What is the effect of resistance training on the strength, body composition and psychosocial status of overweight and obese children and adolescents? A Systematic review and meta-analysis

Effects of Functional Strength Training Combined with Aerobic Training on Body Composition, Physical Fitness, and Movement Quality in Obese Adolescents

This study aimed to compare the effects of 12 weeks of functional strength training combined with aerobic training (TG) and traditional resistance training combined with aerobic training (CG) on the body composition, physical fitness, and movement quality of obese adolescents. Forty participants were randomly assigned to either the TG group (n = 20) or the CG group (n = 20). Each group underwent training five times per week, lasting 120 min each time, over a total period of 12 weeks. All participants followed a strict dietary program. Anthropometric parameters, body composition, physical fitness, and movement quality were evaluated at baseline and after intervention. A two-way repeated measures ANOVA observed a significant interaction between time and group for body mass (p = 0.043), body fat percentage (p = 0.045), body mass index (p = 0.025), neck circumference (p = 0.01), chest circumference (p = 0.027), left-hand grip strength (p = 0.043), right-hand grip strength (p = 0.048), standing broad jump (p = 0.044), and total Functional Movement Screen score (p = 0.003), and the improvement was greater for TG in comparison to CG. TG was found to be more effective than CG in enhancing body composition, physical fitness, and movement quality in obese adolescents.

Comparison of Metabolic Risk Factors Based on the Type of Physical Activity in Korean Adolescents: Results from a Nationwide Population-Based Survey

BACKGROUND

Physical activity (PA) is associated with a favorable metabolic risk profile in adults. However, its role in adolescents remains unclear. In this study, using data (2019-2021) from the 8th Korea National Health and Nutrition Examination Survey, we investigated the optimal exercise type for preventing metabolic complications in adolescents.

METHODS

A total of 1,222 eligible adolescent participants (12-18-year-old) were divided into four groups as follows: aerobic exercise (AE), resistance exercise (RE), combined aerobic and resistance exercise (CE), and no exercise (NE). Daily PA was assessed using the international PA questionnaire. Blood samples were collected to measure lipid, glucose, and insulin levels. Additionally, the homeostasis model assessment for insulin resistance (HOMA-IR) and triglyceride-glucose (TyG) indices were measured. Multivariate regression analysis was used to compare the metabolic risk factors across the PA groups before and after propensity score matching (PSM) adjustment for confounding variables.

RESULTS

The CE group exhibited improved fasting glucose levels, lower TyG index, reduced white blood cell count, and higher high-density lipoprotein (HDL) cholesterol levels than the NE group. The RE group exhibited lower mean blood pressure, triglyceride, fasting insulin, HOMA-IR, TyG index and a reduced risk of metabolic syndrome than the NE group. The AE group had higher total and HDL cholesterol levels. In detailed comparison of the AE and RE groups, the RE group consistently exhibited favorable metabolic parameters, including lower blood pressure and total and low-density cholesterol levels, which persisted after PSM.

CONCLUSION

These findings highlight the positive effects of PA on cardiovascular risk factors in adolescents. Thus, RE may have a more favorable metabolic effect than AE. Further studies are needed to validate the benefits of exercise according to the exercise type.

Physical activity interventions among youth living in rural and remote areas: A systematic review

OBJECTIVES

Physical activity (PA) interventions have potential to improve health and social outcomes among youth. The aim of this study was to collate the evidence on the effectiveness of PA and sports-based interventions among youth living in rural and remote areas.

METHODS

We searched five databases and grey literature (HealthInfoNet). Search terms included PA, rural status, adolescents, and outcome measures. Studies were included if published in English, recruited 10- to 18-year olds, and were based in rural or remote communities (Modified Monash Model [MMM] area classification range of MMM 3-7). Quasi-experimental and pre-experimental and post-experimental PA interventions were included. Two authors evaluated the articles independently following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, and relevant data were extracted. International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020199001).

RESULTS

Of the 11802 studies identified, 6 were included in the review. Most studies were excluded for not meeting MMM 3-7 criteria. Four of the included studies had sports-related interventions, and 2 had walking-based interventions. Outcomes included self-efficacy, mental health, and academic performance. One study reported a positive effect of PA on self-efficacy (β = 0.26, p=0.018, odds ratio = 1.43 [95% confidence interval: 1.07-1.92]).

CONCLUSION

Few community-based PA interventions have been evaluated in rural areas. There is a need for future evaluations in rural areas and include PA as an outcome measure.

IMPLICATIONS FOR PUBLIC HEALTH

The findings highlight the need for measurement of PA outcomes in PA interventions in rural and remote areas. The findings also highlight the need for research to utilise a standardised measure of rurality.

Associations among metabolic health, weight status, and various physical fitness components in Japanese adolescents: a cross-sectional study (NICE EVIDENCE study- Agano 3)

Aim was to examine associations among metabolic health, weight status, and various physical fitness (PF) components in 1744 Japanese adolescents aged 13-14. Anthropometric measurements and PF tests (20 m shuttle run test [20mSRT], handgrip strength/body mass [HG], standing long jump [SLJ], and sit ups [SU]) were administered. The bottom sex-specific quintile of PF indicated "low fit". Participants were classified as non-overweight (non-OW) or overweight/obese (OW) according to the International Obesity Task Force. Clustered metabolic risk was defined as the sum of Z scores for mean arterial pressure, non-high-density lipoprotein cholesterol, and HbA1c, divided by three, and ≥ 1 SD. Combination of weight status and scores for HG or SU were additively associated with clustered metabolic risk. Compared with the non-OW-moderate-high fit group, the OW-low HG group was 3.05 (95%CI: 1.88-4.97) times more likely to have clustered metabolic risk although risk was not significantly elevated in the OW-moderate-high HG group (1.52 [95%CI: 0.88-2.62]). A similar association was observed between OW and low SU scores but not between OW and low 20mSRT or SLJ scores. Adolescents with OW and moderate-high HG or SU scores had a lower prevalence of an unfavourable metabolic state than those with OW and low HG or SU results.

Effects of different exercise modalities and intensities on body composition in overweight and obese children and adolescents: a systematic review and network meta-analysis

Introduction: Childhood and adolescent overweight and obesity are global public health issues. Previous studies on exercise and overweight and obese children have produced inconsistent findings and lacked comparisons between different exercise modalities and intensities. Therefore, a network meta-analysis is necessary to provide evidence-based intervention programs. This study aims to identify the effects of different exercise modalities and intensities on changes in body composition in overweight and obese children and adolescents. Methods: A search for randomized controlled trials was conducted on Web of Science, PubMed, Scopus, and Embase involving exercise interventions aimed at improving body composition (body fat percentage, BMI, fat mass, fat-free mass, body weight) in overweight and obese children and adolescents. A random effects network meta-analysis was performed using STATA 14.0 software within a frequentist framework. The literature quality was assessed using the Cochrane Risk of Bias Tool 2.0. Results: Thirty-two papers involving 1,452 participants were included. There were six types of intervention involved in the study, including moderate intensity aerobic exercise, high-intensity aerobic exercise, moderate intensity resistance exercise, high-intensity resistance exercise, moderate intensity combined exercise, and high-intensity combined exercise. The network meta-analysis results revealed that high-intensity combined exercise was the best exercise mode for improving BMI [mean difference in kg/m² = -1.65, 95% CI (-3.27, -0.02)] and reducing fat mass [mean difference in kg = -2.87, 95% CI (-4.84, -0.91)]. Moderate intensity combined exercise was the best mode for weight loss [mean difference in kg = -4.58, 95% CI (-5.94, -3.22)] and improvement in body fat percentage [mean difference in% = -2.52, 95% CI (-3.83, -1.20)]. High-intensity resistance exercise had the optimal effect in increasing fat-free mass [mean difference in kg = 1.10, 95% CI (0.22, 1.99)]. Conclusion: In conclusion, the study found that combined exercise, whether moderate or high intensity, was more effective than any other exercise modality in improving body fat percentage and BMI, reducing fat mass and weight. Resistance exercise was the most effective in increasing fat-free mass.

Associations of muscle-strengthening exercise with overweight, obesity, and depressive symptoms in adolescents: Findings from 2019 Youth Risk Behavior Surveillance system

Background

Previous studies have focused on the opposite relation between muscle strength, obesity, and depression in adults. Moreover, the evidence has indicated that obesity and depression in adults might be significantly decreased with Muscle Strength Exercise (MSE) albeit it might be insufficient. Therefore, the current study aimed to investigate the association between MSE, adiposity, and depression among United States adolescents.

Materials and methods

This cross-sectional study used the Youth Risk Behavioral Survey (YRBS) data. In YRBS, a cluster sample was used, and the investigation was divided into three stages. The study surveyed 13,677 high school students and conducted self-reported questionnaires on sex, grade, race/ethnicity, MSE days, overweight, obesity, and depressive symptoms. The study got the nationally representative population of American students in Grade 9 to 12 (around 12–18 years).

Results

A total of 13,677 participants (female = 6,885, male = 6641) were included in the final analysis. The participants meeting the guidelines’ requirements seemed more likely to be obese than those not meeting (OR = 1.28, 95% CI = 1.06–1.55). There was no statistical significance in the relations between the MSE guidelines and overweight and depression (OR = 0.86, 95% CI = 0.73–1.01: OR = 0.94, 95% CI = 0.83–1.06). For all the participants, the prevalence of those conforming to MSE was 30.1%. One-fifth of the participants reported no MSE per week, 7.8% reported 3 days of MSE per week, and 7.7% reported 7 days.

Conclusion

The main finding of this study indicated a positive relationship between the normative MSE required in guidelines and low-level obesity. Beyond that, the evidence was insufficient to confirm the positive links between MSE and depression among American adolescents. Our study could offer evidence for future MSE interventions in adolescents.

Effects of Strength Training on Body Fat in Children and Adolescents with Overweight and Obesity: A Systematic Review with Meta-Analysis

Childhood overweight and obesity represent a growing public health problem worldwide. Since the 1980s, the global prevalence of overweight and obesity in childhood and adolescence has increased by 47%. The promotion of exercise is an important intervention to reduce the physical damage of obesity. The meta-analysis was conducted in accordance with the general guidelines for the reporting of systematic reviews and meta-analyses (PRISMA). The PubMed, SciELO, ScienceDirect and Google Scholar databases were searched from August to December 2021. The search yielded 722 titles published between 2000 and 2021. After screening the titles and abstracts, 64 duplicate articles were detected, and 27 articles were ultimately included in the systematic review, including 26 articles published in English and one published in Spanish. There was a statistically significant effect of the strength training interventions on the percentage of body fat, Test of 0 i = (p = 0.00, z = 6.92), Test of 0 = (p = 0.00, Q (9) = 42.63). The findings reveal that strength training has a positive impact on the treatment of body fat in children and adolescents with overweight and obesity.

Concurrent Training Promotes Greater Gains on Body Composition and Components of Physical Fitness Than Single-Mode Training (Endurance or Resistance) in Youth With Obesity

The prevalence of obesity in the pediatric population has become a major public health issue. Indeed, the dramatic increase of this epidemic causes multiple and harmful consequences, Physical activity, particularly physical exercise, remains to be the cornerstone of interventions against childhood obesity. Given the conflicting findings with reference to the relevant literature addressing the effects of exercise on adiposity and physical fitness outcomes in obese children and adolescents, the effect of duration-matched concurrent training (CT) [50% resistance (RT) and 50% high-intensity-interval-training (HIIT)] on body composition and physical fitness in obese youth remains to be elucidated. Thus, the purpose of this study was to examine the effects of 9-weeks of CT compared to RT or HIIT alone, on body composition and selected physical fitness components in healthy sedentary obese youth. Out of 73 participants, only 37; [14 males and 23 females; age 13.4 ± 0.9 years; body-mass-index (BMI): 31.2 ± 4.8 kg·m-2] were eligible and randomized into three groups: HIIT (n = 12): 3-4 sets×12 runs at 80–110% peak velocity, with 10-s passive recovery between bouts; RT (n = 12): 6 exercises; 3–4 sets × 10 repetition maximum (RM) and CT (n = 13): 50% serial completion of RT and HIIT. CT promoted significant greater gains compared to HIIT and RT on body composition (p < 0.01, d = large), 6-min-walking test distance (6 MWT-distance) and on 6 MWT-VO2max (p < 0.03, d = large). In addition, CT showed substantially greater improvements than HIIT in the medicine ball throw test (20.2 vs. 13.6%, p < 0.04, d = large). On the other hand, RT exhibited significantly greater gains in relative hand grip strength (p < 0.03, d = large) and CMJ (p < 0.01, d = large) than HIIT and CT. CT promoted greater benefits for fat, body mass loss and cardiorespiratory fitness than HIIT or RT modalities. This study provides important information for practitioners and therapists on the application of effective exercise regimes with obese youth to induce significant and beneficial body composition changes. The applied CT program and the respective programming parameters in terms of exercise intensity and volume can be used by practitioners as an effective exercise treatment to fight the pandemic overweight and obesity in youth.

Effects of Different Resistance Exercise Forms on Body Composition and Muscle Strength in Overweight and/or Obese Individuals: A Systematic Review and Meta-Analysis

Purpose

This study is a systematic review and meta-analysis to determine the effects of different forms of resistance training on body composition and muscle strength in overweight and/or obese people.

Method

Only randomized controlled trials (RCTs) were included by searching relevant databases such as a web of science, PubMed, and EBSCO, with search dates up to September 30, 2021. These trials performed resistance exercise training in overweight and/or obese people, and outcome indicators included evaluation of body composition and muscle strength, among other relevant indicators. The Cochrane evaluation tool was used to evaluate the methodological quality of the included literature, and statistical analysis was performed using the R analysis software.

Results

Fifteen studies, 18 trials, with a total of 669 participants meeting eligibility criteria were included in the final analysis, which included three resistance training types (own body weight, resistance bands, and free weight). The results showed that resistance bands improved body fat (BF; SMD −0.79, 95% CI −1.25 to −0.33, I2 = 0%) in overweight or obese people better than other resistance training types. Own body weight resistance training was better for increasing skeletal muscle mass in overweight or obese people (SMD 0.48, 95% CI 0.04–0.92, I2 = 0%). In addition, for muscle strength increase, although resistance exercise was shown to improve muscle strength, there was no significant difference between the three exercise forms compared.

Conclusion

Resistance bands can improve body composition by reducing BF. Resistance bands can improve body composition by reducing BF, while it is more effective in increasing muscle mass and own body weight. Therefore, for overweight and obese people, resistance bands resistance exercise can be taken for fat loss, and resistance exercise for own body weight for further muscle gain and maintenance of muscle mass, so as to achieve the purpose of improving body composition.

The impact of resistance training on strength and correlates of physical activity in youth

Resistance training (RT) may have a positive impact on specific correlates of physical activity (PA) in inactive and/or obese youth, with strength as a possible underlying mechanism. The aim of this study was to investigate this. Twelve participants (aged 8.9 ± 1.0 years) were assigned to an experimental group (EG) or control group (CG). Pre and post intervention assessments for strength, physical self-perceptions (PSPs), weight status, fundamental movement skills (FMS), and PA levels were completed. The EG participated in a twice-weekly 10-week RT programme. There were significant group x time interactions for FMS (CAMSA total P = 0.016, CAMSA skill score P = 0.036) and stretch stature (P = 0.002) (EG larges changes than the CG). Large effect sizes for the differences in change scores between the EG and CG were evident for CAMSA total score (Hedges' g = 0.830, P = 0.138), CAMSA skill score (Hedges' g = 0.895, P = 0.112) and relative strength (Hedges' g = 0.825, P = 0.140). This study demonstrated that a 10-week RT intervention has a positive effect on strength and FMS, and may also benefit weight status and PSPs. This study supports the development of RT interventions to develop these correlates, and increase PA levels.

Randomized Controlled Trial to Increase Physical Activity Among Hispanic-American Middle School Students

BACKGROUND

Moderate-to-vigorous physical activity (MVPA) declines during adolescence, particularly among girls. In this randomized control trial, we examined MVPA in a physical activity intervention compared to physical education (PE) class as usual (TAU), stratified by sex and weight classification. Standardized BMI (zBMI) overtime was also examined.

METHODS

Hispanic-American middle school students (N = 193) were recruited from a school district in Houston, Texas. Participants were randomized to either a circuit-based physical activity intervention or TAU (PE class as usual). MVPA was assessed using accelerometry at baseline and 6 months. Repeated measures ANCOVA were conducted to examine changes in MVPA, overall and stratified by sex and weight classification. This procedure was repeated for zBMI.

RESULTS

Participants were 12.10 ± 0.63 years old and 53% were girls. Overall those in intervention increased weekday MVPA more than TAU (F(1,190) = 7.03, p < .01). Intervention girls increased weekday MVPA; whereas TAU girls decreased weekday MVPA (F(1,99) = 7.36, p < .01). Among those with obesity, there was no difference in MVPA between conditions (F(1, 56) = 0.33, p = .57), but Intervention decreased zBMI significantly more than TAU (F(1, 56) = 6.16, p < .05).

CONCLUSIONS

Structured PE classes grounded in behavioral theory may be an important strategy to prevent typical decreases in MVPA during adolescence, particularly among girls and for youth with obesity.

Muscular strength across the life course: The tracking and trajectory patterns of muscular strength between childhood and mid-adulthood in an Australian cohort

OBJECTIVES

Low muscular strength is a risk factor for current and future adverse health outcomes. However, whether levels of muscular strength persist, or track, and if there are distinct muscular strength trajectories across the life course is unclear. This study aimed to explore muscular strength trajectories between childhood and mid-adulthood.

DESIGN

Prospective longitudinal study.

METHODS

Childhood Determinants of Adult Health Study participants had their muscular strength (right and left handgrip, shoulder extension and flexion, and leg strength measured by hand-held, shoulder and leg-back dynamometers, and a combined strength score) assessed in childhood, young adulthood and mid-adulthood. The tracking of muscular strength was quantified between childhood and mid-adulthood (n=385) and young- and mid-adulthood (n=822). Muscular strength trajectory patterns were identified for participants who had their muscular strength assessed at least twice across the life course (n=1280).

RESULTS

Levels of muscular strength were persistent between childhood and mid-adulthood and between young- and mid-adulthood, with the highest tracking correlations observed for the combined strength score (childhood to mid-adulthood: r=0.47, p<0.001; young- to mid-adulthood: r=0.72, p<0.001). Three trajectories of combined muscular strength were identified across the life course; participants maintained average, above average, or below average levels of combined muscular strength.

CONCLUSIONS

Weak children are likely to become weak adults in midlife unless strategies aimed at increasing muscular strength levels are introduced. Whether interventions aimed at increasing muscular strength could be implemented in childhood to help establish favourable muscular strength trajectories across the life course and in turn, better future health, warrant further attention.

Influences of exercise interventions on overweight and obesity in children and adolescents

PURPOSE

Conflicting findings of the effects of exercise on body fat, free fat mass, insulin, insulin resistance, and physical fitness for overweight and obesity in children and adolescents. The purpose of this meta-analysis was to investigate the effects of exercise interventions in children and adolescents with overweight and obesity depending on exercise type and to build effective exercise interventions to reduce risks of metabolic disorders.

METHODS

Databases were used to find eligible studies regarding the effects of exercise interventions on overweight and obesity in children and adolescents in randomized controlled trails. Effect size was calculated using the standardized mean difference statistic and heterogeneity across studies was estimated using the Q statistic.

RESULTS

A total of 27 studies met the inclusion criteria. Children and adolescents with overweight and obesity who participated in aerobic exercise had reduced body mass index, % body fat, fasting insulin, free fat mass, TNF-α, and IL-6, and increased physical fitness compared with control groups. Reduced free fat mass in resistance exercise was not found. Glucose, insulin resistance, blood pressure, C-reactive protein (CRP), and blood markers including total cholesterol (TC), triglyceride, LDL, and HDL did not have significant change. Average exercise interventions were aerobic exercise, 3 times/week, 60 min, and 36 weeks of exercise period.

CONCLUSIONS

Aerobic exercise may be beneficial to reduce body fat, fasting insulin, and inflammatory markers, and increased physical fitness for overweight and obesity in childhood and adolescence, but resistance exercise may be added, which can help avoid muscle loss in children and adolescents with overweight and obesity.

The effects of exercise on vascular markers and C-reactive protein among obese children and adolescents: An evidence-based review

Numerous studies have evaluated the effects of exercise training on obese children and adolescents. However, the impact of aerobic and/or resistance exercise alone, without any other interventions, on vascular markers and C-reactive protein (CRP) in obese children and adolescents is still not clear. We performed a literature search in Ovid Medline, PubMed, and SCOPUS databases to identify articles on the effects of exercise on vascular markers and CRP among obese children and adolescents, published between January 2009 and May 2019. Only full-text articles in English that reported on the effect of aerobic and/or resistance exercise on the vascular markers pulse wave velocity (PWV), carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), augmentation index (AIx), or CRP in obese children and adolescents (5-19 years old) were included. The literature search identified 36 relevant articles; 9 articles that fulfilled all the inclusion criteria were selected by two independent reviewers. Aerobic exercise or a combination of aerobic and resistance exercise training significantly improved CIMT and PWV in obese children and adolescents in all studies in which they were measured (2 studies for PWV and 4 studies for CIMT). However, the effects of exercise on FMD and CRP levels were inconclusive, as only half of the studies demonstrated significant improvements (1/2 studies for FMD and 4/8 studies for CRP). The results of our review support the ability of exercise to improve vascular markers such as PWV and CIMT in obese children and adolescents. This finding is important as obesity is a modifiable risk factor of cardiovascular disease (CVD), and exercise may help in reducing the future occurrence of CVD in this population.

Sequencing Effects of Object Control and Locomotor Skill During Integrated Neuromuscular Training in 6- to 7-Year-Old Children

Duncan, MJ, Hames, T, and Eyre, ELJ. Sequencing effects of object control and locomotor skill during integrated neuromuscular training in 6- to 7-year-old children. J Strength Cond Res 33(8): 2262-2274, 2019-This study examined whether scheduling of object control (e.g., throwing, catching) and locomotor skills (e.g., running, jumping), within an integrated neuromuscular training program, result in different responses in motor competence, muscular fitness, and perceived motor competence in 6- to 7-year-old children. Seventy-seven boys and 63 girls (N = 140) from 3 primary schools were randomized into 3, 10-week interventions: Loco First (n = 50) where locomotor skills were performed first followed by object control skills, Object First (n = 48) where object control skills were performed first followed by locomotor skills, and a control group (CON) (n = 42) who undertook school physical education. Results indicated greater total motor competence in Loco First and Object First vs. CON (p = 0.001) with the increases in motor competence being greater for Object First vs. Loco First (p = 0.001). Sprint speed (10 m) was lower for object first vs. CON (p = 0.024). Standing long jump distance was greater in Loco First vs. CON (p = 0.0001) and Object First (p = 0.0001). Seated medicine ball throw distance was greater for Loco First and Object First vs. CON (both p = 0.001). Perceived motor competence was also higher for Object First vs. Loco First (p = 0.005) and CON (p = 0.001). This study suggests that scheduling object control skills before locomotor skills within school-based strength and conditioning has a greater effect on motor competence, muscular fitness, and perceived motor competence in 6- to 7-year-old children.

The effects of elastic resistance band training and green coffee bean extract supplement on novel combined indices of cardiometabolic risk in obese women

The main purpose of this study was to investigate the effects of elastic resistance band training (ERBT) and green coffee bean extract (GCBE) supplement on novel cardiometabolic indices in obese women. To this end, a total number of 60 obese women aged 30-50 years with a body mass index of > 30 kg/m² were selected for inclusion in this study and then they were randomly assigned to one of the following four groups: placebo (n = 15), GCBE supplement (n = 15), GCBE supplement + ERBT (n = 15), and placebo + ERBT (n = 15). Each commercially prepared GCBE supplement capsule used in this study contained 500 mg of GCBE supplement and it was also claimed by the manufacturer to have 50% chlorogenic acid (CGA) (250 mg). The participants in the placebo + ERBT and GCBE supplement + ERBT groups attended an 8-week ERBT program, 3 sessions / week, and 60 min each session. In the GCBE supplement + ERBT group, Framingham risk score (P = 0.018), atherogenic index of plasma (P = 0.003), and metabolic syndrome severity score (P = 0.001) significantly decreased. Taken together, the results of the present study supported the importance of supplemental and resistance-type training in improving obesity and novel cardiometabolic risk scores, despite the fact that longer nutritional and exercise interventions could enhance some cardiometabolic risk scores in obese women.

Prevention and treatment of childhood and adolescent obesity: a systematic review of meta-analyses

BACKGROUND

The goal of this systematic review is to synthesize the published meta-analyses assessing the role of nutritional, behavioral and physical activity factors/interventions on the prevention or treatment of pediatric and adolescent obesity.

METHODS

An online search was conducted in PubMed (end-of-search: September 30, 2015); English-language meta-analyses pooling observational and/or interventional studies examining weight-related indices on children and adolescents were included.

RESULTS

Sixty-six meta-analyses corresponding to more than 900,000 children and adolescents were retrieved. The majority of meta-analyses included interventional studies most of which referred to mixed or combined interventions, including components such as diet, physical activity and sedentary behavior reduction. Discrepancies between meta-analyses on observational and interventional studies were noted. Combined interventions including physical activity and nutritional modifications seemed to represent the most effective means for tackling childhood obesity.

CONCLUSIONS

Synthesis of interventional or observational evidence may yield discrepant results. The combination of enhanced physical activity and improved nutrition emerged as a promising intervention in the fight against childhood/adolescent obesity. However, further research is needed about the most effective multidimensional prevention strategy.

The Effect of Resistance Training Interventions on 'The Self' in Youth: a Systematic Review and Meta-analysis

Background

There is growing evidence that physical activity (PA) is beneficial for the mental health of young people. One area that has been widely examined is the impact of PA on ‘the self’, which is a term that encompasses a range of specific and related terms (e.g. self-esteem, self-efficacy, self-perceptions). There is evidence that PA is strongly associated with ‘the self’ in childhood and beyond. However, the impact of the specific PA of resistance training (RT) is not yet clear. The purpose of this review was to advance knowledge on the potential of RT for enhancing mental health by examining the effect of RT interventions on ‘the self’ in youth.

Methods

This systematic review followed the PRISMA guidelines (PROSPERO registration number CRD42016038365). Electronic literature databases were searched from the year of their inception to October 2018. The search included English language articles that examined the effect of isolated RT on the broad term of ‘the self’ in youth, with participants of school age (5–18 years). Data were extracted using an electronic form by one reviewer with 10% conducted by a second reviewer. The ‘Quality Assessment Tool for Quantitative Studies’ was used to assess the quality and risk of bias and was conducted by two reviewers.

Results

From seven peer-reviewed studies, ten data sets were included exploring seven outcomes related to ‘the self’ in participants aged between 10 and 16 years. Four of these studies (including seven data sets) were combined in a meta-analysis, with results from the remaining three studies reported separately. Significant intervention effects were identified for resistance training self-efficacy (Hedges’ g = 0.538, 95% CI 0.254 to 0.822, P < 0.001), physical strength (Hedges’ g = 0.289, 95% CI 0.067 to 0.511, P = 0.011), physical self-worth (Hedges’ g = 0.319, 95% CI 0.114 to 0.523, P = 0.002) and global self-worth (Hedges’ g = 0.409, 95% 0.149 to 0.669, P = 0.002). Although not statistically significant, the effect sizes for the remaining three outcomes were body attractiveness (Hedges’ g = 0.211, 95% CI − 0.031 to 0.454, P = 0.087), physical condition (Hedges’ g = 0.089, 95% CI − 0.238 to 0.417, P = 0.593) and sport competence (Hedges’ g = 0.004, 95% CI − 0.218 to 0.225, P = 0.974). There was variable quality of studies, with just two studies being classified as ‘strong’.

Conclusion

This is the first review to synthesise research on the effects of isolated RT interventions on ‘the self’. The findings indicate that RT has a positive impact on some aspects of ‘the self’ in youth. More high-quality studies should be conducted to further investigate this topic. If validated, this type of intervention could have a positive impact on ‘the self’ and ultimately improve the health of individuals not only during childhood but as they progress through life.

The Effects of 10-week Integrated Neuromuscular Training on Fundamental Movement Skills and Physical Self-efficacy in 6-7-Year-Old Children

Duncan, MJ, Eyre, ELJ, and Oxford, SW. The effects of 10-week integrated neuromuscular training on fundamental movement skills and physical self-efficacy in 6-7-year-old children. J Strength Cond Res 32(12): 3348-3356, 2018-Integrated neuromuscular training (INT) has been suggested as an effective means to enhance athletic potential in children. However, few studies have reported the effects of school-based INT programs. This study examined the effect of INT on process and product fundamental movement skill measures and physical self-efficacy in 6-7-year-old children. Ninety-four children from 2 primary schools were randomized into either a 10-week INT program or a control group (CON) (n = 41). Results indicated significantly greater increases in process fundamental movement skill (FMS) scores in INT vs. CON (p = 0.001). For product measures of FMS, 10-m sprint time, counter movement jump, seated medicine ball throw and standing long jump (all p = 0.001), all significantly increased to a greater extent in the INT group vs. CON. A significant group (INT vs. CON) × time (pre vs. post) × gender interaction for physical self-efficacy revealed increased physical self-efficacy pre to post INT, compared with CON but only for boys (p = 0.001). For girls, physical self-efficacy was not significantly different before to after the 10-week period for INT and CON groups. The results of this study suggest that replacing 1 of the 2 weekly statutory physical education (PE) lessons with an INT program over a 10-week period results in positive improvements in fundamental movement skill quality and outcomes in 6-7-year-old children. Integrated neuromuscular training also appears to increase physical self-esteem to a greater extent than statutory PE but only in boys.

Physical activity for children with chronic disease; a narrative review and practical applications

BACKGROUND

Physical activity (PA) is associated with a diverse range of health benefits. International guidelines suggest that children should be participating in a minimum of 60 min of moderate to vigorous intensity PA per day to achieve these benefits. However, current guidelines are intended for healthy children, and thus may not be applicable to children with a chronic disease. Specifically, the dose of PA and disease specific exercise considerations are not included in these guidelines, leaving such children with few, if any, evidence-based informed suggestions pertaining to PA. Thus, the purpose of this narrative review was to consider current literature in the area of exercise as medicine and provide practical applications for exercise in five prevalent pediatric chronic diseases: respiratory, congenital heart, metabolic, systemic inflammatory/autoimmune, and cancer.

METHODS

For each disease, we present the pathophysiology of exercise intolerance, summarize the pediatric exercise intervention research, and provide PA suggestions.

RESULTS

Overall, exercise intolerance is prevalent in pediatric chronic disease. PA is important and safe for most children with a chronic disease, however exercise prescription should involve the entire health care team to create an individualized program.

CONCLUSIONS

Future research, including a systematic review to create evidence-based guidelines, is needed to better understand the safety and efficacy of exercise among children with chronic disease.

The Psychological Effects of Strength Exercises in People who are Overweight or Obese: A Systematic Review

BACKGROUND

Overweightness and obesity represent a high burden on well-being and society. Strength training has positive effects on body composition and metabolic health for people who are overweight or obese. The evidence for psychological effects of strength exercises is unclear.

OBJECTIVE

The aim of this study was to assess the psychological effects of strength exercises for people who are overweight or obese.

METHODS

Relevant literature was identified by use of the PubMed and PsycINFO databases. For each study, effect sizes and corresponding variance estimates were extracted or calculated for the main effects of strength exercises on psychological outcomes.

RESULTS

Seventeen studies were included. There was almost no overlap among the various measures of psychological constructs. The constructs were ordered into eight broad categories. Meta-analytical techniques revealed substantial heterogeneity in effect sizes, and combined with the low number of effect size estimates for each outcome measure, this precluded meta-analysis. Organization of the data showed that the evidence base so far does not show convincing effects of strength training on psychological outcome measures. Some weak effects emerged on self-efficacy, self-esteem, inhibition, and psychological disorders (e.g., anxiety and depression). No additional or comparable effects to other interventions were found for mood, outcome expectations, quality of life, and stress.

DISCUSSION

The main finding of this review is that despite a strong theoretical basis for expecting positive effects of strength training on psychological outcomes, the literature shows a large gap in this area. The existing research does not show a clear picture: some positive results might exist, but there is a strong need to accumulate more evidence before drawing conclusions.

The great leap backward: changes in the jumping performance of Australian children aged 11-12-years between 1985 and 2015

Previous data have indicated relative stability over time of paediatric jumping performance, but few data exist since the early 2000s. This study quantified the 30-year secular changes in jumping performance of Australian children aged 11-12-years using data from the Australian Schools Health and Fitness Survey (1985, n = 1967) and Growing Up in Australia's Child Health CheckPoint (2015, n = 1765). Both cohorts measured jumping performance (standing long jump distance), anthropometric and demographic data. Secular changes in jumping performance means and quantiles were examined using multivariable linear and quantile regression. Between 1985 and 2015, jumping performance declined by 16.4 cm or by 11.2% (standardised change 0.66 SD, 95%CI 0.60 to 0.73). Adjustment for body mass reduced the effect by 32%, although the decline remained (absolute change - 11.1 cm, 95%CI -12.5 to -9.7; percent change 7.7%, 95%CI 6.7 to 8.6; standardised change 0.51 SD, 95%CI 0.44 to 0.57). This decline was evident across all quantiles. The jumping performance of Australian children aged 11-12-years has declined between 1985 and 2015, with body mass changes accounting for only part of the decline. Efforts should continue to promote paediatric muscular fitness, reduce adiposity, and aim to reverse this decline in jumping performance.

A systematic review on the effects of resistance and plyometric training on physical fitness in youth- What do comparative studies tell us?

INTRODUCTION

To date, several meta-analyses clearly demonstrated that resistance and plyometric training are effective to improve physical fitness in children and adolescents. However, a methodological limitation of meta-analyses is that they synthesize results from different studies and hence ignore important differences across studies (i.e., mixing apples and oranges). Therefore, we aimed at examining comparative intervention studies that assessed the effects of age, sex, maturation, and resistance or plyometric training descriptors (e.g., training intensity, volume etc.) on measures of physical fitness while holding other variables constant.

METHODS

To identify relevant studies, we systematically searched multiple electronic databases (e.g., PubMed) from inception to March 2018. We included resistance and plyometric training studies in healthy young athletes and non-athletes aged 6 to 18 years that investigated the effects of moderator variables (e.g., age, maturity, sex, etc.) on components of physical fitness (i.e., muscle strength and power).

RESULTS

Our systematic literature search revealed a total of 75 eligible resistance and plyometric training studies, including 5,138 participants. Mean duration of resistance and plyometric training programs amounted to 8.9 ± 3.6 weeks and 7.1±1.4 weeks, respectively. Our findings showed that maturation affects plyometric and resistance training outcomes differently, with the former eliciting greater adaptations pre-peak height velocity (PHV) and the latter around- and post-PHV. Sex has no major impact on resistance training related outcomes (e.g., maximal strength, 10 repetition maximum). In terms of plyometric training, around-PHV boys appear to respond with larger performance improvements (e.g., jump height, jump distance) compared with girls. Different types of resistance training (e.g., body weight, free weights) are effective in improving measures of muscle strength (e.g., maximum voluntary contraction) in untrained children and adolescents. Effects of plyometric training in untrained youth primarily follow the principle of training specificity. Despite the fact that only 6 out of 75 comparative studies investigated resistance or plyometric training in trained individuals, positive effects were reported in all 6 studies (e.g., maximum strength and vertical jump height, respectively).

CONCLUSIONS

The present review article identified research gaps (e.g., training descriptors, modern alternative training modalities) that should be addressed in future comparative studies.

The effect of resistance training interventions on weight status in youth: a meta-analysis

BACKGROUND

There has been a rise in research into obesity prevention and treatment programmes in youth, including the effectiveness of resistance-based exercise. The purpose of this meta-analysis was to examine the effect of resistance training interventions on weight status in youth.

METHODS

Meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered on PROSPERO (registration number CRD42016038365). Eligible studies were from English language peer-reviewed published articles. Searches were conducted in seven databases between May 2016 and June 2017. Studies were included that examined the effect of resistance training on weight status in youth, with participants of school age (5-18 years).

RESULTS

There were 24 complete sets of data from 18 controlled trials (CTs) which explored 8 outcomes related to weight status. Significant, small effect sizes were identified for body fat% (Hedges' g = 0.215, 95% CI 0.059 to 0.371, P = 0.007) and skinfolds (Hedges' g = 0.274, 95% CI 0.066 to 0.483, P = 0.01). Effect sizes were not significant for: body mass (Hedges' g = 0.043, 95% CI - 0.103 to 0.189, P = 0.564), body mass index (Hedges' g = 0.024, 95% CI - 0.205 to 0.253, P = 0.838), fat-free mass (Hedges' g = 0.073, 95% CI - 0.169 to 0.316, P = 0.554), fat mass (Hedges' g = 0.180, 95% CI - 0.090 to 0.451, P = 0.192), lean mass (Hedges' g = 0.089, 95% CI - 0.122 to 0.301, P = 0.408) or waist circumference (Hedges' g = 0.209, 95% CI - 0.075 to 0.494, P = 0.149).

CONCLUSIONS

The results of this meta-analysis suggest that an isolated resistance training intervention may have an effect on weight status in youth. Overall, more quality research should be undertaken to investigate the impact of resistance training in youth as it could have a role to play in the treatment and prevention of obesity.

Health outcomes associated with reallocations of time between sleep, sedentary behaviour, and physical activity: a systematic scoping review of isotemporal substitution studies

Background

During a 24-h day, each given period is spent in either sedentary behaviour, sleeping, light physical activity (LPA), or moderate-to-vigorous physical activity (MVPA). In epidemiological research most studies have traditionally analysed the associations of these behaviours in isolation from each other; that is, without taking into account the displacement of time spent in the remaining behaviours. In recent years, there has been a growing interest in exploring how all the behaviours across the energy expenditure spectrum influence health outcomes. A statistical model used to investigate these associations is termed an isotemporal substitution model (ISM). Considering the increasing number of ISM-based studies conducted in all age groups, the present paper aimed to: (i) review and summarise findings from studies that employed ISM in sleep, sedentary behaviour, and physical activity research; (ii) appraise the methodological quality of the studies; and (iii) suggest future research directions in this area.

Methods

A systematic search of ten databases was performed. The Newcastle–Ottawa scale was used to assess the methodological quality of the included studies.

Results

Fifty-six studies met the inclusion criteria, all being of moderate or high methodological quality. Associations were reported for exchanged time varying from one minute to 120 min/day across the studies, with 30 min/day being the most common amount of time reallocated. In total, three different ISM methodologies were used. The most commonly studied health outcomes in relation to isotemporal substitutions were mortality, general health, mental health, adiposity, fitness, and cardiometabolic biomarkers. It seems that reallocations of sedentary time to LPA or MVPA are associated with significant reduction in mortality risk. Current evidence appears to consistently suggest that reductions in mortality risk are greater when time spent sedentary is replaced with higher intensities of physical activity. For adiposity, it seems that reallocating sedentary time to physical activity may be associated with reduced body mass index, body fat percentage, and waist circumference in all age groups, with the magnitude of associations being greater for higher intensities of physical activity. While there is a relatively large body of evidence reporting beneficial associations between the reallocation of time from sedentary behaviour to LPA or MVPA and cardiometabolic biomarkers among adults, there is a lack of studies among children, adolescents, and older adults. Although some studies investigated general health, mental health, and fitness outcomes, further investigation of these topics is warranted. In general, it seems that the strongest association with health outcomes is observed when time is reallocated from sedentary behaviour to MVPA. Most studies did not account for sleep time, which is a major limitation of the current evidence.

Conclusions

The current evidence indicates that time reallocation between sleep, sedentary behaviour, LPA, and MVPA may be associated with a number of health outcomes. Future studies should employ longitudinal designs, take into account all movement behaviours, and examine a wider range of health, psychological, social, economic, and environmental outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0691-3) contains supplementary material, which is available to authorized users.

The Effects of Resistance Training on Health of Children and Adolescents With Disabilities

Many parents still hesitate to encourage their children to participate in resistance training programs. This is unfortunate since recent research shows that resistance training can positively affect children's health. This narrative review aims to present an overview of the health-associated effects resistance training can provide particularly in children and adolescents with disabilities by describing its effects on muscle strength, physical function, mental health, self-concept, obesity, and injury prevention. To illustrate the variety of possible fields of application, the effects of resistance training in children and adolescents suffering from Charcot-Marie-Tooth disease, cerebral palsy, Down syndrome, Ehlers-Danlos syndrome, joint hypermobility, juvenile idiopathic arthritis, obesity, and spina bifida are discussed. Although randomized controlled trials with a sufficiently large sample size are rare, the research presented in this review indicates that this mode of training might be a potent tool to improve mental and physical health by improving muscle strength, body composition, self-concept or functionality, reducing pain or injury risk, and strengthening bone or tendons even in the most vulnerable groups of children with physical or mental disability. Furthermore, it has to be emphasized that compared with other types of treatment resistance training is considered to be without adverse effects.

Exercise and adiposity in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

Overweight and obesity is a worldwide public health problem among children and adolescents. However, the magnitude of effect, as well as hierarchy of exercise interventions (aerobic, strength training or both), on selected measures of adiposity is not well established despite numerous trials on this issue. The primary purposes of this study are to use the network meta-analytical approach to determine the effects and hierarchy of exercise interventions on selected measures of adiposity in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, available in any language up to 31 August 2017 and which include direct and/or indirect evidence, will be included. Studies will be located by searching seven electronic databases, cross-referencing and expert review. Dual selection and abstraction of data will occur. The primary outcomes will be changes in body mass index (in kg/m²), fat mass and percent body fat. Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength or both).

ETHICS AND DISSEMINATION

This study does not require ethics approval. Findings will be presented at a professional conference and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD 42017073103 .

Childhood Muscular Fitness Phenotypes and Adult Metabolic Syndrome

PURPOSE

The objective of this study is to determine whether childhood muscular fitness phenotypes (strength, endurance, and power) are independently associated with adult metabolic syndrome (MetS).

METHODS

We conducted a longitudinal study including 737 participants who had muscular fitness measures in 1985 when age 9, 12, or 15 yr and attended follow-up in young adulthood 20 yr later when measures of MetS were collected. Childhood measures of muscular fitness included strength (right and left grip, leg, and shoulder extension and flexion), endurance (number of push-ups in 30 s), and power (distance of a standing long jump). A muscular fitness score was created using all individual muscular fitness phenotypes. In adulthood, waist circumference, blood pressure, HDL cholesterol, triglycerides, and glucose were measured. Adult outcomes were MetS defined using the harmonized definition and a continuous MetS risk score.

RESULTS

Participants with childhood muscular strength, muscular power, and combined muscular fitness score in the highest third had significantly lower relative risk (RR) for MetS and a lower continuous MetS score in adulthood independent of cardiorespiratory fitness than those in the lowest third (strength: RR = 0.21 (0.09, 0.49) β = -0.46 (-0.59, -0.34) power: RR = 0.26 (0.12, 0.60), β = -0.36 (-0.49, -0.23) fitness score: RR = 0.20 (0.09, 0.47), β = -0.45 (-0.58, -0.33)). However, adjustment for childhood waist circumference reduced the effect sizes for both adult outcomes by 17%-60%.

CONCLUSION

Phenotypes of childhood muscular fitness can be used to predict adult MetS independent of cardiorespiratory fitness. Although a large proportion of the effect of childhood muscular fitness on adult MetS is potentially being mediated by child waist circumference, these data suggest that promotion of muscular fitness among children might provide additional protection against developing adult MetS.

Resistance Training Effects on Metabolic Function Among Youth: A Systematic Review

PURPOSE

This systematic review evaluates the relationship between resistance training and metabolic function in youth.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, CINAHL, and ClinicalTrials. gov were searched for articles that (1): studied children (2); included resistance training (3); were randomized interventions; and (4) reported markers of metabolic function. The selected studies were analyzed using the Cochrane Risk-of-Bias Tool.

RESULTS

Thirteen articles met inclusion criteria. Mean age ranged from 12.2 to 16.9 years, but most were limited to high school (n = 11) and overweight/obese (n = 12). Sample sizes (n = 22-304), session duration (40-60min), and intervention length (8-52 wks) varied. Exercise frequency was typically 2-3 d/wk. Resistance training was metabolically beneficial compared with control or resistance plus aerobic training in 5 studies overall and 3 out of the 4 studies with the fewest threats to bias (p ≤ .05); each was accompanied by beneficial changes in body composition, but only one study adjusted for change in body composition.

CONCLUSIONS

Limited evidence suggests that resistance training may positively affect metabolic parameters in youth. Well-controlled resistance training interventions of varying doses are needed to definitively determine whether resistance training can mitigate metabolic dysfunction in youth and whether training benefits on metabolic parameters are independent of body composition changes.

Metabolic effects of resistance or high-intensity interval training among glycemic control-nonresponsive children with insulin resistance

BACKGROUND

Little evidence exists on which variables of body composition or muscular strength mediates more glucose control improvements taking into account inter-individual metabolic variability to different modes of exercise training.

OBJECTIVE

We examined 'mediators' to the effects of 6-weeks of resistance training (RT) or high-intensity interval training (HIT) on glucose control parameters in physically inactive schoolchildren with insulin resistance (IR). Second, we also determined both training-induce changes and the prevalence of responders (R) and non-responders (NR) to decrease the IR level.

METHODS

Fifty-six physically inactive children diagnosed with IR followed a RT or supervised HIT program for 6 weeks. Participants were classified based on ΔHOMA-IR into glycemic control R (decrease in homeostasis model assessment-IR (HOMA-IR) <3.0 after intervention) and NRs (no changes or values HOMA-IR⩾3.0 after intervention). The primary outcome was HOMA-IR associated with their mediators; second, the training-induced changes to glucose control parameters; and third the report of R and NR to improve body composition, cardiovascular, metabolic and performance variables.

RESULTS

Mediation analysis revealed that improvements (decreases) in abdominal fat by the waist circumference can explain more the effects (decreases) of HOMA-IR in physically inactive schoolchildren under RT or HIT regimes. The same analysis showed that increased one-maximum repetition leg-extension was correlated with the change in HOMA-IR (β=-0.058; P=0.049). Furthermore, a change in the waist circumference fully mediated the dose-response relationship between changes in the leg-extension strength and HOMA-IR (β'=-0.004; P=0.178). RT or HIT were associated with significant improvements in body composition, muscular strength, blood pressure and cardiometabolic parameters irrespective of improvement in glycemic control response. Both glucose control RT-R and HIT-R (respectively), had significant improvements in mean HOMA-IR, mean muscular strength leg-extension and mean measures of adiposity.

CONCLUSIONS

The improvements in the lower body strength and the decreases in waist circumference can explain more the effects of the improvements in glucose control of IR schoolchildren in R group after 6 weeks of RT or HIT, showing both regimes similar effects on body composition or muscular strength independent of interindividual metabolic response variability.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

AIM

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents.

METHODS

Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U₃ ) were also calculated.

RESULTS

Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training.

CONCLUSIONS

Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score.

Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline

COSPONSORING ASSOCIATIONS

The European Society of Endocrinology and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society.

OBJECTIVE

To formulate clinical practice guidelines for the assessment, treatment, and prevention of pediatric obesity.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of 6 experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The Task Force commissioned 2 systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and co-sponsoring organizations reviewed and commented on preliminary drafts of this guideline.

CONCLUSION

Pediatric obesity remains an ongoing serious international health concern affecting ∼17% of US children and adolescents, threatening their adult health and longevity. Pediatric obesity has its basis in genetic susceptibilities influenced by a permissive environment starting in utero and extending through childhood and adolescence. Endocrine etiologies for obesity are rare and usually are accompanied by attenuated growth patterns. Pediatric comorbidities are common and long-term health complications often result; screening for comorbidities of obesity should be applied in a hierarchal, logical manner for early identification before more serious complications result. Genetic screening for rare syndromes is indicated only in the presence of specific historical or physical features. The psychological toll of pediatric obesity on the individual and family necessitates screening for mental health issues and counseling as indicated. The prevention of pediatric obesity by promoting healthful diet, activity, and environment should be a primary goal, as achieving effective, long-lasting results with lifestyle modification once obesity occurs is difficult. Although some behavioral and pharmacotherapy studies report modest success, additional research into accessible and effective methods for preventing and treating pediatric obesity is needed. The use of weight loss medications during childhood and adolescence should be restricted to clinical trials. Increasing evidence demonstrates the effectiveness of bariatric surgery in the most seriously affected mature teenagers who have failed lifestyle modification, but the use of surgery requires experienced teams with resources for long-term follow-up. Adolescents undergoing lifestyle therapy, medication regimens, or bariatric surgery for obesity will need cohesive planning to help them effectively transition to adult care, with continued necessary monitoring, support, and intervention. Transition programs for obesity are an uncharted area requiring further research for efficacy. Despite a significant increase in research on pediatric obesity since the initial publication of these guidelines 8 years ago, further study is needed of the genetic and biological factors that increase the risk of weight gain and influence the response to therapeutic interventions. Also needed are more studies to better understand the genetic and biological factors that cause an obese individual to manifest one comorbidity vs another or to be free of comorbidities. Furthermore, continued investigation into the most effective methods of preventing and treating obesity and into methods for changing environmental and economic factors that will lead to worldwide cultural changes in diet and activity should be priorities. Particular attention to determining ways to effect systemic changes in food environments and total daily mobility, as well as methods for sustaining healthy body mass index changes, is of importance.

Different consecutive training protocols to design an intervention program for overweight youth: a controlled study

OBJECTIVE

To find the optimal exercise program to be recommended in reducing adiposity and promoting long-term physical activity adherence in a sample of overweight adolescents.

METHODS

Forty-five overweight adolescents were randomly divided into three exercise groups, to perform two phases of physical activity as follows: in the first phase, the first group performed a 16-week moderate-intensity resistance training (RT), the second group performed a 16-week high-intensity RT, and the third group performed a 16-week aerobic training (AT); in the second phase, all groups performed a 6-week AT. Anthropometric body composition and fitness measures were considered as outcome measures.

RESULTS

After the second protocol, both RT groups showed a significant improvement in percentage of fat mass (F_2,76 = 5.843; p = 0.004; h² = 0.133) and free fat mass (F_2,76 = 6.254; p = 0.003; h² = 0.141), and in fitness tests (p < 0.01). The VO₂max values of the RT groups were significantly higher than those of the AT group (F_2,38 = 4.264; p = 0.021; h² = 0.183). The rate of adherence to exercise was an average of 94% in both RT groups, whereas in the AT group, it was 83%. During the 12-week post-intervention follow-up, the number of participants who continued to perform physical activities was significantly higher in both the RT groups than in the AT group (p < 0.05).

CONCLUSION

The present study provides preliminary evidence that moderate-to-intense RT, followed by AT, can be an effective treatment for overweight adolescents, and the positive effects are maintained even after 12 weeks of follow-up.

National Strength and Conditioning Association Position Statement on Long-Term Athletic Development

There has recently been a growing interest in long-term athletic development for youth. Because of their unique physical, psychological, and social differences, children and adolescents should engage in appropriately prescribed exercise programs that promote physical development to prevent injury and enhance fitness behaviors that can be retained later in life. Irrespective of whether a child is involved in organized sport or engages in recreational physical activity, there remains a need to adopt a structured, logical, and evidence-based approach to the long-term development of athleticism. This is of particular importance considering the alarmingly high number of youth who fail to meet global physical activity recommendations and consequently present with negative health profiles. However, appropriate exercise prescription is also crucial for those young athletes who are physically underprepared and at risk of overuse injury because of high volumes of competition and an absence of preparatory conditioning. Whether the child accumulates insufficient or excessive amounts of exercise, or falls somewhere between these opposing ends of the spectrum, it is generally accepted that the young bodies of modern day youth are often ill-prepared to tolerate the rigors of sports or physical activity. All youth should engage in regular physical activity and thus should be viewed as "athletes" and afforded the opportunity to enhance athleticism in an individualized, holistic, and child-centered manner. Because of emerging interest in long-term athletic development, an authorship team was tasked on behalf of the National Strength and Conditioning Association (NSCA) to critically synthesize existing literature and current practices within the field and to compose a relevant position statement. This document was subsequently reviewed and formally ratified by the NSCA Board of Directors. A list of 10 pillars of successful long-term athletic development are presented, which summarize the key recommendations detailed within the position statement. With these pillars in place, it is believed that the NSCA can (a) help foster a more unified and holistic approach to long-term athletic development, (b) promote the benefits of a lifetime of healthy physical activity, and

Concurrent aerobic plus resistance exercise versus aerobic exercise alone to improve health outcomes in paediatric obesity: a systematic review and meta-analysis

OBJECTIVE

To determine if the combination of aerobic and resistance exercise is superior to aerobic exercise alone for the health of obese children and adolescents.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Computerised search of 3 databases (MEDLINE, EMBASE, and Cochrane Controlled Trials Registry).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that compared the effect of supervised concurrent exercise versus aerobic exercise interventions, with anthropometric and metabolic outcomes in paediatric obesity (6-18 years old). The mean differences (MD) of the parameters from preintervention to postintervention between groups were pooled using a random-effects model.

RESULTS

12 trials with 555 youths were included in the meta-analysis. Compared with aerobic exercise alone, concurrent exercise resulted in greater reductions in body mass (MD=-2.28 kg), fat mass (MD=-3.49%; and MD=-4.34 kg) and low-density lipoprotein cholesterol (MD=-10.20 mg/dL); as well as greater increases in lean body mass (MD=2.20 kg) and adiponectin level (MD=2.59 μg/mL). Differences were larger for longer term programmes (>24 weeks).

SUMMARY

Concurrent aerobic plus resistance exercise improves body composition, metabolic profiles, and inflammatory state in the obese paediatric population.

TRIAL REGISTRATION NUMBER

CRD42016039807.

Physical Activity for Cognitive and Mental Health in Youth: A Systematic Review of Mechanisms

CONTEXT

Physical activity can improve cognitive and mental health, but the underlying mechanisms have not been established.

OBJECTIVE

To present a conceptual model explaining the mechanisms for the effect of physical activity on cognitive and mental health in young people and to conduct a systematic review of the evidence.

DATA SOURCES

Six electronic databases (PubMed, PsycINFO, SCOPUS, Ovid Medline, SportDiscus, and Embase) were used.

STUDY SELECTION

School-, home-, or community-based physical activity intervention or laboratory-based exercise interventions were assessed. Studies were eligible if they reported statistical analyses of changes in the following: (1) cognition or mental health; and (2) neurobiological, psychosocial, and behavioral mechanisms.

DATA EXTRACTION

Data relating to methods, assessment period, participant characteristics, intervention type, setting, and facilitator/delivery were extracted.

RESULTS

Twenty-five articles reporting results from 22 studies were included. Mechanisms studied were neurobiological (6 studies), psychosocial (18 studies), and behavioral (2 studies). Significant changes in at least 1 potential neurobiological mechanism were reported in 5 studies, and significant effects for at least 1 cognitive outcome were also found in 5 studies. One of 2 studies reported a significant effect for self-regulation, but neither study reported a significant impact on mental health.

LIMITATIONS

Small number of studies and high levels of study heterogeneity.

CONCLUSIONS

The strongest evidence was found for improvements in physical self-perceptions, which accompanied enhanced self-esteem in the majority of studies measuring these outcomes. Few studies examined neurobiological and behavioral mechanisms, and we were unable to draw conclusions regarding their role in enhancing cognitive and mental health.

Assessing the sustained impact of a school-based obesity prevention program for adolescent boys: the ATLAS cluster randomized controlled trial

BACKGROUND

Obesity prevention interventions targeting 'at-risk' adolescents are urgently needed. The aim of this study is to evaluate the sustained impact of the 'Active Teen Leaders Avoiding Screen-time' (ATLAS) obesity prevention program.

METHODS

Cluster RCT in 14 secondary schools in low-income communities of New South Wales, Australia. Participants were 361 adolescent boys (aged 12-14 years) 'at risk' of obesity. The intervention was based on Self-Determination Theory and Social Cognitive Theory and involved: professional development, fitness equipment for schools, teacher-delivered physical activity sessions, lunch-time activity sessions, researcher-led seminars, a smartphone application, and parental strategies. Assessments for the primary (body mass index [BMI], waist circumference) and secondary outcomes were conducted at baseline, 8- (post-intervention) and 18-months (follow-up). Analyses followed the intention-to-treat principle using linear mixed models.

RESULTS

After 18-months, there were no intervention effects for BMI or waist circumference. Sustained effects were found for screen-time, resistance training skill competency, and motivational regulations for school sport.

CONCLUSIONS

There were no clinically meaningful intervention effects for the adiposity outcomes. However, the intervention resulted in sustained effects for secondary outcomes. Interventions that more intensively target the home environment, as well as other socio-ecological determinants of obesity may be needed to prevent unhealthy weight gain in adolescents from low-income communities.

TRIAL REGISTRATION

Australian Clinical Trial Registry ACTRN12612000978864.

Effectiveness of resistance strength training in children and adolescents with ≥30% total body surface area: A systematic review

Purpose

Children and adolescents with burn injuries are at risk of living with social, educational, physical and psychological impairments. The systematic review aimed to ascertain the effectiveness of resistance strength training on muscle strength and lean body mass (LBM) in children and adolescents with burn injuries.

Method

Five databases were searched. Randomised controlled trials with an intervention defined as a supervised, individualised resistance exercise programme were sought. The outcomes included muscle strength and/or LBM. The PEDro scale was used to describe the methodological quality. Comparable data were combined using RevMan^©.

Results

Seven papers were included in the review with an average methodological appraisal score of 5.7/11. Comparable data were combined for muscle strength and LBM. The meta-analysis revealed no significant clinical difference between the exercise and standard care groups after 3 months of strength training for both muscle strength (p = 0.43) and LBM (p = 0.60).

Conclusions

There is no conclusive evidence to support the benefit of strength training for children and adolescents with burns injuries in terms of muscle strength and LBM. However, it appears that isokinetic training might benefit children and adolescents with burns, but more studies investigating the effect of isokinetic training are required.

The Dutch 'Focus on Strength' intervention study protocol: programme design and production, implementation and evaluation plan

BACKGROUND

Overweight youngsters are better in absolute strength exercises than their normal-weight counterparts; a physiological phenomenon with promising psychological impact. In this paper we describe the study protocol of the Dutch, school-based program 'Focus on Strength' that aims to improve body composition of 11-13 year old students, and with that to ultimately improve their quality of life.

METHODS

The development of this intervention is based on the Intervention Mapping (IM) protocol, which starts from a needs assessment, uses theory and empirical research to develop a detailed intervention plan, and anticipates program implementation and evaluation. This novel intervention targets first year students in preparatory secondary vocational education (11-13 years of age). Teachers are the program implementers. One part of the intervention involves a 30 % increase of strength exercises in the physical education lessons. The other part is based on Motivational Interviewing, promoting autonomous motivation of students to become more physically active outside school. Performance and change objectives are described for both teachers and students. The effectiveness of the intervention will be tested in a Randomized Controlled Trial in 9 Dutch high schools.

DISCUSSION

Intervention Mapping is a useful framework for program planning a school-based program to improve body composition and motivation to exercise in 11-13 year old adolescents by a "Focus on Strength".

TRIAL REGISTRATION

NTR5676 , registered 8 February 2016 (retrospectively registered).

Exercise and BMI z-score in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

While overweight and obesity in children and adolescents is a major global health problem, the effects of exercise on overweight and obesity in children and adolescents are not well established despite numerous studies on this topic. The purpose of this study is to use the network meta-analytic approach to determine the effects of exercise (aerobic, strength training or both) on body mass index (BMI) z-score in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, published in any language between 1 January 1990 and 31 September 2015, and which include direct and/or indirect evidence, will be included. Studies will be retrieved by searching 6 electronic databases, cross-referencing and expert review. Dual abstraction of data will occur. The primary outcome will be changes in BMI z-score while the secondary outcome will be changes in body weight in kilograms (kg). Risk of bias will be assessed using the Cochrane risk of bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength training or both).

DISSEMINATION

The results of this study will be presented at a professional conference and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

CRD42015026377.

Concurrent and aerobic exercise training promote similar benefits in body composition and metabolic profiles in obese adolescents

BACKGROUND

The prevalence of obesity in pediatric population is increasing at an accelerated rate in many countries, and has become a major public health concern. Physical activity, particularly exercise training, remains to be a cornerstone of pediatric obesity interventions. The purpose of our current randomized intervention trial was to compare the effects of two types of training matched for training volume, aerobic and concurrent, on body composition and metabolic profile in obese adolescents. Thus the aim of the study was compare the effects of two types of training matched for training volume, aerobic and concurrent, on body composition and metabolic profile in obese adolescents.

METHODS

32 obese adolescents participated in two randomized training groups, concurrent or aerobic, for 20 weeks (50 mins x 3 per week, supervised), and were compared to a 16-subject control group. We measured the percentage body fat (%BF, primary outcome), fat-free mass, percentage of android fat by dual energy x-ray absorptiometry, and others metabolic profiles at baseline and after interventions, and compared them between groups using the Intent-to-treat design.

RESULTS

In 20 weeks, both exercise training groups significantly reduced %BF by 2.9-3.6% as compare to no change in the control group (p = 0.042). There were also positive changes in lipid levels in exercise groups. No noticeable changes were found between aerobic and concurrent training groups.

CONCLUSIONS

The benefits of exercise in reducing body fat and metabolic risk profiles can be achieved by performing either type of training in obese adolescents.

TRIAL REGISTRATION

REGISTRATION NUMBER

RBR-4HN597.