Reduction in blood pressure and metabolic profile in overweight hypertensive boys participating in a 12-week aerobic exercise program.

Strategies for controlling hypertension include reducing excess fat and increasing muscle mass. However, the effects of exercise interventions on hypertension in adolescents have been little investigated. The purpose was to evaluate the effect of 12 weeks of aerobic exercise on systolic blood pressure (SBP) and diastolic blood pressure (DBP) and the cardiometabolic profile of overweight hypertensive and non-hypertensive boys. The sample included 107 boys diagnosed as overweight, aged between 12 and 17, divided into two non-hypertension groups, one control (GCN, n = 14) and one with exercise (GEN, n = 55), as well as two groups of hypertensives, one control (GCH, n = 12) and one with exercise (GEH, n = 26). The boys were assessed at the study baseline and after 12 weeks in terms of anthropometric parameters, biological maturation, SBP, DBP and mean blood pressure (MBP), lipid, and metabolic profile. The aerobic training programs lasted 12 weeks and were carried out in three weekly sessions at different intensities. The high-intensity interval training session lasted around 35 min at an intensity of 80-100% of the reserve heart rate, and the moderate-intensity of continuous training session lasted 60 min at an intensity of 35-75% of the reserve heart rate. Caloric expenditure was equivalent between the exercises (p = 0.388). CGN and CGH participated only in school physical activities. Repeated measures analysis of variance and clinical effect analysis using Cohen's effect size were used, with a significance level established at p < 0.05. After 12 weeks, all groups increased their height (p < 0.05), but only the exercise groups showed a reduction in anthropometric variables (p < 0.05), with a possibly beneficial effect in GEN (d = - 0.203; p = 0.003). No differences were found in the variables for the GCN. The GCH and GEH groups reduced SBP (p < 0.05), but only GEH showed a reduction in DBP (p = 0.005) and MBP (p = 0.001). In relation to the lipid profile, GEH maintained HDL-c close to baseline values, while GCH showed a reduction in HDL-c (p = 0.021). Regarding the clinical effect of exercise on hypertension, GEH showed a large and very beneficial effect size on DBP (d = - 0.916; p = 0.006) and MBP (d = - 0.926; p = 0.005).Conclusion: Hypertensive boys who practiced physical exercise showed greater effects in reducing blood pressure, indicating the importance of non-drug therapeutic management in overweight adolescents.Trial registration:Brazilian Registry of Clinical Trials RBR-4v6h7b / RBR-6343y7.

Resistance training presents beneficial effects on bone development of adolescents engaged in swimming but not in impact sports: ABCD Growth Study.

BACKGROUND: Sports practice during adolescence is important to enhance bone development, although it may provide different effects depending on the mechanical impact present in the sport. Besides, resistance training (RT) may also induce bone changes directly (via muscle contractions) and indirectly (via myokines). However, there have been no studies analyzing the longitudinal influence of engaging in sport with and without added mechanical load. Thus, this study aims to analyze the combined effects of sports participation and resistance training on areal bone mineral density (aBMD) accrual in adolescent athletes participating in swimming and impact sports for 12-months. METHODS: This was a 12-month longitudinal study. The sample comprised 91 adolescents (21 females) aged 10 to 18 years, engaged in impact sports (basketball, tennis, track & field, baseball and gymnastics, n = 66) and non-impact sport (swimming, n = 25). The sample was divided according to resistance training participation: impact sports only (n = 45), impact sports + resistance training (n = 21), swimming-only (n = 17) and swimming + resistance training (n = 8). aBMD and soft tissues were measured using dual-energy X-ray absorptiometry. Generalized linear models analysis was used for the resistance training (RT) x type of sport interaction in predicting aBMD changes overtime, adjusting for maturation, sex and baseline aBMD. RESULTS: After 12-months, all groups showed a significant increase in aBMD, except for the swimming groups (regardless of resistant training), which showed a significant loss in spine aBMD (-0.045 [-0.085 to -0.004] g/cm2 in swimming-only and - 0.047 [-0.073 to -0.021] g/cm2 in swimming + RT). In comparisons between groups, only swimming + RT group, compared with swimming-only group presented higher upper limbs aBMD (0.096 g/cm2 [0.074 to 0.118] in swimming + RT vs. 0.046 [0.032 to 0.060] g/cm2 in swimming only; p < 0.05) and whole body less head (WBLH) aBMD (0.039 [0.024 to 0.054] g/cm2 in swimming + RT vs. 0.017 [0.007 to 0.027] g/cm2 swimming-only; p < 0.05). CONCLUSION: Despite the significant gain in aBMD in all groups and body sites after 12-months, except for the spine site of swimmers, the results indicate that participation in RT seems to improve aBMD accrual in swimmers at the upper limbs and WBLH.

Ages at peak height velocity in male soccer players 11-16 years: relationships with skeletal age and comparisons among longitudinal studies.

Estimated ages at take-off (TO) and at peak height velocity (PHV) based on two models and maturity status based upon age at PHV and skeletal age (SA) were compared in a longitudinal sample of male soccer players. In addition, estimated ages at PHV in 13 longitudinal samples of soccer players were compared. The longitudinal height records of 58 players of European ancestry, measured annually on four or five occasions between 11 and 16 years, were modeled with Superimposition by Translation and Rotation (SITAR) and Functional Principal Component Analysis (FPCA) to estimate ages at TO and PHV. SAs were assessed with the Fels method. Ages at PHV in 13 longitudinal samples of soccer players (Europe 7, Japan 6) were evaluated with meta-analysis. Estimated ages at TO, 11.2 ± 0.8 (SITAR) and 11.0 ± 0.8 (FCPA) years, and at PHV, 13.6 ± 0.9 (SITAR) and 13.7 ± 0.0 (FCPA) years, were similar. An earlier age at PHV was associated with advanced skeletal maturity status (rho = -0.77 at ~14 years). Ages at PHV among European players indicated a north (later) - south (earlier) gradient, and were later than ages at PHV among Japanese players. In summary, ages at TO and PHV were similar with SITAR and FPCA, and ages at PHV were most strongly correlated with SA at ~14 years. Mean ages at PHV showed a north-south gradient among European samples, and were later compared to Japanese samples.

Training stress, neuromuscular fatigue and well-being in volleyball: a systematic review.

BACKGROUND: Volleyball, with its unique calendar structure, presents distinct challenges in training and competition scheduling. Like many team sports, volleyball features an unconventional schedule with brief off-season and pre-season phases, juxtaposed against an extensive in-season phase characterized by a high density of matches and training. This compact calendar necessitates careful management of training loads and recovery periods. The effectiveness of this management is a critical factor, influencing the overall performance and success of volleyball teams. In this review, we explore the associations between training stress measures, fatigue, and well-being assessments within this context, to better inform future research and practice. METHODS: A systematic literature search was conducted in databases including PsycINFO, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Scopus. Inclusion criteria were original research papers published in peer-reviewed journals involving volleyball athletes. RESULTS: Of the 2535 studies identified, 31 were thoroughly analysed. From these 31 articles, 22 included professional athletes, seven included collegiate-level volleyball athletes, and two included young athletes. Nine studies had female volleyball players, while the remaining 22 had male volleyball athletes. CONCLUSIONS: Internal training load should be collected daily after training sessions and matches with the session rating of perceived exertion method. External training load should also be measured daily according to the methods based on jump height, jump count, and kinetic energy. If force platforms are available, neuromuscular fatigue can be assessed weekly using the FT:CT ratio of a countermovement jump or, in cases where force platforms are not available, the average jump height can also be used. Finally, the Hooper Index has been shown to be a measure of overall wellness, fatigue, stress, muscle soreness, mood, and sleep quality in volleyball when used daily.

Examining the mediating role of muscle quantity in adolescents: associations with adiposity, cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors.

The aim of this study was to evaluate the mediation role of muscle quantity in the relationship between physical fitness and cardiometabolic risk factors (CMRF) in adolescents. This cross-sectional study conducted with 120 adolescents of both sexes, aged between 10 and 17 years. Body mass, height, fat mass (FM), lean mass, blood pressure, high-density lipoprotein, low-density lipoprotein, triglycerides, glucose, insulin, cardiorespiratory fitness (CRF) and 1 repetition maximum strength (1-RM) with evaluation of the leg press 45° (RM-leg), bench press (RM-bench) and arm curl (RM-arm). Body mass index z-score, appendicular skeletal muscle mass, appendicular skeletal muscle mass index, lean mass index (LMI), muscle-to-fat ratio (MFR), age at peak height velocity, and CMRF z-score were calculated. The direct relation between FM and CMRF was mediated by the LMI (26%) and inverse relation between CRF and CMRF was mediated by the LMI (26%). For girls, the direct relation between FM and CMRF was mediated by the LMI (32%); the inverse relation between CRF, RM-leg, RM-arm and CMRF was mediated by the LMI (32%, 33%, and 32%, respective). For boys, the indirect effect was not significant, indicating that LMI is not a mediator in the relation between FM, CRF, 1-RM with CMRF. The direct relation between RM-leg and CMRF was mediated by the MRF (16%). This finding evidenced the importance of promoting a healthy lifestyle to improve physical fitness levels and the quantity of muscle mass in adolescents.

From data to action: a scoping review of wearable technologies and biomechanical assessments informing injury prevention strategies in sport.

BACKGROUND: The purpose of this scoping review was to evaluate the current use of technologies in sports settings for training adaptation and injury prevention. The review aimed to map the existing literature, identify key concepts and themes, and highlight gaps in research, thus offering guidance for future studies. METHODS: This study followed the guidelines of the PRISMA extension for scoping reviews and a search in four major databases was conducted. RESULTS: A total of 21 studies were included. The findings highlighted the widespread use of various technologies, including wearable devices and force plates, to monitor athletes' performance and inform evidence-based decision-making in training and injury prevention. Variables such as Player Load, changes of direction, and acute chronic workload ratio were identified as key metrics in injury prediction. CONCLUSIONS: This review uncovers a dynamic field of research in athlete injury prevention, emphasizing the extensive use of varied technologies. A key finding is the pivotal role of Player Load data, which offers nuanced insights for customizing training loads according to sport-specific demands, player positions, and the physical requirements of various activities. Additionally, the review sheds light on the utility of tools like force plates in assessing fatigue, aiding recovery, and steering injury rehabilitation, particularly in sports prone to knee and ankle injuries. These insights not only enhance our understanding of injury prevention but also provide a strategic direction for future research, aiming to boost athlete safety, performance, and career longevity.

A kinematic analysis of the basketball shot performance: impact of distance variation to the basket.

PURPOSE: The aim of the current study was to examine the variation on the kinematic parameters in the basketball shot associated with the shooting distance. METHODS: Twenty-seven female adolescent basketball players aged 12.1 ± 0.9 years completed 10 BS trials from a frontal position of 4.75 m and 5.75 m from the basket. Nine anatomical markers were placed on the participants' dominant side to assess the kinematic variables. The following variables were analyzed: angle, velocity, and height at ball release; centre of mass horizontal displacement and maximum height attained; maximum hip height and hip height at release; shoulder, elbow, and knee angular position and velocity at ball release; deepest knee flexion during the preparatory phase; the peak of the angular velocity of the shoulder, elbow, and knee joints. RESULTS: At release, the angle decreased while velocity increased significantly at 5.75 m. During the release, greater shoulder flexion and increased joint (shoulder and knee) angular velocity were observed. The deepest knee flexion and the centre of mass horizontal dis- placement were accentuated at 5.75 m. The ball release occurred before the peak of the jump phase. CONCLUSIONS: To compensate for the long ball trajectory to the basket, participants perform a set of adjustments in the body segmental organization to increase the ball veloc- ity at release. The coaches' feedback should focus on the shooting arm's positioning and in the jump phase (to jump as close to vertical as possible). Also, a consistent shooting technique should be acquired close to the basket before expanding the shooting range.

Excess adiposity and low physical fitness hamper Supine-to-Stand test performance among sedentary adolescents

Abstract Objective: The aim of this study was to analyze the relationship between body adiposity and physical fitness with performance in the Supine-to-Stand test (STS-test) in sedentary adolescents. Methods: Sixty-two adolescents, of both sexes, between 10 and 16 years old, participated in the study. Body mass (BM), height, waist circumference (WC), fat mass (FM), fat-free mass (FFM), right and left handgrip strength (HGS-right, HGS-left), abdominal resistance (ABDO), flexibility (FLEX), and cardiorespiratory fitness (VO2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), tri-ponderal mass index (TMI) and waist-to-height ratio (WHtR) were calculated. The STS-test was applied to evaluate the STS-MC by the movement patterns in the execution of the test. The STS-time in seconds (s) was categorized into terciles: fast (FG < 2.0 s), intermediate (IG = 2.0-2.6 s) and slow (SG > 2.6 s). One-way ANOVA, Chi-square, Spearman's correlation coefficient as well as non-parametric tests were used, with significance p 0.05. Results: The SG presented higher BMI, BMI-z, TMI, WHtR, FM, %FM, as well as lower averages for %FFM, HGS-right, HGS-left, FLEX, ABDO, VO2peak, VO2peak relative to BM (VO2peakBM) in relation to GF. The BMI, BMI-z, TMI, WC, WHtR and FM showed moderate and direct correlations with STS-time and inverse with STS-MC (p < 0.01). HGS-right, HGS-left, ABDO, and VO2peakBM showed moderate and an inverse correlation with STS-time (p < 0.05). The VO2peakBM was moderate and with direct correlations to STS-MC (p < 0.01). Conclusion: It is concluded that excess fat and low physical fitness hamper STS-test performance. Therefore, the STS-test can be used for screening students to assess MC.

Physiological profile of adult male long-distance trail runners: variations according to competitive level (national or regional) / Perfil fisiológico de corredores de trilhas de longa distância adultos do sexo masculino: variações segundo o nível competitivo (nacional ou regional)

ABSTRACT Objective To describe and identify the importance of different indicators of the aerobic and anaerobic fitness of male ultra-trail runners according to their level of participation (regional or national). Methods Forty-four male ultra-trail runners were assessed (36.5±7.2 years). They were classified as regional (n=25) and national (n=19). Wingate test was used to assess the anaerobic pathway. A progressive incremental running test was performed and ventilatory thresholds registered, in parallel to heart rate and lactate concentration at the end of the protocol. Comparison between groups was performed using independent samples t-test. Results No significant differences were found between outputs derived from Wingate test. For aerobic fitness, while examining absolute values, differences were uniquely significant for the second ventilatory threshold (ultra-trail regional runners: 3.78±0.32L.min-1; ultra-trail national runners: 4.03±0.40L.min-1 p<0.05). Meantime, when aerobic fitness was expressed per unit of body mass, differences were significant for the second ventilatory threshold (ultra-trail regional runners: 50.75±6.23mL.kg-1.min-1; ultra-trail national runners: 57.88±4.64mL.kg-1.min-1 p<0.05) and also maximum volume of oxygen (ultra-trail regional runners: 57.33±7.66mL.kg-1.min-1; ultra-trail national runners: 63.39±4.26mL.kg-1.min-1 p<0.05). Conclusion This study emphasized the importance of expressing physiological variables derived from running protocols per unit of body mass. Also, the second ventilatory threshold appears to be the best and the only aerobic fitness variable to distinguish between trail runners according to competitive level. Maximal oxygen uptake seems of relative interest to distinguish between long distance runners according to competitive level.

RESUMO Objetivo Descrever e comparar indicadores de aptidão metabólica em corredores de trilhas de longa distância (ultra trail running) adultos do sexo masculino, de acordo com o nível de competição (regional ou nacional). Métodos Foram avaliados 44 corredores masculinos com média de idade de 36,5±7,2 anos classificados como de nível regional (n=25) ou nacional (n=19). Foi utilizado o teste de Wingate para avaliação da via anaeróbica, enquanto o teste incremental de corrida em esteira também foi realizado para determinar os limiares ventilatórios, o consumo máximo de oxigênio, a frequência cardíaca e a concentração de lactato ao final do protocolo. A comparação entre os grupos foi realizada por estatística teste t para amostras independentes. Resultados As variáveis obtidas do teste Wingate não diferiram de forma significativa entre os grupos. No que diz respeito à aptidão aeróbica, foram encontradas diferenças significativas entre variáveis expressas em valores absolutos no segundo limiar ventilatório (corredores de nível regional: 3,78±0,32L.min-1; corredores de nível nacional: 4,03±0,40L.min-1; p<0,05). Quando considerados os valores expressos por unidade de massa corporal, o segundo limiar ventilatório (corredores de nível regional: 50,75±6,23mL.kg-1.min-1; corredores de nível nacional: 57,88±4,64mL.kg-1.min-1; p<0,05) e o volume máximo de oxigênio (corredores de nível regional: 57,33±7,66mL.kg-1.min-1; corredores de nível nacional: 63,39±4,26mL.kg-1.min-1; p<0,05) também diferiram de forma significativa. Conclusão Este estudo destacou a importância de se expressarem variáveis fisiológicas derivadas de protocolos de corrida por unidade de massa corporal. Além disso, o segundo limiar ventilatório pareceu ser o melhor e único indicador de aptidão aeróbica para a diferenciação de corredores de trilha de longa distância, segundo o nível competitivo. O consumo máximo de oxigênio não é especialmente relevante para distinguir os corredores de trilha de longa distância, segundo o nível competitivo.

Body composition among long distance runners

SUMMARY OBJECTIVE The current study aimed to examine the body composition of adult male ultra-trail runners (UTR) according to their level of participation (regional UTR-R, vs. national UTR-N). METHODS The sample was composed of 44 adult male UTR (aged 36.5±7.2 years; UTR-R: n=25; UTR-N: n=19). Body composition was assessed by air displacement plethysmography, bioelectrical impedance, and dual-energy X-ray absorptiometry. In addition, the Food Frequency Questionnaire (FFQ) was applied. A comparison between the groups was performed using independent samples t-test. RESULTS Significant differences between groups contrasting in the competitive level were found for chronological age (in years; UTR-R: 38.8±8.2 vs. UTR-N: 33.5±4.1); body density (in L.kg-1; UTR-R: 1.062±0.015 vs. UTR-N: 1.074±0.009); and fat mass (in kg; UTR-R: 12.7±6.8 vs. UTR-N: 7.6±2.7). CONCLUSION UTR-N were younger, presented higher values for body density, and had less fat mass, although no significant differences were found for fat-free mass. The current study evidenced the profile of long-distance runners and the need for weight management programs to regulate body composition.

RESUMO OBJETIVO O presente estudo objetivou examinar a composição corporal dos corredores de ultra-trail (UTR) e, adicionalmente, comparar dois grupos de acordo com o nível de participação (Regional vs. Nacional, respectivamente UTR-R e UTR-N). MÉTODOS A amostra foi composta por 44 corredores adultos masculinos (36,5±7,2 anos de idade; UTR-R: n=25; UTR-N: n=19). A composição corporal foi avaliada recorrendo à pletismografia de ar deslocado, bioimpedância elétrica e absorciometria de raios X de dupla energia. Adicionalmente, foi utilizado o Questionário de Frequência Alimentar. A comparação entre grupos foi realizada com base na prova t-student para amostras independentes. RESULTADOS Foram encontradas diferenças significativas por nível de competição para as seguintes variáveis dependentes: idade cronológica (em anos; UTR-R: 38,8±8,2 vs. UTR-N: 33,5±4,1); densidade corporal (em kg/L; UTR-R: 1,062±0,015 L/kg vs. UTR-N: 1,074±0,009); massa gorda (em kg; UTR-R: 12,7±6,8 kg vs. UTR-N: 7,6±2,7). CONCLUSÃO Os UTR-N tendem a ser mais jovens e apresentam valores superiores de densidade corporal e, consequentemente, valores menores de massa gorda, sendo a massa isenta de gordura semelhante entre os grupos. O presente estudo determinou o perfil dos corredores adultos masculinos de longa distância (ultra-trail), realçando a importância de uma cuidadosa regulação da massa corporal.

Body composition, strength static and isokinetic, and bone health: comparative study between active adults and amateur soccer players / Composição corporal, força estática e isocinética, e saúde óssea: estudo comparativo entre adultos ativos e futebolistas amadores

ABSTRACT Objective: To compare tissue composition, total and regional bone mineral content and bone mineral density, static hand grip and knee joint isokinetic strength between amateur soccer players and Control Group. Methods: Cross-sectional study. Air displacement plethysmography was used to estimate body volume and, in turn, density. Body composition, bone mineral content and bone mineral density were assessed for the whole body and at standardized regions using dual energy X-ray absorptiometry. Static grip strength was assessed with an adjustable dynamometer, and peak torque derived from isokinetic strength dynamometer (concentric muscular knee actions at 60°/s). Magnitude of the differences between groups was examined using d-Cohen. Results: Compared to healthy active adults, soccer players showed larger values of whole body bone mineral content (+651g; d=1.60; p<0.01). In addition, differences between groups were large for whole body bone mineral density (d=1.20 to 1.90; p<0.01): lumbar spine, i.e. L1-L4 (+19.4%), upper limbs (+8.6%) and lower limbs (+16.8%). Soccer players attained larger mean values in strength test given by static hand grip protocol (+5.6kg, d=0.99; p<0.01). Conclusion: Soccer adequately regulates body composition and is associated better bone health parameters (bone mineral content and density at whole-body and at particular sites exposed to mechanical loadings).

RESUMO Objetivo: Comparar a composição de tecidos, o conteúdo mineral ósseo e a densidade mineral óssea totais e por regiões do corpo, a força de preensão manual estática, e força isocinética da articulação do joelho, entre um grupo de jogadores de futebol amadores e um Grupo Controle. Métodos: Estudo transversal utilizando pletismografia de ar deslocado para estimar o volume corporal, para subsequente cálculo da densidade corporal. A composição de tecidos, o conteúdo mineral ósseo e a densidade mineral óssea foram avaliados para o corpo todo e regiões padronizadas através da absorciometria de raios-X de dupla energia. A força de preensão manual estática foi avaliada por um dinamômetro ajustável. Os momentos máximos de força das ações musculares concêntricas para os extensores e flexores do joelho foram avaliados pela dinamometria isocinética (60°/s). Foi calculado o valor d-Cohen para apreciar a magnitude do efeito das diferenças entre grupos. Resultados: Os futebolistas apresentaram níveis superiores de conteúdo mineral ósseo em comparação com os adultos ativos do Grupo Controle (+651g; d=1,60; p<0,01) e obtiveram valores superiores de densidade mineral óssea (d: 1,20 a 1,90; p<0,01) para a coluna lombar, L1-L4 (+19,4%), membros superiores (+8,6%) e membros inferiores (+16,8%). Para a força de preensão (estática) a diferença foi moderada (d=0,99; p<0,01) com valores mais elevados apresentados pelo futebolistas (+5,6kg; d=0,99; p<0,01). Conclusão: A prática de futebol promove uma regulação adequada da composição corporal (tecidos magro e gordo) e ganhos na densidade mineral óssea, mais acentuada em partes do corpo com maior exposição aos impactos mecânicos da atividade motora.

Motor coordination as predictor of physical fitness in prepubertal boys / Coordenação motora como preditora da aptidão física de meninos pré-púberes

Abstract Motor competence is associated with numerous health-related variables of the pediatric population. The present study aimed to analyze the effect of the level of motor coordination on performance in several physical fitness tests in prepubertal boys, before and after controlling body mass. The sample consisted of 71 Brazilian eight-year-old boys. Anthropometry included stature, body mass and estimates of fat mass and fat-free mass. Biological maturation was evaluated by the percentage of predicted adult stature. The physical tests applied were 2-kg medicineball throw, handgrip strength, sit-ups in 60 seconds, standing long jump, 10x5-m shuttle run, 20-m shuttle run and sit and reach. Motor coordination was assessed by the Körperkoordinationtest für Kinder (KTK). For data analysis, descriptive statistics, Pearson correlation, Student's t-test and ANCOVA were used, with body mass as covariate. Significance level was set at p <0.05. There was no difference in maturational level between the different groups of coordinative performance. The results showed that boys with better performance in motor coordination tests are associated with better results in physical fitness tests, especially those involving body mass displacement. This trend remained even when comparing groups controlling body mass, except for the sit-up test. Therefore, it could be concluded that motor coordination is a predictor of physical fitness in prepubertal boys.

Resumo A competência motora está associada a inúmeras variáveis relacionadas à saúde da população pediátrica. O presente estudo teve como objetivo analisar o efeito do nível de coordenação motora no desempenho em diversos testes de aptidão física de meninos pré-púberes, antes e depois de controlar o efeito exercido pela massa corporal. A amostra foi composta por 71 meninos brasileiros com oito anos de idade. A antropometria considerou a estatura, a massa corporal e as estimativas de gordura corporal e de massa magra. A maturação biológica foi avaliada pelo percentual da estatura matura predita. Os testes físicos aplicados foram o lançamento de medicineball 2-kg, preensão manual, abdominais em 60 segundos, salto horizontal, 10x5-m shuttle run, 20-m shuttle run e sentar e alcançar. A coordenação motora foi avaliada pelo Körperkoordinationtest für Kinder (KTK). Para análise dos dados, foi feita a estatística descritiva, a correlação de Pearson, o teste t-Student e a ANCOVA, com a massa corporal como covariável. O nível de significância adotado foi de p<0,05. Não houve diferença quanto ao estado maturacional entre os diferentes grupos de desempenho coordenativo. Os resultados evidenciaram que meninos com melhor desempenho em teste de coordenação motora estão associados aos melhores resultados em testes de aptidão física, nomeadamente naqueles que envolvem deslocamento da massa corporal. Esta tendência permaneceu mesmo quando foi realizada comparação entre ambos os grupos com o controle da massa corporal, com exceção do teste de abdominais. Pode-se concluir que a coordenação motora é preditora da aptidão física em meninos pré-púberes.

Biocultural approach of the association between maturity and physical activity in youth / Abordagem biocultural da associação entre maturação e atividade física na juventude

Abstract Objective: To test the biocultural model through direct and indirect associations between biological maturation, adiposity, cardiorespiratory fitness, feelings of sadness, social relationships, and physical activity in adolescents. Methods: This was a cross-sectional study conducted with 1,152 Brazilian adolescents aged between 10 and 17 years. Somatic maturation was estimated through Mirwald's method (peak height velocity). Physical activity was assessed through Baecke questionnaire (occupational, leisure, and sport contexts). Body mass index, body fat (sum of skinfolds), cardiorespiratory fitness (20-m shuttle run test), self-perceptions of social relationship, and frequency of sadness feelings were obtained for statistical modeling. Results: Somatic maturation is directly related to sport practice and leisure time physical activity only among girls (β = 0.12, p < 0.05 and β = 0.09, respectively, p < 0.05). Moreover, biological (adiposity and cardiorespiratory fitness), psychological (sadness), and social (satisfaction with social relationships) variables mediated the association between maturity and physical activity in boys and for occupational physical activity in girls. In general, models presented good fit coefficients. Conclusion: Biocultural model presents good fit and emotional/biological factors mediate part of the relationship between somatic maturation and physical activity.

Resumo Objetivo: Testar o modelo biocultural por meio de associações diretas e indiretas entre maturação biológica, adiposidade, capacidade cardiorrespiratória, sentimentos de tristeza, relacionamentos sociais e atividade física em adolescentes. Métodos: Este foi um estudo transversal feito com 1.152 adolescentes brasileiros entre 10 e 17 anos. A maturação somática foi estimada por meio do método de Mirwald (pico da velocidade de crescimento). A atividade física foi avaliada por meio do questionário de Baecke (contextos ocupacional, lazer e prática de esportes). Foram obtidos o índice de massa corporal, gordura corporal (soma de dobras cutâneas), capacidade cardiorrespiratória (teste shuttle run de 20 metros), autopercepções de relação social e frequência de sensação de tristeza para modelagem estatística. Resultados: A maturação somática mostrou-se diretamente relacionada à prática de esportes e à atividade física de lazer somente entre meninas (β = 0,12, p < 0,05 e β = 0,09, respectivamente, p < 0,05). Ademais, as variáveis biológicas (adiposidade e aptidão cardiorrespiratória), psicológica (tristeza) e social (satisfação com os relacionamentos sociais) mediaram a associação entre maturação e atividade física em meninos e para atividade física ocupacional em meninas. Em geral, os modelos apresentaram bons coeficientes de ajuste. Conclusão: O modelo biocultural apresenta bom ajuste e fatores emocionais/biológicos mediam parte da relação entre maturação somática e atividade física.

Agreement between dual x-ray absorptiometers using pencil beam and fan beam: indicators of bone health and whole-body plus appendicular tissue composition in adult athletes

SUMMARY OBJECTIVE: The current study was aimed to examine intra-individual variation on indicators of bone health in addition to whole-body plus appendicular tissue measurements using two concurrent assessments based on pencil beam and fan beam dual energy X-ray absorptiometry (DXA) systems in adult athletes from several sports. METHOD: Thirty-two male participants (27.6±10.1 years) were measured on anthropometry including multifrequency bioelectric impedance and air-displacement plethysmography. Bone mineral content (BMC), bone area, fat and lean soft tissue were derived using pencil beam (Lunar DPX-MD+) and fan beam (Lunar iDXA) absorptiometry. Bone mineral density (BMD) was obtained for the femoral neck, trochanter and triangle of ward. Finally, the right thigh was defined as a region of interest (ROI). Analyses comprised intra-class correlation (ICC), Effect size (d) from mean differences of repeated measurements, coefficient of variation (CV) RESULTS: ICC were >0.900 for all measurements. Intra-individual differences were large for BMC (d=1,312; CV=2,7%), bone area (d=1,761; CV=2,7%), fat tissue (d=1,612; CV=11%) and all indicators of appendicular lean soft tissue (d=1,237-1687; CV=2,0-4,1%). A very large difference (d=4,014; CV=8.4%) was diagnosed for lean soft tissue of the ROI. CONCLUSION: Although differences among concurrent instruments for BMC and bone area, the effect size of mean differences was negligible for BMD. Fat and lean soft tissue derived from DXA should be interpreted as reference values (not criterion) due to equipment-related variation, more apparently in the ROI values.

RESUMO OBJETIVO: O presente estudo examinou a concordância entre os indicadores de saúde óssea e composição tecidual resultantes da aplicação de equipamentos concorrentes de absorciometria de raios X de dupla energia (DXA). MÉTODO: A amostra (n = 32), com 27,6 ± 10,1 anos de idade avaliados antropometricamente, inclui impedância bioelétrica com multifrequência e pletismografia de ar deslocado. O conteúdo mineral ósseo (CMO), a área de tecido ósseo, o tecido magro e o tecido gordo de corpo inteiro foram obtidos considerando o modo pencil beam (Lunar DPX-MD+) e o fan beam (Lunar iDXA). Para cada um dos equipamentos, foi efetuado um scanner proximal do fêmur, sendo produzida informação sobre a densidade mineral óssea (DMO) do colo, nomeadamente triângulo de Ward, trocanter e haste. Na fase de processamento, foi definida uma região de interesse (ROI; coxa direita). As análises compreenderam a diferença de médias de medidas repetidas com cálculo da magnitude de efeitos (d), coeficiente de correlação intraclasse (CCI), coeficiente de variação (CV). RESULTADOS: Foram obtidos CCI>0,900 para todas as medidas, com diferenças intraindividuais largas apenas para CMO (d = 1,312; CV = 2,7%), área de tecido ósseo (d = 1,761; CV = 2,7%), tecido gordo total (d = 1,612; CV = 11%) e tecido magro em todos os segmentos (d = 1,237-1,687; CV = 2,0-41%). A massa magra da ROI apresentou uma variaçāo intraindividual muito larga (d = 4,014; CV = 8,4%). CONCLUSÃO: Foram encontradas diferenças negligenciáveis para a DMO de corpo todo. As medidas de massa gorda e massa magra obtidas por DXA nāo devem ser tidas como critério, mas antes como referenda, muito especialmente quando se delimita uma ROI.

Quality of life, school backpack weight, and nonspecific low back pain in children and adolescents / Qualidade de vida, peso das mochilas escolares e lombalgia não específica em crianças e adolescentes

OBJECTIVES: To describe the degree of disability, anthropometric variables, quality of life (QoL), and school backpack weight in boys and girls aged 11-17 years. The differences in QoL between those who did or did not report low back pain (LBP) were also analyzed. METHODS: Eighty-six girls (13.9 ± 1.9 years of age) and 63 boys (13.7 ± 1.7 years of age) participated. LBP was assessed by questionnaire, and disability using the Roland-Morris Disability Questionnaire. QoL was assessed by the Pediatric Quality of Life Inventory (PedsQL). Multivariate analyses of variance and covariance were used to assess differences between groups. RESULTS: Girls reported higher disability than boys (p = 0.01), and lower QoL in the domains of physical (p < 0.001) and emotional functioning (p < 0.01), psychosocial health (p = 0.02) and physical health summary score (p < 0.001), and on the total PedsQL score (p < 0.01). School backpack weight was similar in both genders (p = 0.61) and in participants with and without LBP (p = 0.15). After adjustments, participants with LBP reported lower physical functioning (p < 0.01), influencing lower physical health summary score (p < 0.01). CONCLUSIONS: Girls had higher disability and lower QoL than boys in the domains of physical and emotional functioning, psychosocial health, and physical health summary scores, and on the total PedsQL score; however, similar school backpack weight was reported. Participants with LBP revealed lower physical functioning and physical health summary score, yet had similar school backpack weight to those without LBP. .

OBJETIVOS: Descrever o grau de incapacidade, as variáveis antropométricas, a qualidade de vida (QV) e o peso das mochilas escolares em meninos e meninas com 11-17 anos. Também são analisadas as diferenças na QV entre os que relataram ou não lombalgia (LBP). MÉTODOS: 86 meninas (13,9 ± 1,9 anos) e 63 meninos (13,7 ± 1,7 anos) participaram. A LBP foi avaliada por um questionário e a incapacidade pelo Questionário Roland-Morris. A QV foi avaliada pelo Questionário Pediátrico sobre Qualidade de Vida (PedsQL). As análises de variância e de covariância multivariadas foram usadas para avaliar as diferenças entre os grupos. RESULTADOS: As meninas relataram maior incapacidade do que os meninos (p = 0,01) e menor QV nos domínios de funcionamento físico (p < 0,001) e emocional (p < 0,01), no escore sumário de saúde psicossocial (p = 0,02) e saúde física (p < 0,001) e no escore total no PedsQL (p < 0,01). O peso das mochilas escolares era semelhante para ambos os sexos (p = 0,61) e para os participantes com e sem LBP (p = 0,15). Após ajustes, os participantes com LBP relataram menor funcionamento físico (p < 0,01), o que influenciou um menor escore sumário de saúde física (p < 0,01). CONCLUSÕES: As meninas tiveram maior incapacidade e menor QV do que os meninos nos domínios de funcionamento físico e emocional, nos escores sumários de saúde psicossocial e física e no escore total no PedsQL; contudo, foi relatado um peso semelhante das mochilas escolares. Os participantes com LBP revelaram menor funcionamento físico e escore sumário de saúde física, mesmo carregando mochilas escolares de mesmo peso do que aqueles sem LBP. .

Endothelial wall thickness, cardiorespiratory fitness and inflammatory markers in obese and non-obese adolescents

Background: Increased carotid intima-media thickness (c-IMT) is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated. Objective : To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents. Method : Thirty-five obese subjects (19 boys) and 18 non-obese subjects (9 boys), aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max), and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, C-reactive protein (CRP), and adiponectin were assessed. c-IMT was measured by ultrasound. Results: The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c), adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max. Conclusions : Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents. .