabilitation; (2) prehabilitation; and (3) postoperative rehabilitation. Consensus was defined as 70% agreement between panel members.

Results

Panel members agreed that rehabilitation should consist of 3 criterion-based phases, with continued injury prevention serving as a fourth phase. They also reached a consensus on rehabilitation being different for 10- to 16-year-olds compared with 17- and 18-year-olds, with a need to distinguish between prepubertal (Tanner stage 1) and mid- to postpubertal (Tanner stages 2-5) athletes. The panel members reached a consensus on the following topics: educational topics during rehabilitation; psychological interventions during rehabilitation; additional consultation of the orthopaedic surgeon; duration of postoperative rehabilitation; exercises during phase 1 of nonsurgical and postoperative rehabilitation; criteria for progression from phase 1 to phase 2; resistance training during phase 2; jumping exercises during phase 2; criteria for progression from phase 2 to phase 3; and criteria for return to sports (RTS). The most notable differences in recommendations for prepubertal compared with mid- to postpubertal athletes were described for resistance training and RTS criteria.

Conclusion

Together with available evidence, this international Delphi statement provides a framework based on expert consensus and describes a practice guideline for adolescent ACL rehabilitation, which can be used in day-to-day practice. This is an important step toward reducing practice inconsistencies, improving the quality of rehabilitation after adolescent ACL injuries, and closing the evidence-practice gap while waiting for further studies to provide clarity.

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.

Building for the Future: A Systematic Review of the Effects of Eccentric Resistance Training on Measures of Physical Performance in Youth Athletes

BACKGROUND

Eccentric resistance training is recognised as an effective stimulus for enhancing measures of muscular strength and power in adult populations; however, its value in youth athletes is currently not well understood.

OBJECTIVE

The aim of this systematic review was to critically appraise the effects of eccentric resistance training on measures of physical performance (i.e. muscular strength, jump, sprint and change of direction) in youth athletes 18 years of age and under.

METHODS

Original journal articles published between 1950 and June 2022 were retrieved from electronic search engines of PubMed, SPORTDiscus and Google Scholar's advanced search option. Full journal articles investigating the acute and chronic effects of eccentric resistance training on measures of physical performance in youth athletes (i.e. a person 18 years of age or under who competes in sport) were included. The methodological quality and bias of each study were assessed prior to data extraction using a modified Downs and Black checklist.

RESULTS

The search yielded 749 studies, of which 436 were duplicates. Three-hundred studies were excluded based upon title and abstract review and a further 5 studies were removed following the modified Downs and Black checklist. An additional 14 studies were identified during backward screening. Accordingly, 22 studies were included in our systematic review. The Nordic hamstring exercise and flywheel inertial training were the most frequently used eccentric resistance training methods in youth athletes. Improvements in physical performance following the Nordic hamstring exercise are dependent upon an increase in the breakpoint angle, rather than training volume (sets and repetitions), and are further elevated with the addition of hip extension exercises or high-speed running. A minimum of 3 familiarisation trials is necessary to elicit meaningful adaptations following flywheel inertial training. Furthermore, an emphasis should be placed upon decelerating the rotating flywheel during the final one to two thirds of the eccentric phase, rather than gradually throughout the entire eccentric phase.

CONCLUSIONS

The findings of this systematic review support the inclusion of eccentric resistance training in youth athletes to improve measures of muscular strength, jump, sprint and change of direction performance. The current eccentric resistance training methods are predominantly limited to the Nordic hamstring exercise and flywheel inertial training; however, the efficacy of accentuated eccentric loading to improve jump performance warrants attention in future investigations.

Conservative management of hand impairment in children and adolescents with heritable disorders of connective tissue: A scoping review

AIMS

To synthesize and critically appraise available interventions in the conservative management of hand impairment for children and adolescents with heritable disorders of connective tissue (HDCT).

METHODS

A search of peer-reviewed literature and online platforms were included with data regarding hand impairment and function, conservative management and outcome measures extracted and appraised. Levels of evidence were applied to published literature.

RESULTS

Ten peer-reviewed papers, eleven webpages and YouTube videos met the inclusion criteria. Reported interventions included: strengthening, orthoses, assistive equipment, education and pacing. Evidence of intervention effectiveness and evidence-based guidance on dosage were absent, with no consistency of outcome measures monitoring intervention effectiveness. Online platforms posted by health professionals predominantly provided advice for families without clinical detail of interventions.

CONCLUSIONS

There is a consistent suite of interventions identified in both peer-reviewed literature and online platforms used by clinicians and families to manage hand impairment for children and adolescents with HDCT. Clear dosage parameters and outcome measures are needed in future intervention studies to determine the effectiveness of interventions and guide clinicians in how best to treat hand impairment. Increasing accountability and quality of online resources posted by health professionals for families is warranted to ensure dosage details and precautions are provided.

School-Based Circuit Training Intervention Improves Local Muscular Endurance in Primary School Students: A Randomized Controlled Trial

BACKGROUND

This study aimed to explore the effectiveness of a 12-week circuit training program in improving local muscular endurance in normal-weighted primary school students.

METHODS

The study involved a parallel-group randomized trial with 606 primary school boys assigned to an experimental or a control group. The participants underwent a 12-week circuit training program that involved multi-joint, total-body workouts using body weight, resistance bands, and medicine ball exercises. The study measured the participants' local muscular endurance during sit-ups, dynamic trunk extensions on a Roman bench (DTE), and push-ups.

RESULTS

After adjusting for the baseline, the treatment-grade interaction was significant for sit-ups (F = 7.74, p < 0.001, η_p² = 0.04), DTE (F = 6.49, p < 0.001, η_p² = 0.03), and push-ups (F = 9.22, p < 0.001, η_p² = 0.05), where the experimental treatment was more beneficial than the control. The treatment effect seemed to vary depending on the individual's baseline local muscle endurance capacity. As the baseline local muscular endurance values increased, the treatment and grade effects became less beneficial.

CONCLUSION

A 12-week circuit training program involving body weight, resistance bands, and medicine ball exercises suits school-based programs and can improve local muscular endurance in normal-weighted primary school boys. The experimental treatment was more effective than the control, and the individual baseline muscular endurance should be considered when designing training programs.

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.