Changes in muscular fitness and its association with blood pressure in adolescents

Association of Initial Muscle Fitness with Weight Loss and Metabolically Healthy Status in Children and Adolescents with Obesity: A Retrospective Study

This retrospective study aimed to investigate the association of initial muscular fitness (MF) with weight loss and metabolic health status in 282 children and adolescents with obesity during 3 to 4 weeks of diet- and exercise-based interventions. Metabolically healthy obesity (MHO) definitions established in 2023 and MF standards based on the 2021 Chinese children's grip strength grading were applied. The proportion of metabolically unhealthy obesity (MUO) was higher in the high MF group than in their low MF counterparts at baseline. After the intervention, neither group transitioned from MUO to MHO due to the high frequency of low HDL-C. High MF females showed a higher percentage of high systolic blood pressure (SBP) than low MF females before and after intervention. High MF males exhibited greater improvements in waist circumference, hip circumference, waist-hip ratio, triglycerides, total cholesterol, and LDL-C than low MF males. The benefits of weight loss and blood lipids obtained by males are more evident than those obtained by females under the same MF level. Thus, attention should be paid to females during weight loss regardless of MF levels. Precision therapy should prioritize the management of blood pressure and avoid excessive reduction in HDL-C levels to sustain metabolic health.

Muscular fitness profiles in relation to the response in body fat during school-based high-intensity intervention

BACKGROUND

We aimed to assess the equivalence of the muscular fitness (MF) between body fat percentage (BFP) responders (RsBFP) and non-responders (NRsBFP) to school-based high-intensity interval training (HIIT). Adolescents aged 16 (N.=73, 42.5% of males) were identified as RsBFP (N.=45) or NRsBFP (N.=28). MF was assessed based on hand strength (HS), abdominal muscle strength (ABS), and leg power (VJ).

METHODS

Profile analysis showed distinct patterns of MF changes in both response categories. Despite the presence of parallelism (Wilks' Λ=0.979, Pillai's V=0.212, P=0.473), a gradient of increasing changes (HS-ABS-VJ) was found in the RsBFP, while a gradient of decreasing changes was shown in the NRsBFP, and a significant level of inequality (F(1,71)=7.823, P=0.047, partial eta-squared [η2p] 0.041).

RESULTS

One-way analysis showed a significant and moderate effect on VJ (F(1,71)=7.080, P=0.010, η2P=0.091), a close to significant effect on ABS (F(1,71)=3.300, P=0.074, η2P=0.044) and lack of an effect on HS (F(1,71)=0.699, P=0.406, η2P=0.010). The test of equal means across the condition categories (separately for RsBFP and NRsBFP) indicated that there was no multivariate statistically significant within-group effect (F(2, 70)=0.517, P=0.599).

CONCLUSIONS

The findings may help teachers assess the potential and indirect changes in muscle performance after employing a body weight intervention (based on the HIIT program). A more targeted approach to treating adolescents with excessive BF, in parallel with improving MF, can be individually tailored.

Role of muscle mass in the association between handgrip strength and blood pressure in children and adolescents

Studies have reported conflicting results on the association between handgrip strength (HGS) and blood pressure during childhood and adolescence. High multicollinearity involving somatic components that influence both HGS and blood pressure might be an important source of bias. This study sought to investigate the independent effects of HGS and muscle mass on blood pressure levels in children and adolescents. Muscle mass and fat mass (Multifrequency Electrical Bioimpedance) and systolic (SBP) and diastolic (DBP) blood pressure (Automatic oscillometric device) were assessed in 833 volunteers aged 6-18 years, of both sexes. Handgrip strength-for-age quartiles were calculated and participants were assigned to groups by HGS quartiles. Analysis of covariance was conducted to address the linear association between HGS and SBP adjusted for height, muscle mass, and fat mass. To test for linear trend, contrast analysis was conducted. Partial eta-squared was used to confirm or rule out a small significant effect of the independent variables on SBP. The effect size of HGS on SBP was not significant in both sexes. In girls, 1.7% of the between-groups variance in SBP was accounted for by muscle mass (P = 0.016). In boys, 2.3% and 1.8% of the between-groups variance in SBP was accounted for by muscle mass (P = 0.001) and height (P = 0.005), respectively. In conclusion, children with a more advanced physical maturity for their age, that is, who are taller, stronger, and have greater fat-free mass, may be nearly reaching the physiological parameters of adulthood, and consequently have higher systolic blood pressure.

Assessment of physical activity among adolescents: a guide to the literature

Purpose

The aim of this article is to systematically review articles and annual reports concerning young peoples' physical activity (PA) and linking this to considerations of the state and national defense.

Method

A systematic search of the literature included an analysis of publications accessible in global databases and other available books, student papers, and projects. The articles and reports were categorized based on year of publication, methods used, age of respondents, sample size, country, and digital object identifier (DOI).

Results

The result of this search is an overview of the extent and manner in which the worldwide scientific community is addressing the current situation and the long-term development of the physical fitness of adolescents. This publication also maps to what extent professional publications and articles are addressing PA from the perspective of the needs of armies and armed forces of various countries around the world.

Conclusions

The article provides a systematic overview of methods used to measure PA, and an overview of articles dealing with assessing PA. The examined articles indicate that from the perspective of not only national defense, but also health and overall quality of life, in particular, we need initiatives to encourage and motivate young people to increase their everyday PA. The research therefore also includes an overview of factors that may considerably influence PA. The results ascertained in this publication will be used, i.a. for investigating a longitudinal defense research project of the Ministry of Defense of the Czech Republic in which the authors are participating.

Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness

BACKGROUND

Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI ≥ 35 kg/m²).

OBJECTIVE

To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample.

METHODS

This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 ± 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45).

RESULTS

The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 ± 0.1 vs. Low-MQI: 0.8 ± 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 ± 17.5 vs. Low-MQI: 140.1 ± 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 ± 5.9 vs. Low-MQI; 22.4 ± 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (β: -0.07, p = 0.011), SBP (β: -18.47, p = 0.001), and CRF (β: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP.

CONCLUSIONS

MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2_max). It mediates the relationship between abdominal obesity and SBP.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Physical fitness mediates and predicts for high blood pressure among children in relation to weight status

Background

Pediatric hypertension contributes to adulthood hypertension and target organ damage. Obesity is a well-known predictor for pediatric hypertension; however, the relationship between physical fitness and blood pressure (BP) is unclear among children. This study aimed to compare the differences in demographics, anthropometrics, and physical fitness across BP subgroups and investigate whether physical fitness was related to pediatric hypertension independent of weight status.

Methods

This quantitative, cross-sectional study investigated demographic, anthropometric, physical fitness, and BP measures among 360 healthy school-aged children. Continuous variables were compared across BP subgroups with the one-way analysis of variance. Mediation and moderation analyses were used to explore the mechanism. Multivariable regression models were used to assess independent associations for hypertension.

Results

There were 177 (49.2%), 37 (10.3%), and 146 (40.6%) children in the normotensive, elevated BP, and hypertensive subgroups, respectively. The hypertensive subgroup had higher body mass index (BMI) and waist/height ratio percentiles and performed worse in 800-m run, standing long jump (SLJ), and 1-min sit-ups than the normotensive subgroup. Furthermore, the 800-m run percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) and sit and reach percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) mediated the relationship between the BMI percentile and systolic BP percentile; the SLJ percentile was directly associated with the diastolic BP percentile (β,-0.197, 95% confidence interval,-0.298-0.097; p < 0.001). The parsimonious model of multivariable regression models revealed that the SLJ percentile (adjusted exp (β), 0.992, 95% confidence interval, 0.985-0.999; p = 0.042) and BMI percentile (adjusted exp (β), 1.024, 95% confidence interval, 1.016-1.032; p < 0.001) were two independent predictors for pediatric hypertension.

Conclusion

Physical fitness mediates the relationship between anthropometric and BP measures. The SLJ percentile is associated with pediatric hypertension independent of the BMI percentile. Proactive screening and health promotion for not only healthy weight status but also good physical fitness may be beneficial for BP control among school-aged students.

A Better Cardiopulmonary Fitness Is Associated with Improved Concentration Level and Health-Related Quality of Life in Primary School Children

This study aimed to examine the physical fitness (PF) levels of primary school children and to determine the associations among PF, concentration, and health-related quality of life (HRQOL) in a subcohort. PF was assessed in 6533 healthy primary school-age children (aged 6−10 years, 3248 boys and 3285 girls) via standardized test batteries. Concentration was measured with the d2-R test, and KINDL questionnaires were used to determine HRQOL. Analysis of variance showed an increase in PF with age in all PF dimensions (all p < 0.001), except cardiopulmonary fitness (estimated VO2max) in girls (p = 0.129). Boys performed better in nearly all PF dimensions, except curl-ups, in all children aged ≥7 years (p < 0.05). Concentration levels increased in boys and girls aged 7−9 years (p < 0.001), whereas HRQOL did not (p = 0.179). The estimated VO2max had a strong impact on concentration (β = 0.16, p < 0.001) and HRQOL (β = 0.21, p < 0.001) in 9- to 10-year-olds. Cardiopulmonary fitness is important for improved concentration and better HRQOL in primary school-age children. However, longitudinal data are needed to provide further insight into the intraindividual relationships of PF and concentration over the course of child development and set up targeted prevention programs.

Sex Moderated Mediation of the Musculoskeletal Fitness in Relationship between High-Intensive Interval Training Performing during Physical Education Classes and Cardiorespiratory Fitness in Healthy Boys and Girls

High-intensive interval training (HIIT) is indicated as a means of improving cardiorespiratory fitness (CRF) and musculoskeletal fitness (MSF). The relationship between CRF and MSF was examined too. Little is known about gaining CRF from HIIT independence of MSF in adolescents. Therefore, this study is aimed at investigating whether MSF mediated the relationship between HIIT and CRF and whether sex moderate this relation. The study sample included 122 individuals (45 boys, 77 girls) 16.12 ± 0.38 years of secondary school age. Participants were assigned to the HIIT intervention or control groups. The intervention lasted 14 minutes during one physical education lesson per week for ten weeks. Outcome and potential mediator were residual changes calculated from pre- and postintervention results of MSF components: handgrip (HG), sit-ups (ABS), sit-and-reach (FL), vertical jump (VJ), and Harvard step-test representing cardiorespiratory fitness (CRF). MSF index (MSFI) was calculated as a construct, agglomerating all MSF, and tested its usefulness. HIIT significantly impacted CRF in boys and girls (B = 2.32, p = 0.032; B = 2.28, p = 0.005, respectively). The impact of the HIIT program on the ABS and FL was observed only in girls. The moderation effect of sex was confirmed. Significant effect of HIIT on CRF decreased (B_direct < B_total) and was no significant after including FL (B = 1.46, p = 0.62)—complete mediation, but no ABS (B = 2.97, p = 0.001)—partial mediation. CRF was mediated by changes in ABS (B = 2.28, p < 0.001) and FL (4.18, p < 0.001). MSFI was not mediating; its usefulness was limited. HIIT is an effective tool in the development of CRF in both sexes. MSF played a limited role in the relationship between HIIT and CRF. It suggested different mechanisms in both sexes: girls who performed better to the HIIT had better values of FL and ABS, but not boys. HIIT intervention involved modifications in ABS or FL, which also influenced the increase of CRF.

Muscular Fitness and Cardiometabolic Variables in Children and Adolescents: A Systematic Review

BACKGROUND

The importance of muscular fitness (MF) in the performance of activities of daily living is unequivocal. Additionally, emerging evidence has shown MF can reduce cardiometabolic risk in children and adolescents.

OBJECTIVES

The purpose of this study was to examine and summarize the evidence regarding the relationship between MF phenotypes (i.e., maximum muscular strength/power, muscular endurance, and maximum muscular strength/power/endurance) and cardiometabolic variables (obesity, blood pressure, lipids, glucose homeostasis, inflammatory markers, and clustered cardiometabolic variables) in children and adolescents.

DESIGN

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered with PROSPERO, number CRD42020179273.

DATA SOURCES

A systematic review was performed on five databases (PubMed, EMBASE, SciELO, Scopus, and Web of Knowledge) from database inception to May 2020, with complementary searches in reference lists.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligibility criteria included (1) a study sample of youth aged ≤ 19 years, (2) an assessment of MF with individual or clustered cardiometabolic variables derived from adjusted models (regardless of test/measurement adopted or direction of reported association), and (3) a report of the association between both, using observational studies. Only original articles published in peer-reviewed journals in English, Portuguese, and Spanish languages were considered. The quality of the included studies was assessed by using the National Heart, Lung, and Blood Institute checklist. The percentage of results reporting a statistically significant inverse association between each MF phenotype and cardiometabolic variables was calculated.

RESULTS

Of the 23,686 articles initially identified, 96 were included (77 cross-sectional and 19 longitudinal), with data from children and adolescents from 35 countries. The score for the quality of evidence ranged from 0.33 to 0.92 (1.00 maximum). MF assessed by maximum muscular strength/power was inversely associated with lower obesity (64/113 total results (56.6%)) and reduction in clustered cardiometabolic risk (28/48 total results (58.3%)). When assessed by muscular endurance, an inverse association with obesity (30/44 total results (68.1%)) and cardiometabolic risk (5/8 total results (62.5%)) was identified. Most of the results for the relationship between MF phenotypes with blood pressure, lipids, glucose homeostasis, and inflammatory markers indicated a paucity of evidence for these interrelationships (percentage of results below 50.0%).

CONCLUSION

MF assessed by maximum muscular strength/power or muscular endurance is potentially associated with lower obesity and lower risk related to clustered cardiometabolic variables in children and adolescents. There is limited support for an inverse association between MF with blood pressure, lipids, glucose homeostasis biomarkers, and inflammatory markers in children and adolescents.

Body muscle gain and markers of cardiovascular disease susceptibility in young adulthood: A cohort study

BACKGROUND

The potential benefits of gaining body muscle for cardiovascular disease (CVD) susceptibility, and how these compare with the potential harms of gaining body fat, are unknown. We compared associations of early life changes in body lean mass and handgrip strength versus body fat mass with atherogenic traits measured in young adulthood.

METHODS AND FINDINGS

Data were from 3,227 offspring of the Avon Longitudinal Study of Parents and Children (39% male; recruited in 1991-1992). Limb lean and total fat mass indices (kg/m2) were measured using dual-energy X-ray absorptiometry scans performed at age 10, 13, 18, and 25 y (across clinics occurring from 2001-2003 to 2015-2017). Handgrip strength was measured at 12 and 25 y, expressed as maximum grip (kg or lb/in2) and relative grip (maximum grip/weight in kilograms). Linear regression models were used to examine associations of change in standardised measures of these exposures across different stages of body development with 228 cardiometabolic traits measured at age 25 y including blood pressure, fasting insulin, and metabolomics-derived apolipoprotein B lipids. SD-unit gain in limb lean mass index from 10 to 25 y was positively associated with atherogenic traits including very-low-density lipoprotein (VLDL) triglycerides. This pattern was limited to lean gain in legs, whereas lean gain in arms was inversely associated with traits including VLDL triglycerides, insulin, and glycoprotein acetyls, and was also positively associated with creatinine (a muscle product and positive control). Furthermore, this pattern for arm lean mass index was specific to SD-unit gains occurring between 13 and 18 y, e.g., -0.13 SD (95% CI -0.22, -0.04) for VLDL triglycerides. Changes in maximum and relative grip from 12 to 25 y were both positively associated with creatinine, but only change in relative grip was also inversely associated with atherogenic traits, e.g., -0.12 SD (95% CI -0.18, -0.06) for VLDL triglycerides per SD-unit gain. Change in fat mass index from 10 to 25 y was more strongly associated with atherogenic traits including VLDL triglycerides, at 0.45 SD (95% CI 0.39, 0.52); these estimates were directionally consistent across sub-periods, with larger effect sizes with more recent gains. Associations of lean, grip, and fat measures with traits were more pronounced among males. Study limitations include potential residual confounding of observational estimates, including by ectopic fat within muscle, and the absence of grip measures in adolescence for estimates of grip change over sub-periods.

CONCLUSIONS

In this study, we found that muscle strengthening, as indicated by grip strength gain, was weakly associated with lower atherogenic trait levels in young adulthood, at a smaller magnitude than unfavourable associations of fat mass gain. Associations of muscle mass gain with such traits appear to be smaller and limited to gains occurring in adolescence. These results suggest that body muscle is less robustly associated with markers of CVD susceptibility than body fat and may therefore be a lower-priority intervention target.

Improvements in Physical Fitness are Associated with Favorable Changes in Blood Lipid Concentrations in Children

Although accumulating evidence suggests the benefits of cardiorespiratory fitness and muscular fitness, little knowledge exists on how other physical fitness (PF) components are associated with cardiovascular disease (CVD) risk markers in children. Additionally, much of the relevant evidence is from longitudinal studies with CVD risk markers at a single time point (i.e., baseline) rather than changes in PF. The purpose of the present study was to examine whether initial 1-year changes in different performance measures of PF (i.e., endurance performance, muscular strength/endurance, flexibility, agility, and speed) can predict the subsequent changes (2-year change) in blood lipid concentrations in children. This 2-year longitudinal study included a total of 251 Japanese children (mean age 9.2 ± 0.4). PF tests were performed to comprehensively evaluate the participant's fitness levels (handgrip strength [upper body muscular strength], bent-leg sit-ups [muscular endurance], sit-and-reach [flexibility], side-step [agility], 20-meter shuttle run [endurance performance], 50-meter sprint [speed], standing long jump [lower body muscular strength], and softball throw [explosive arm strength and throwing ability]). Fasting lipid profile was assayed for triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and non-HDL-C concentration. Multilevel linear regressions were used to examine the associations between the preceding changes (over 1-year) in PF and subsequent changes (over 2-years) in blood lipid concentrations. We also examined the simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. For boys, preceding improvement in handgrip strength was negatively associated with TG concentration (β = -0.260, p = 0.030); improvements in bent-leg sit-ups were negatively associated with clustered lipid scores (β = -0.301, p = 0.038) and non-HDL-C (β = -0.310, p = 0.044); and improvements in 50m sprinting were associated with subsequent changes in non-HDL-C (β = 0.348, p = 0.006) and LDL-C (β = 0.408, p = 0.001). For girls, improvements in handgrip strength was negatively associated with TG concentration (β = -0.306, p = 0.017); and improvements in standing long jump were negatively associated with non-HDL-C (β = -0.269, p = 0.021) and LDL-C (β = -0.275, p = 0.019). For boys and girls, there were no significant simultaneous associations between 2-year changes in PF and 2-year changes in blood lipid concentrations. In conclusion, preceding change in physical fitness in relation to change in blood lipid concentration likely reflect a physiological adaptation to growth and maturation since these associations diminished in the subsequent year.

Fitness, waist circumference and their association with future blood pressure in youth: The UP&DOWN Longitudinal Study

OBJECTIVES

The aim was to determine the independent associations of muscular fitness (MF), cardiorespiratory fitness (CRF) and waist circumference (WC) with blood pressure (BP) levels over 2 years in children and adolescents.

METHODS

1089 children (517 females) and 787 adolescents (378 females) with complete data on fitness, WC and BP (systolic [SBP] and diastolic [DBP]) were included. Upper MF was assessed through the handgrip strength test, and lower MF using the standing long jump test. The 20-m shuttle run test was used to assess CRF. WC was obtained following standardized methods. Different regression models were fitted by introducing fitness and WC at baseline and their changes as exposures and BP at follow-up and their changes as outcomes.

RESULTS

WC at baseline was positively and independently associated with each BP variable at follow-up in children and adolescents (β=0.094-0.260; p≤0.05), and CRF was negatively associated with DBP in adolescents (β=-0.096; p=0.034). WC changes were associated with BP variables 2 years later in children (β=0.121-0.142; p<0.01). In adolescents, changes in upper MF (β=-0.116; p=0.001) and WC (β=0.080-0.098; p<0.05) were associated with SBP at follow-up. WC changes were independently associated with changes in each BP variable in children (β=0.111-0.145; all p<0.05) and SBP changes in adolescents (β=0.103 to 0.117; all p<0.01).

CONCLUSIONS

WC, but neither MF nor CRF, is independently associated with BP and its changes over 2 years. The attainment or maintenance of optimal fatness levels in the pediatric population should be highly encouraged for the prevention of future hypertension.

Clustering of 24-h movement behaviors associated with cardiorespiratory fitness among adolescents: a latent class analysis

This study aimed to examine the clustering of 24-h movement behaviors (moderate to vigorous physical activity, screen time, and sleep duration) and their association with cardiorespiratory fitness among adolescents. We evaluated 561 adolescents (52.1% girls; mean age, 13.0 ± 1.0 years) from Florianópolis, Brazil. A 20-m shuttle run was used to assess cardiorespiratory fitness, while a questionnaire was used to measure 24-h movement behaviors. A latent class analysis was performed to identify the clustering of 24-h movement behaviors, while linear Bayesian mixed-effect regression models were applied to identify their association with cardiorespiratory fitness. Two classes were identified: unhealthy (10.4%), characterized as a high probability of practicing less than 300 min/week of moderate to vigorous physical activity, spending more than 4 h/day in front of screens, and sleeping less than 8 h/day; and healthy (89.6%), characterized by a high probability of practicing more than 420 min/week of moderate to vigorous physical activity, spending less than 2 h/day in front of screens, and sleeping 8-10 h/day. Adolescents in the healthy class had a higher cardiorespiratory fitness level than those in the unhealthy class. Most adolescents were grouped in the healthy class and had higher cardiorespiratory fitness levels than those in the unhealthy class. These results suggest that families and professionals should work toward creating healthier lifestyles for adolescents by increasing opportunities to practice moderate to vigorous physical activity, reduce screen time, and favor healthy sleep to increase their cardiorespiratory fitness levels. What is Known: • Moderate to vigorous physical activity, screen time, and sleep duration are positively, negatively, and inconsistently associated with cardiorespiratory fitness, respectively, when analyzed separately. • Little is known about the clustering of 24-h movement behaviors and how they are associated with cardiorespiratory fitness levels in adolescents. What is New: • The 24-h movement behaviors clustered into almost opposite classes among adolescents (healthy and unhealthy classes). • Adolescents in the healthy class had greater cardiorespiratory fitness levels than those in the unhealthy class.

Bipedal hopping as a new measure to detect subtle sensorimotor impairment in people with multiple sclerosis

BACKGROUND

Bipedal hopping has the potential to detect subtle multiple sclerosis (MS)-related impairments, especially among patients who "pass" typical movement tests. In this narrative review, we outline the biomechanics of bipedal hopping and propose its usefulness as a novel outcome measure for people with MS having mild disability.

METHODS

We summarize articles that (1) examined the biomechanics of jumping or hopping and (2) tested the validity and/or reliability of hopping tests. We consolidated consistencies and gaps in research and opportunities for future development of the bipedal hop test.

RESULTS

Bipedal hopping requires immense power, coordination, balance, and ability to reduce co-contraction; movement components typically affected by MS. These impairments can be measured and differentiated by examining specific variables, such as hop length (power), symmetry (coordination), center of pressure (balance), and coefficient of variability (co-contraction/spasticity). Bipedal hopping challenges these aspects of movement and exposes sensorimotor impairments that may not have been apparent during walking.

CONCLUSIONS

Testing of bipedal hopping on an instrumented walkway may detect and monitor sensorimotor control in people with MS who do not currently present with clinical deficits. Early measurement is imperative for precise rehabilitation prescription to slow disability progression prior to onset of measurable gait impairment.Implications for rehabilitationJumping and hopping tests detect lower limb and balance impairments in children, athletes, and older adults.Bipedal hop test measures multiple domains: power, coordination, balance, and muscle timing.Bipedal hop test may expose subtle sensorimotor impairments in people with multiple sclerosis.Multiple variables measured can discern type of sensorimotor impairment to direct personalized rehabilitation programs.

Hypertensive Measures In Schoolchildren: Risk Of Central Obesity And Protective Effect Of Moderate-To-Vigorous Physical Activity

Background The proportion of arterial hypertension (AH) has increased in children and adolescents and is associated with several comorbidities. Objective To verify the association of arterial hypertension with central and general obesity as well as according to the level of physical activity in schoolchildren. Methods 336 children and adolescents aged 11 to 17 participated in the study. Height, body weight, waist circumference (WC) and blood pressure (BP) were measured. The body mass index z-score (BMI-z) was calculated. The level of physical activity was assessed by the short form of the International Physical Activity Questionnaire (IPAQ) according to the practice of moderate-to-vigorous physical activities (AF-mv). Students with systolic (SBP) and/or diastolic blood pressure (DBP) higher than the 95thpercentile according to sex, age and height or ≥120/80 were considered hypertensive. Statistical tests of t-Student, Chi-square, Mann-Whitney and binary logistic regression model were used, considering the significance level of p<0.05. Results It was found that 40.5% of the students had AH, 35.11% were overweight (12.5% obese), 13.39% had high WC and 40.2% were considered insufficiently active in AF-mv. The chances of AH were related to high WC (OR = 6.11; 95% CI: 2.59¬-14.42) and overweight (OR = 2.91; 95% CI: 1.76-4.79). In addition, adolescents who practiced AF-mv had a lower risk of high DBP (OR = 0.33; 95% CI: 0.15-0.72). Conclusion Central obesity was the best predictor of AH in children and adolescents, as well as general obesity and males. The practice of AF-mv demonstrated a protective effect on high DBP in schoolchildren. (Arq Bras Cardiol. 2020; 115(1):42-49).

Is Muscular Fitness Associated with Future Health Benefits in Children and Adolescents? A Systematic Review and Meta-Analysis of Longitudinal Studies

BACKGROUND

No previous systematic review has quantitatively examined the association between muscular fitness during childhood and adolescence and health parameters later in life.

OBJECTIVE

The aim was to systematically review and meta-analyze the current evidence for a prospective association between muscular fitness in childhood and adolescence and future health status.

METHODS

Two authors systematically searched MEDLINE, EMBASE and SPORTDiscus electronic databases and conducted manual searching of reference lists of selected articles. Relevant articles were identified by the following criteria: apparently healthy children and adolescents aged 3-18 years with muscular fitness assessed at baseline (e.g., handgrip, standing long jump, sit-ups, among others), and a follow-up period of ≥ 1 year. The outcome measures were anthropometric and adiposity measurements and cardiometabolic, bone and musculoskeletal health parameters. Two authors independently extracted data.

RESULTS

Thirty studies were included in the meta-analysis, yielding a total of 21,686 participants. The meta-analysis found a significant, moderate-large (p < 0.05) effect size between muscular fitness at baseline and body mass index (r = - 0.14; 95% confidence interval (CI) - 0.21 to - 0.07), skinfold thickness (r = - 0.32; 95% CI - 0.40 to - 0.23), homeostasis model assessment estimated insulin resistance (r = - 0.10; 95% CI - 0.16 to - 0.05), triglycerides (r = - 0.22; 95% CI - 0.30 to - 0.13), cardiovascular disease risk score (r = - 0.29; 95% CI - 0.39 to - 0.18), and bone mineral density (r = 0.166; 95% CI 0.086 to 0.243) at follow-up.

CONCLUSION

A prospective negative association was observed between muscular fitness in childhood/adolescence and adiposity and cardiometabolic parameters in later life, together with a positive association for bone health. There is inconclusive evidence for low back pain benefits.

Muscular fitness and cardiorespiratory fitness are associated with health-related quality of life: Results from labmed physical activity study

BACKGROUND

Adolescents' physical fitness levels are an important indicator of their lifestyle and seem to have positive consequences in health-related quality of life (HRQoL).

OBJECTIVE

The purpose of this study is to analyse the combined associations of cardiorespiratory fitness and muscular fitness with HRQoL and to assess the differences between HRQoL scores across groups of cardiorespiratory fitness and muscular fitness in Portuguese adolescents.

DESIGN

This is a cross-sectional analysis with 567 Portuguese adolescents aged 12-18 years-old.

METHODS

HRQoL was measured using the Kidscreen-10 questionnaire. Cardiorespiratory fitness was estimated with the 20-m shuttle-run test. Muscular fitness was evaluated using the handgrip and the standing long jump tests and a muscular fitness index was computed by means of standardized measures of both tests. Socioeconomic status was assessed using the Family Affluence Scale. Body composition (body mass and height) was measured according to standard protocols. Accelerometers were used to obtain objective physical activity time. Pubertal stage was assessed using Tanner stages. Adherence to the Mediterranean diet was assessed using the KIDMED index. Participants were divided into four groups based on low or high values of both cardiorespiratory and muscular fitness. Regression analysis, mediation analysis and ANCOVA were performed.

RESULTS

HRQoL was positively associated with cardiorespiratory fitness (B = 0.112; p < 0.05) and muscular fitness score (B = 0.328 p < 0.05), after controlling for potential confounders. However, when both fitness variables were entered in the same model only cardiorespiratory fitness remained significantly associated with HRQoL (B = 0.093 p < 0.05). Cardiorespiratory fitness acted as a full mediator variable on the relationship between muscular fitness and HRQoL in adolescents (p < 0.05). ANCOVA showed that adolescents with high cardiorespiratory fitness/high muscular fitness exhibit better HRQoL scores when compared to those with low muscular fitness/low cardiorespiratory fitness and with those with low muscular fitness/high cardiorespiratory fitness (p < 0.05).

CONCLUSIONS

In adolescents, the combination of high cardiorespiratory fitness and high muscular fitness was positively associated with a better HRQoL.