A review of resistance exercise training in obese adolescents

The Benefits of Resistance Training in Obese Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Physical activity is essential in acquiring healthy lifestyle behaviors in the early years of maturational development and preventing various diseases. Resistance training (RT) is fundamental for improving body composition and is increasingly recommended for obese adolescents. A systematic review and meta-analysis were performed to synthesize and analyze data on the effects of RT programs in this population, seeking to develop useful recommendations for health and sports professionals.

METHODS

A search was performed using four databases (Web of Science, Scopus, PubMed, and ScienceDirect). According to specific inclusion criteria, twenty-one studies were selected to evaluate the impact of RT on body mass index (BMI), body fat, waist circumference, muscle strength, insulin sensitivity, lean mass and cardiorespiratory fitness.

RESULTS

After the RT programs, the adolescents improved their muscle strength (SMD, 1.44; 95% CI: 0.76-2.12), cardiorespiratory fitness (SMD, 1.09; 95% CI: 0.15-2.04), BMI (SMD, 0.21; 95% CI: 0.07-0.35), waist circumference (SMD, 0.27; 95% CI: 0.06-0.47) and body fat (SMD, 0.20; 95% CI: 0.05-0.34). However, insulin sensitivity (SMD, 0.32; 95% CI: - 0.47 to 1.10) and lean mass (SMD, 0.12; 95% CI: - 0.06 to 0.31) did not reveal any changes. Different RT programs were used but it seems that 2-3 times/week ∼60 min/session of RT for 12 weeks should be recommended for positive changes.

CONCLUSIONS

RT seems to be effective when the objective is to improve muscle strength, cardiorespiratory fitness and can be an efficient strategy to reduce obesity in adolescents by reducing body fat, waist circumference and body mass index. PROSPERO Registration number: CRD42022333411.

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.

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.

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.

Exercise-induced irisin release as a determinant of the metabolic response to exercise training in obese youth: the EXIT trial

The mechanisms underlying the metabolic improvements following aerobic exercise training remain poorly understood. The primary aim of this study was to determine if an adipomyokine, irisin, responded to acute exercise was associated with the metabolic adaptations to chronic aerobic exercise in obese youth. The acute response to exercise was assessed in 11 obese youth following 45‐min acute bouts of aerobic (AE) and resistance exercise (RE). The irisin area under the curve (pre‐exercise, 15, 30, and 45 min) during these AE sessions were the main exposure variables. The primary outcome measure was the change in insulin sensitivity using the Matsuda index, following 6 weeks of RE training, delivered for 45 min, three times per week at 60–65% 1RM. Participants were also categorized as either responders (above) or nonresponders (below) based on the percentage change in the Matsuda index following the 6‐week intervention. Irisin increased significantly during the acute bout of AE from 29.23 ± 6.96 to 39.30 ± 7.05 ng/mL; P = 0.028, but not significantly during the RE session (P = 0.182). Absolute and relative change in irisin during the acute bout of AE was associated with absolute and relative change in Matsuda index (r = 0.68; P = 0.022 and r = 0.63; P = 0.037) following the 6‐week RE intervention. No such association was observed with the irisin response to acute RE (all P > 0.05). Responders to the 6‐week RE intervention displayed a fourfold greater irisin response to acute AE (90.0 ± 28.0% vs. 22.8 ± 18.7%; P = 0.024) compared to nonresponders. Irisin increases significantly following an acute bout of AE, but not RE, and this response is associated with a greater improvement in insulin sensitivity in response to chronic resistance training.

Low muscle mass is associated with metabolic syndrome in Korean adolescents: the Korea National Health and Nutrition Examination Survey 2009-2011

Little is known about the relationship between low muscle mass (LMM) and metabolic risk factors in adolescents. We hypothesized that LMM in adolescents is associated with metabolic syndrome (MetS) and its components in Korean adolescents. This cross-sectional study included 1420 participants (749 males and 671 females), aged 12 to 19 years, who participated in the 2009-2011 Korea National Health and Nutrition Examination Surveys. Appendicular skeletal muscle mass was divided by body weight, and any value below the lower quintile of the study population, according to each age and sex category, was considered to represent LMM. A participant was considered to have MetS if he/she demonstrated at least 3 of the National Cholesterol Education Program-Adult Treatment Panel III criteria. The overall prevalence of MetS was 4.9%, with a prevalence of 7.1% in males and 2.3% in females. Low muscle mass significantly increased the risk of MetS, after adjusting for potential covariates (odds ratio [OR], 5.28; 95% confidence interval, 2.76-10.13). Similarly, the ORs for the MetS components were significantly higher in individuals with LMM than in those without LMM. In the subgroup analysis, LMM was significantly associated with MetS in both adolescent boys and girls. In addition, the adjusted OR was significantly higher in individuals with LMM than in those without, after stratifying the groups by age. In conclusion, our results suggest that adolescents with LMM may have a high risk of MetS. Public health initiatives are needed to develop interventions for preventing and treating LMM in adolescents.

The effects of weekly exercise time on VO2max and resting metabolic rate in normal adults

[Purpose] The present study examined the effect of individual weekly exercise time on resting metabolic rate and VO_2max (maximal oxygen uptake), which are important components of individual health indexes. [Subjects and Methods] Thirty healthy adults participated in this study. Questionnaires were used to divide the participants into groups based on average weekly walking. Resting metabolic rate was measured using a respiratory gas analyzer. Graded exercise tests were conducted using a treadmill, and the modified Bruce protocol was used as an exercise test method. [Results] VO_2max, anaerobic threshold, and resting metabolic rate were significantly different among the groups. [Conclusion] Average weekly exercise time affected VO_2max, resting metabolic rate, and anaerobic threshold, all of which are indicators of individual physical ability and health. These values increased as the individual amount of exercise increased. In addition, VO_2max, resting metabolic rate, and anaerobic threshold were found to be closely correlated. These findings were consistent with the results of similar previous studies.

Multiple components of fitness improved among overweight and obese adolescents following a community-based lifestyle intervention

Fitness is an important component of health, and obese adolescents regularly have poor fitness. Unfortunately, few have assessed the impact of community-based lifestyle interventions on multiple components of fitness. The purpose of this study was to assess the impact of participation in a community-based intervention involving adolescents and parents on multiple components of fitness of obese adolescents. In a within-subject, waitlist controlled clinical trial with 12 months follow-up in Western Australia, participants (n = 56) completed multiple fitness measures at baseline, immediately prior to beginning an 8-week intervention and at 3, 6 and 12 months during a maintenance period. Performance on the shuttle walk was improved immediately post-intervention (increase of 42.8 m, 95% CI: 7.5, 78.2) and at 12 months post-intervention (increase of 44.6 m, 95% CI: 1.3, 87.8) compared with pre-intervention. Muscle performance of quadriceps and deltoids were improved post-intervention (increase of 1.1 (95% CI: 0.1, 2.1) kg · F and 1.0 (0.02, 2.1) kg · F, respectively) and all muscle performance measures were improved at 12 months following the intervention. There were no changes in waist circumference. A community-based lifestyle programme such as Curtin University's Activity, Food and Attitudes Program (CAFAP) may be a viable strategy for improving fitness in overweight adolescents.

[Metabolic effects of exercise on childhood obesity: a current view]

OBJECTIVE

To review the current literature concerning the effects of physical exercise on several metabolic variables related to childhood obesity.

DATA SOURCES

A search was performed in Pubmed/Medline and Web of Science databases. The keywords used were as follows: Obesity, Children Obesity, Childhood Obesity, Exercise and Physical Activity. The online search was based on studies published in English, from April 2010 to December 2013.

DATA SYNTHESIS

Search queries returned 88,393 studies based on the aforementioned keywords; 4,561 studies were selected by crossing chosen keywords. After applying inclusion criteria, four studies were selected from 182 eligible titles. Most studies have found that aerobic and resistance training improves body composition, lipid profile and metabolic and inflammatory status of obese children and adolescents; however, the magnitude of the effects is associated with the type, intensity and duration of practice.

CONCLUSIONS

Regardless of type, physical exercise promotes positive adaptations to childhood obesity, mainly acting to restore cellular and cardiovascular homeostasis, to improve body composition, and to activate metabolism; therefore, physical exercise acts as a co-factor in combating obesity.

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

BACKGROUND

Overweight and obese children and adolescents face many physical and psychosocial hardships. Resistance training is a modality of exercise which allows this at-risk group to excel and therefore has the potential to positively affect not only their physical but also psychosocial health.

OBJECTIVE

To systematically review and meta-analyse the peer-reviewed literature to determine the effect of resistance training on the strength, body composition and psychosocial status of overweight and/or obese children and/or adolescents.

DATA SOURCES

Relevant databases (MEDLINE, Embase, Scopus, Web of Science, SPORTDiscus, CINAHL, PsycINFO, Cochrane library, ProQuest) were searched up to and including 30 January 2013.

STUDY SELECTION

Included studies (n = 40, from the 2,247 identified) were randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs) and uncontrolled trials (UCTs) which had run an exercise intervention, with a resistance training component, for overweight and/or obese children and/or adolescents, and which had examined the effect of resistance training on either strength, body composition or psychosocial outcomes.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies were initially critically appraised for risk of bias by the lead author, following which both co-authors critically appraised five randomly selected studies to assess reliability.

RESULTS

Randomised controlled trials and NRCTs were analysed separately from UCTs. To determine the overall intervention effect for each outcome variable for each study design group, standardised mean differences were calculated with each individual study/data set weighted by the inverse of the pooled variance. The overall intervention effect reported for RCTs and NRCTs was relative to the control group whereas the effect reported for UCTs shows an overall post-intervention effect. Subgroup analyses, which determined whether the overall intervention effect was influenced by intervention type, training volume, age, sex, risk of bias or study design (for RCT/NRCT group only), were run using the same summary measure. Typically, resistance training had very small to small effects on body composition and moderate to large effects on strength in favour of the intervention. However, the magnitude and direction of the effect of resistance training on psychological outcomes are still unclear given the limited number of studies which looked at psychosocial outcomes and the inconclusive results shown by this review. Uncontrolled trials typically showed larger intervention effects than RCTs and NRCTs; however, these results may be greatly influenced by maturational changes rather than the intervention itself.

LIMITATIONS

The included studies employed a number of different exercise intervention types (e.g. resistance training, resistance plus aerobic training etc.) that ranged from 6 to 52 weeks in duration. Studies also employed a number of different methodologies to assess similar outcome measures (e.g. dual energy X-ray absorptiometry versus skinfolds to assess body composition; one-repetition maximum testing versus hand grip strength to assess strength). However, by completing subgroup analyses and using a standardised summary measure these limitations have been accounted for.

CONCLUSION

While the effect of resistance training on the body composition and strength of overweight and obese children and adolescents is clear, given the paucity of conclusive data more studies are needed to fully understand the effect of resistance training on the psychosocial status of this population.

A review of randomized controlled trials of aerobic exercise training on fitness and cardiometabolic risk factors in obese adolescents

Aerobic training is the most prescribed exercise modality for the management of pediatric obesity. There is strong evidence that it decreases waist circumference, percent body fat and visceral fat, increases cardiorespiratory fitness, and decreases blood pressure in obese adolescents. However, the independent effects of aerobic exercise training on other cardiometabolic risk factors (ie, insulin resistance markers, plasma lipid levels, and inflammatory markers) are limited and yield inconsistent findings. Our article reviews randomized controlled trials evaluating the effects of aerobic exercise training on body composition, fitness, lipid levels, and insulin resistance in obese adolescents (aged 13-18 years) and outlines future research directions for this population.