Associations Between Substitution of Sedentary Behavior Patterns With Physical Activity and Cardiovascular Risk Factors in Adolescents: A 3-Year Longitudinal Study.

BACKGROUND: Little is known on how the substitution of time spent in sedentary behavior (SB) patterns with time spent in physical activity impacts cardiovascular risk factors during adolescence. The study aimed to investigate how the substitution of time spent in SB and sedentary bouts with time spent in different physical activity intensities was associated with longitudinal changes in cardiovascular risk factors in analyses stratified by sex. METHODS: This is a prospective cohort study with a mean follow-up period of 3.2 (±0.34) years, involving 109 (60 girls and 49 boys) Brazilian adolescents. Body mass index, waist circumference, and cardiorespiratory fitness were the cardiovascular risk factors considered. A cardiovascular risk score was calculated. Sedentary bouts, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) were measured by accelerometers. Multivariate linear regression models adopting the isotemporal substitution were used to analyze the association between substitution of 10 minutes per day of sedentary bouts with LPA and MVPA and risk factors. All analyses considered 5% significance levels. RESULTS: Substitutions of SB, short and long bouts, with MVPA were associated with higher cardiorespiratory fitness in boys (ß = 0.077; 95% confidence interval, 0.001 to 0.55; ß = 0.076; 95% confidence interval, 0.003 to 0.154; and ß = 0.084; 95% confidence interval, 0.001 to 0.167, respectively). No associations were observed when analyses involved substitution of sedentary bouts with LPA, adiposity, cardiovascular risk score, and girls. CONCLUSIONS: Substituting SB bouts with MVPA appears to favorably influence changes of cardiorespiratory fitness in boys during adolescence. Greater benefits appear to occur when longer sedentary bouts are substituted by MVPA.

Burden of metabolic syndrome on primary healthcare costs among older adults: A cross-sectional study.

BACKGROUND: The impact of metabolic syndrome (MetS) on healthcare costs remains unclear in the literature. OBJECTIVES: To determine the impact of MetS on primary healthcare costs of adults, as well as to identify the impact of physical activity and other covariates on this phenomenon. DESIGN AND SETTING: This cross-sectional study was conducted in the city of Presidente Prudente, State of São Paulo/Brazil, in 2016. METHODS: The sample comprised 159 older adults (> 50 years) of both sexes (110 women) who were identified from their medical records in the Brazilian National Health Service. Healthcare costs (US$) were assessed through medical records and divided into medical consultations, medications, laboratory tests, and total costs. MetS was assessed using medical records. RESULTS: The Brazilian National Health Service spent more on consultations (US$ 22.75 versus US$ 19.39; + 17.3%) and medication (US$ 19.65 versus US$ 8.32; + 136.1%) among adults with MetS than among those without MetS, but the costs for laboratory tests were similar (P = 0.343). Total costs were 53.9% higher in adults with MetS than in those without the diagnosis of the disease (P = 0.001). Regarding total costs, there was an increase of US$ 38.97 when five components of MetS were present (P = 0.015), representing an increase of approximately 700%, even after adjusting for sex, age, and physical activity. CONCLUSION: In conclusion, the presence of the MetS is responsible for increasing primary care costs among older adults, especially in those related to medicines.

Sports participation in childhood and adolescence and physical activity intensity in adulthood.

OBJECTIVES: The aim of the present study was to analyze the association between sports participation in childhood and adolescence and the practice of physical activity at different intensities in adulthood, and to verify if some sports participation characteristics such as number of sports; type of sport (individual, collective or a combination of both) and total estimated sports participation time are associated with the different physical activity intensities in adulthood. DESIGN: This is a cross-sectional study. METHODS: This study included 129 young adults of both sexes aged 18-25 years. Sports participation in childhood (7-10 years) and adolescence (11-17 years) was retrospectively estimated through specific questionnaire. Light, moderate, vigorous and moderate to vigorous intensity physical activity was objectively estimated by accelerometers. To verify the association between SP in childhood and adolescence and BP intensities in adults, multiple linear regression was adopted, with 5% significance. RESULTS: Analyses showed that, in females, sports participation in childhood (ß = 0.315; R2 = 0.14; P = 0.020) and persistence in sports participation (ß = 0.364; R2 = 0.18; P = 0.007) were positive predictors of vigorous physical activity in adulthood. In addition, the comparison according to the specificities of the sport practice, indicated that participation in two or more sports in childhood, one sport and collective sports in adolescence and at least one year of sports participation throughout childhood and adolescence were associated with longer time in vigorous physical activity intensity and MVPA (minutes/day) in adult females (P < 0.05). CONCLUSIONS: It could be concluded that sports participation indicators in childhood and adolescence were considered predictors of vigorous physical activity in adult females. In addition, number of sports, type of sport and practice time in childhood and adolescence seem to predict vigorous and moderate to vigorous levels of physical activity for adult females.

Association between childhood anthropometric indicators and bone mineral density in adulthood / Associação entre indicadores antropométricos na infância e densidade mineral óssea na idade adulta

ABSTRACT Objective: This study aimed to verify the association between childhood anthropometric indicators and areal bone mineral density (aBMD) in adulthood. Methods: Repeated measures of 137 subjects (68 females) were obtained in childhood (9.2±1.5 years of age) and adulthood (22.3±1.7 years of age). aBMD (g/cm2) was assessed for whole body, lumbar spine, upper and lower limbs, and femoral neck in adulthood using dual-energy X-ray absorptiometry. Anthropometric measurements of body weight (BW), height, triceps and subscapular skinfolds were obtained in childhood. The anthropometric indicators used were BW, body mass index (BMI), and sum of skinfolds (ΣSF). Simple linear regression was used to assess the association between childhood anthropometric indicators and aBMD in adulthood, controlled by chronological age and stratified by sex, with 5% statistical significance. Results: In females, multiple associations were observed between anthropometric indicators and aBMD, with higher coefficients for BMI (β=0.020; R2=0.20; p<0.01 for right femoral neck to β=0.008; R2=0.16; p<0.01 for upper limbs), followed by BW (β=0.003; R2=0.21; p<0.01 for upper limbs to β=0.008; R2=0.20; p<0.01 for right femoral neck) and ΣSF (β=0.001; R2=0.06; p<0.01 for upper limbs to β=0.005; R2=0.12; p<0.01 for right femoral neck). In males, associations were observed only for the lumbar spine region (β=0.016; R2=0.09 for BMI to β=0.004; R2=0.06; p<0.01 for ΣSF). Conclusions: Anthropometric indicators of childhood proved to be sensitive predictors of aBMD in adulthood, especially in females. BMI indicated a greater association with aBMD in both sexes.

RESUMO Objetivo: O objetivo do estudo foi verificar a associação entre os indicadores antropométricos da infância com a área da densidade mineral óssea (aDMO) na idade adulta. Métodos: Medidas repetidas de 137 sujeitos (68 do sexo feminino) foram obtidos na infância (9,2±1,5 anos de idade) e idade adulta (22,3±1,7 anos de idade). A aDMO (g/cm2) foi avaliada para todo o corpo, coluna lombar, membros superiores e inferiores e colo do fêmur na idade adulta usando a absorciometria radiológica de dupla energia (DXA). Medidas antropométricas de peso corporal, estatura e dobras cutâneas das regiões tricipital e subescapular foram obtidas na infância. Os indicadores antropométricos utilizados para as análises foram o peso corporal (PC), o índice de massa corporal (IMC) e o somatório de dobras cutâneas (ΣDC). Regressão linear simples controlada pela idade e estratificada por sexo foi empregada para avaliar a associação entre os indicadores antropométricos do período da infância na aDMO na idade adulta, com significância estatística de 5%. Resultados: No sexo feminino, múltiplas associações foram observadas entre os indicadores antropométricos e a aDMO, com maiores coeficientes para IMC (β=0,020; R2=0,20; p<0.01 para colo do fêmur direito a β=0,008; R2=0,16; p<0,01 para membros superiores), seguido da PC (β=0,003; r2=0,21; p<0,01 para membros superiores a β=0,008; r2=0,20; p<0,01 para colo do fêmur direito) e ΣDC (β=0,001; R2=0,06; p<0,01 para membros superiores a β=0,005; R2=0,12; p<0,01 para colo do fêmur direito). No sexo masculino, associações ocorreram apenas na região da coluna (β=0,016; R2=0,09 para IMC a β=0,004; R2=0,06; p<0,01 para ΣDC). Conclusões: Indicadores antropométricos da infância mostraram ser sensíveis preditores da aDMO na idade adulta, especialmente no sexo feminino. O IMC indicou maior associação com a aDMO em ambos os sexos.

Burden of metabolic syndrome on primary healthcare costs among older adults: A cross-sectional study

ABSTRACT BACKGROUND: The impact of metabolic syndrome (MetS) on healthcare costs remains unclear in the literature. OBJECTIVES: To determine the impact of MetS on primary healthcare costs of adults, as well as to identify the impact of physical activity and other covariates on this phenomenon. DESIGN AND SETTING: This cross-sectional study was conducted in the city of Presidente Prudente, State of São Paulo/Brazil, in 2016. METHODS: The sample comprised 159 older adults (> 50 years) of both sexes (110 women) who were identified from their medical records in the Brazilian National Health Service. Healthcare costs (US$) were assessed through medical records and divided into medical consultations, medications, laboratory tests, and total costs. MetS was assessed using medical records. RESULTS: The Brazilian National Health Service spent more on consultations (US$ 22.75 versus US$ 19.39; + 17.3%) and medication (US$ 19.65 versus US$ 8.32; + 136.1%) among adults with MetS than among those without MetS, but the costs for laboratory tests were similar (P = 0.343). Total costs were 53.9% higher in adults with MetS than in those without the diagnosis of the disease (P = 0.001). Regarding total costs, there was an increase of US$ 38.97 when five components of MetS were present (P = 0.015), representing an increase of approximately 700%, even after adjusting for sex, age, and physical activity. CONCLUSION: In conclusion, the presence of the MetS is responsible for increasing primary care costs among older adults, especially in those related to medicines.

Time Reallocations From Sedentary Behavior to Physical Activity and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review.

BACKGROUND: Recent statistical approaches have allowed consideration of the integrated relationships between sedentary behavior (SB) and physical activity (PA) with different health outcomes. The present paper aimed to systematically review the literature and synthesize evidence about associations between hypothetical reallocations from SB to different PA intensities and cardiovascular risk factors in youth. METHODS: A systematic search of 8 databases was performed. Observational studies with a population of children and/or adolescents and based on statistical analysis that investigated the associations between time reallocations from SB to PA and cardiovascular risk factors were included. RESULTS: Twenty-eight studies met the inclusion criteria. Level of evidence (derived from cross-sectional studies) indicated that the reallocation from SB to moderate to vigorous PA was beneficially associated with adiposity, cardiorespiratory fitness, and cardiometabolic biomarkers in youth. Reallocation from SB to light PA was not associated with the analyzed outcomes. Associations derived from longitudinal studies were mostly inconclusive. CONCLUSION: Cardiovascular risk factors could be improved by increasing moderate to vigorous PA at the expense of time spent in SB in pediatric populations. Prospective studies or studies investigating the effects of reallocating sedentary bouts to PA are needed.

Comparison Between Cardiorespiratory Fitness and Functions of Cognitive Control in Adolescents: A Tracking Study of 3 Years.

PURPOSE: Compare tracking groups with cognitive control functions and plasma brain-derived neurotrophic factors concentrations from childhood to adolescence. METHODS: This is a prospective study with 3 years of follow-up. At baseline, data from 394 individuals were collected (11.7 y), and data were obtained from 134 adolescents (14.9 y) at the 3-year follow-up. At both time points, anthropometric and maximal oxygen uptake data were collected. Cardiorespiratory fitness (CRF) groups were classified into high or low CRF. At follow-up, cognitive outcomes were collected via the Stroop and Corsi block test; plasma brain-derived neurotrophic factors concentrations were also analyzed. RESULTS: Comparisons demonstrated that maintaining high CRF over 3 years results in shorter reaction time, better inhibitory control, and higher working memory values. Likewise, the group that moved from low to high CRF over 3 years presented better reaction time. Plasma brain-derived neurotrophic factors concentrations were higher for the group that increased its CRF over the 3 years in relation to the low-low group (90.58 pg·mL-1; P = .004). However, after scaling by an allometric approach, differences were only found for reaction time and working memory between high-high and high-low groups. CONCLUSION: Maintaining high CRF over 3 years was positively related to reaction time and working memory in relation to adolescents that decreased their levels of CRF.

Association between cardiorrespiratory fitness and cognitive control: is somatic maturity an important mediator?

BACKGROUND: Recently some articles presented information related to the possible effect of maturity over the cognitive control and cardiorespiratory fitness, however little is known about the real effects of maturity in the relation of these variables. In this sense, the purpose of this study was to examine the potential mediating role of somatic maturity on the association between cardiorespiratory fitness (CRF) and cognitive control. METHODS: This three-year longitudinal research comprises two data collection groups: a baseline conducted in 2016 with 394 adolescents (aged 11.7 ± 0.6 years) and a follow-up in 2019 with 134 adolescents (aged 14.9 ± 0.7 years). Anthropometry data, 20-m shuttle run test and peak height velocity (PHV) to determine the maximum oxygen uptake (VO2max) and somatic maturity, respectively, were collected at both sampling times. In parallel, the Sociodemographic and cognitive control function variables were included in the follow-up to evaluate the inhibitory control (by the Stroop test) and the visuo-spatial working memory (by the Corsi block-tapping test). Associations between CRF and cognitive functions were computed by multiple linear regression, with mediation as a function of PHV. RESULTS: CRF exhibited transversal associations with reaction time in congruent (ß = -0.004; p = 0.001) and incongruent (ß = -0.005; p = 0.004) stimulus-responses. Meanwhile, the variation in VO2max over the three year-study had a significant impact on the reaction time of congruent (ß = -0.006; p = 0.001) and incongruent (ß = -0.006; p = 0.012) responses at follow-up. However, PHV did not show a significant association with the cognitive functions, indicating no mediating role. CONCLUSIONS: Although the associations between CRF and the cognitive functions exhibited great transversal and longitudinal impacts, somatic maturity did not affect the cognitive control functions, associating exclusively with CRF.

Association between patterns of sedentary time and academic performance in adolescents: the mediating role of self-concept.

OBJECTIVE: To analyze the association between the pattern of sedentary time (bouts and breaks) with academic performance, with an emphasis on the mediating role of self-concept. METHODS: Participants in the cross-sectional study were 394 adolescents (208 girls), aged 10-14 years, from sixth grade from Londrina, Paraná, Brazil. The sedentary time pattern was measured through accelerometry. Definitions: sedentary bouts - uninterrupted periods of sedentary behavior; breaks - non-sedentary period between two sedentary bouts. The self-concept was estimated using the Piers-Harris II Inventory. Academic performance was obtained by school grades. RESULTS: Short sedentary bouts were associated with higher academic performance in boys (1-4 minutes: ß=0.035, p=0.007) and girls (1-4 minutes: ß=0.031, p=0.014; 5-14 minutes: ß=0.054, p=0.001). Long bouts (30 minutes) were associated with lower academic performance in boys (ß=-0.023; p=0.011) and girls (ß=-0.032; p<0.001). For girls, total and intellectual self-concept mediated the association between all sedentary pattern and academic performance (bouts 1-4 minutes [total: 39% and intellectual: 42.8%]; bouts 5-14 minutes [total: 21.5% and intellectual: 35.4%]; bouts ≥30 minutes [total: 22.6% and intellectual: 32.3%]; and breaks [total: 38.9% and intellectual: 40.7%]). For boys, the total (56.4%) and intellectual (82.9%) self-concept mediated only the association between bouts of 5-14 minute and academic performance. CONCLUSIONS: The pattern of sedentary time is associated with academic performance in adolescents and this association is mediated by self-concept, especially in girls.

Mensuração da atividade física e comportamento sedentário: uma análise baseada em grupos de pesquisa / Measurement of physical activity and sedentary behavior: a research group-based analysis

O presente estudo caracterizou os grupos de pesquisa brasileiros que possuem linhas de pesquisa voltadas à temática da mensuração da atividade física e/ou comportamento sedentário. Autores de artigos originais envolvendo desenvolvimento, adaptação, tradução e testagem de qualidade de medidas de instrumentos da atividade física/comportamento sedentário na população brasileira foram convidados a responder um instrumento online contendo 19 questões para a identificação de líderes e de características gerais dos grupos de pesquisa. Vinte e oito grupos de pesquisa foram identificados, sendo o pioneiro criado na década de 1970 e a maioria nas últimas duas décadas. Enquanto a região sudeste apresentou a maior concentração de grupos, foi identificada ausência de grupos nas regiões norte e centro-oeste. Os métodos de mensuração mais testados por estes grupos foram os subjetivos, predominantemente questionários (n = 24), seguidos pelos métodos objetivos por meio de acelerômetros (n = 18) e pedômetros (n = 9). Foram identificadas várias conexões (parcerias permanentes com outros grupos/instituições) em nível nacional e internacional, especialmente com países da América do Norte, Europa e Austrália. Espera-se que os resultados do presente estudo possam estimular ações colaborativas entre grupos e pesquisadores brasileiros com o intuito de reduzir desigualdades regionais e aprimorar a produção do conhecimento na área da mensuração da atividade física e do comportamento sedentário

The present study characterized the Brazilian research groups that have research lines focused on the meas-uring of physical activity and/or sedentary behavior. Authors of original articles that involved the devel-opment, adaptation, translation, and quality testing of measures of physical activity/sedentary behavior instruments in the Brazilian population were invited to answer an online instrument containing 19 questions to identify leaders and general characteristics of research groups. Twenty-eight research groups were identified, the pioneer being created in the 1970's and the majority in the last two decades. While the Southeast region had the highest concentration of groups, the absence of groups was identified in the North and Midwest regions. The measurement methods most tested by these groups were subjective, predominantly questionnaires (n = 24), followed by objective methods using accelerometers (n = 18) and pedometers (n = 9). Several connections (permanent partnerships with other groups/institutions) were identified at national and international levels, especially with countries in North America, Europe, and Australia. It is expected that the results of the present study can stimulate collaborative actions between Brazilian groups and re-searchers to reduce regional inequalities and improve the production of knowledge in the area of measuring physical activity and sedentary behavior

Grupo de Trabalho em Mensuração da Atividade Física e Comportamento Sedentário: uma breve Apresentação / Work Group on Measurement of Physical Activity and Sedentary Behavior: a Brief Presentation

A Sociedade Brasileira de Atividade Física & Saúde (SBAFS) exerce importante papel na união dos pesquisadores e fortalecimento da área no Brasil. Por essa razão, as decisões e direcionamentos das diferentes gestões da SBAFS, auxiliam, no desenvolvimento e consolidação da área. Uma das importantes ações da SBAFS nos últimos anos foi a criação de Grupos de Trabalhos (GTs) sobre diferentes temáticas da atividade física e saúde. Um dos GTs criados foi o GT de Mensuração da Atividade Física e Comportamento Sedentário. Neste contexto, o presente manuscrito descreve a criação do referido GT, suas atividades e ações no período de 2019 e 2021

The Brazilian Society of Physical Activity & Health (SBAFS) plays an important role in uniting researchers and strengthening the field in Brazil. For this reason, the decisions and directions of the different leader-ships of SBAFS help in the development and consolidation of the area. One of the important actions of the SBAFS in recent years was the creation of Working Groups ( WGs) on different themes of physical activity and health. One of the WGs created was the Physical Activity and Sedentary Behavior Measurement WG. In this context, the aim of this manuscript is to describe the creation of the aforementioned WG, its activities and actions in the period of 2019 to 2021

Association between patterns of sedentary time and academic performance in adolescents: the mediating role of self-concept / Associação entre o padrão do tempo sedentário e o desempenho acadêmico em adolescentes: o papel mediador do autoconceito

Abstract Objective: To analyze the association between the pattern of sedentary time (bouts and breaks) with academic performance, with an emphasis on the mediating role of self-concept. Methods: Participants in the cross-sectional study were 394 adolescents (208 girls), aged 10-14 years, from sixth grade from Londrina, Paraná, Brazil. The sedentary time pattern was measured through accelerometry. Definitions: sedentary bouts — uninterrupted periods of sedentary behavior; breaks — non-sedentary period between two sedentary bouts. The self-concept was estimated using the Piers-Harris II Inventory. Academic performance was obtained by school grades. Results: Short sedentary bouts were associated with higher academic performance in boys (1-4 minutes: β=0.035, p=0.007) and girls (1-4 minutes: β=0.031, p=0.014; 5-14 minutes: β=0.054, p=0.001). Long bouts (30 minutes) were associated with lower academic performance in boys (β=-0.023; p=0.011) and girls (β=-0.032; p<0.001). For girls, total and intellectual self-concept mediated the association between all sedentary pattern and academic performance (bouts 1-4 minutes [total: 39% and intellectual: 42.8%]; bouts 5-14 minutes [total: 21.5% and intellectual: 35.4%]; bouts ≥30 minutes [total: 22.6% and intellectual: 32.3%]; and breaks [total: 38.9% and intellectual: 40.7%]). For boys, the total (56.4%) and intellectual (82.9%) self-concept mediated only the association between bouts of 5-14 minute and academic performance. Conclusions: The pattern of sedentary time is associated with academic performance in adolescents and this association is mediated by self-concept, especially in girls.

Resumo Objetivo: Analisar a associação entre o padrão do tempo sedentário (bouts e breaks) e o desempenho acadêmico, com ênfase no papel mediador do autoconceito. Métodos: Participaram deste estudo transversal 394 adolescentes (208 moças), de 10 a 14 anos, da sexta série de Londrina, Paraná, Brasil. O padrão do tempo sedentário foi obtido por meio de acelerometria. Definições: bouts sedentários — períodos ininterruptos em comportamento sedentário; breaks — período não sedentário entre duas séries sedentárias. O autoconceito foi estimado usando o Inventário Piers-Harris II. O desempenho acadêmico foi obtido pelas notas escolares. Resultados: Bouts sedentários curtos foram associados com maior desempenho acadêmico em rapazes (1-4 minutos: β=0,035, p=0,007) e moças (1-4 minutos: β=0,031, p=0,014; 5-14 minutos: β=0,054, p=0,001). Bouts longos (30 minutos) foram associados a menor desempenho acadêmico em rapazes (β=-0,023; p=0,011) e moças (β=-0,032; p<0,001). Para as moças, o autoconceito total e intelectual mediou a associação entre todos os padrões sedentários e o desempenho acadêmico (bouts de 1-4 minutos [total: 39% e intelectual: 42,8%]; bouts de 5-14 minutos [total: 21,5% e intelectual: 35,4%]; bouts ≥30 minutos [total: 22,6% e intelectual: 32,3%]; e breaks [total: 38,9% e intelectual: 40,7%]). Para os rapazes, o autoconceito total (56,4%) e intelectual (82,9%) mediaram apenas a associação entre bouts de 5-14 minutos e desempenho acadêmico. Conclusões: O padrão do tempo sedentário está associado ao desempenho acadêmico em adolescentes, e essa associação é mediada pelo autoconceito, principalmente em moças.

Comparison between ActiGraph GT3X and ActivPAL to assess sedentary behavior during the school period

Abstract Aims: This study aimed to compare the sedentary time measured using the ActiGraph GT3X accelerometer with the measurement of sitting and standing time obtained by ActivPAL inclinometers. Methods: This was a cross-sectional study conducted with a sample of 60 schoolchildren (34 males) of one elementary public school in Brazil. The students used both an ActiGraph GT3X accelerometer and an ActivPAL inclinometer, concurrently, positioned at the beginning and removed at the end of the school shift, for four days. For analysis, paired Student's t-tests, Pearson's correlation coefficients, intraclass correlation coefficients, and Bland-Altman plots were used. Results: When comparing sedentary time with sitting time, although correlated (r = 0.53; p < 0.001), the mean minutes were different (134.2 min/day in ActiGraph GT3X vs 120.3 min/day in ActivPAL; p < 0.001), with a bias of 13.9 min/day. When comparing the measurement of sedentary time with the sum of the sitting time plus standing time, different mean minutes were also observed (134.2 min/day in ActiGraph GT3X vs 177.0 min/day in ActivPAL; p < 0.001), and although the correlation was stronger (r = 0.75; p < 0.001), the bias was higher (−42.8 min/day). Conclusion: Sedentary time derived from the ActiGraph GT3X device should be used with caution to evaluate sedentary behavior in a school setting and may be interpreted only as non-moving activities (stationary behavior).

Development of cardiorespiratory fitness standards for working memory using receiver operating curves in 15-year-old adolescents.

BACKGROUND: Working memory performance is associated with better academic achievements in children and adolescents, and it is positively related to CRF. However, what level of cardiorespiratory fitness (CRF) discriminates higher working memory performance is not known. The purpose of this study was to identify CRF thresholds linked to working memory in adolescents. METHODS: Data of 141 adolescents (53.2 % girls) were collected (14.9 years) from a cross-sectional study during the year 2019. CRF was assessed by the 20-m shuttle run test, and maximal oxygen uptake was calculated using the Mahar´s equation. Working memory was evaluated by the Corsi blocks test and performance was classified by percentiles. Receiver operating characteristic (ROC) curve analysis was used to identify CRF thresholds. RESULTS: The ROC analysis indicated that CRF could be used to discriminate working memory in adolescents. CRF thresholds of ≥45.03 ml.kg- 1.min- 1for boys and ≥36.63 ml.kg- 1.min- 1for girls were found to be indicative of "normal" working memory performance. CONCLUSIONS: CRF could discriminate low and normal working memory performance in 14-16- year-old adolescents. These thresholds could allow for earlier identification and intervention of low working memory performance using CRF.

Association between tracking of extracurricular sports practice and weight status during childhood: a prospective cohort study.

BACKGROUND: Overweight and obesity have reached epidemic prevalences. Obesity control involves many factors and needs to begin early in childhood. OBJECTIVES: To ascertain the association between tracked extracurricular sports practice and weight status; and to analyze tracking of overweight and obesity among school-aged children. DESIGN AND SETTING: Prospective cohort study conducted in 13 public schools in Cianorte, Paraná, in 2012-2016. METHODS: The sample comprised 2459 schoolchildren in Cianorte, of mean age 6.3 years at baseline and 9.4 years at follow-up. Body mass index was calculated from body mass and height measurements. The children were grouped as normal weight, overweight or obese. Information on extracurricular sports practice was collected through the dichotomous question "Do you participate in any extracurricular sports?" ("yes" or "no"). RESULTS: Tracking of weight status showed that 75.5% maintained this, with kappa of 0.530. Tracking of extracurricular sports practice showed that 80.9% maintained this, with low concordance (kappa of 0.054). Weight status correlation between baseline and follow-up showed that overweight or obese individuals were 4.65 times (CI: 4.05-5.34) more likely to maintain the same classification or move from overweight to obese at follow-up. Correlation of extracurricular sports practice with overweight or obesity at follow-up was not significant. CONCLUSIONS: These results demonstrated that overweight or obese children were at higher risk of gaining weight than were normal-weight children. In addition, the proportion of these children who maintained extracurricular sports practices over the years was low. Maintenance of this variable was not associated with weight status.

Association Between Device-Measured Moderate-to-Vigorous Physical Activity and Academic Performance in Adolescents.

BACKGROUND: Although many studies found a positive association between physical activity (PA) and academic performance (AP), most did not consider important variables of school setting and students' self-concept. AIMS: To analyze the association between moderate-to-vigorous PA (MVPA) and AP in adolescents, considering potential confounding variables of school setting and self-concept in adolescents. METHOD: The final sample was composed of 394 students (186 boys) with a mean age of 11.3 (SD = 0.8) years. The school grades were used as an indicator of AP. Measurements of body mass and stature were collected, and the body mass index was calculated and converted into z-score values. Maternal education, socioeconomic status, self-concept, and variables of the school setting were self-reported. MVPA and sedentary behavior (SB) were measured through accelerometry (GT3X and GT3X+; ActiGraph, Pensacola, Florida). Multiple linear regression was used for the association analyses, adopting p < .05. RESULTS: MVPA was inversely associated with global AP and mathematics only for girls: ß = -.105 (95% CI [-0.205, -0.006]; p = .038); ß = -.136 (95% CI [-0.261, -0.011]; p = .033). After adjusting for the school setting and self-concept, these significant associations disappear. DISCUSSION: MVPA was inversely associated with global AP and mathematics only for girls regardless of age, z-score body mass index, maternal education, socioeconomic status, and SB. However, after adjusting for school setting and self-concept, theses association disappear in mathematics and global AP, respectively. CONCLUSION: The device-measured MVPA was not associated with AP after controlling for important variables (school setting and self-concept).

Light-intensity physical activity patterns and associated factors in adolescents

Abstract Aims: This study aimed to measure light-intensity physical activity (LPA) patterns in adolescents according to weekdays and school period and investigated associations between LPA patterns and associated factors. Methods: This is a cross-sectional study with 388 students of both genders, selected from public schools from Londrina city, Parana state. LPA was measured using accelerometry for seven consecutive days and was analyzed by the time spent in very short (15 to 30 s), short (30 to 60 s), intermediate (1 to 3 min), and long bouts (≥ 3 min). Results: Approximately 22% of the total daily time was spent in LPA. The time in LPA accumulated in short or intermediate bouts was higher than the time accumulated in very short or long bouts (P < 0.05). Gender was associated with short (β= 2.180; 95% confidence interval [CI], 0.357 to 4.003) and intermediate bouts (β = 2.822; 95% CI, 0.681 to 4.964), girls presented higher daily time. Age was inversely associated with very short (β = −0.925; 95% CI, −1.676 to −0.175) and intermediate bouts (β = −1.985; 95% CI, −3.579 to −0.390). The total time in LPA and time accumulated in very short, short, and intermediate bouts was higher in the school period when compared to the non-school period (P < 0.05). Conclusion: It could be concluded that the LPA patterns are predominantly composed of time spent in bouts between 30 seconds and three minutes. Gender, age, and school period appear to influence the LPA pattern in adolescents.

Associations between strength, flexibility, and painful symptomology in university staff.

BACKGROUND: In the adult population, the work environment and physical fitness levels are directly related to the onset of musculoskeletal pain, repetitive strain injuries, and decreased blood circulation. Although low levels of muscle strength and flexibility may lead to a higher prevalence of pain, specific anatomic regions are poorly addressed. OBJECTIVE: To investigate the prevalence of musculoskeletal pain and the association between strength or flexibility and pain in university staff. METHODS: The sample was composed of 110 members of staff from a university in Guarapuava-PR. Body mass and height values were obtained, from which the BMI was calculated. The pain evaluation was performed by means of a questionnaire, analyzing the intensity, frequency, and anatomical region. The subjects were then submitted to strength (right and left hand grip, lumbar traction, lower limb traction) and flexibility tests (sit and reach test). RESULTS: The anatomical region with the highest prevalence of pain was the lumbar region (43.4%). When the association between the presence of pain and flexibility was performed, only the lumbar traction presented significant results, with the weakest group demonstrating pain (OR: 3.47 [1.27 - 9.49]). CONCLUSION: The results demonstrate that low levels of strength in the lumbar region are associated with the presence of painful symptomatology.

NEUROMUSCULAR FITNESS IN EARLY LIFE AND ITS IMPACT ON BONE HEALTH IN ADULTHOOD: A SYSTEMATIC REVIEW.

OBJECTIVE: To systematically review the literature to verify the relationship between neuromuscular fitness indicators in childhood/adolescence and bone strength variables in adulthood. DATA SOURCES: A systematic review was conducted in PUBMED, SCOPUS, SPORTDiscus, Web of Science, PsycINFO, LILACS, and SciELO, covering the entire period until March 2019. DATA SYNTHESIS: The search identified 1149 studies. After duplicity analysis and eligibility criteria, four studies were reported. In one study, baseline was childhood and, in the others, adolescence. In childhood, when adjusting the model for age and body mass index, a statistically significant relation was found for girls: standing long jump with quantitative ultrasound index (ß=0.11; p<0.05) and with speed of sound (ß=0.14; p<0.01). However, when controlling muscular performance in adulthood, the relationship was no longer significant. In adolescence, coefficients ranged from 0.16 for neuromotor battery and bone mineral density (BMD) in the lumbar region to 0.38 for hanging leg lift test and BMD of arms. The explained variance varied between 2% (bent arm hang for BMD total) and 12% (hanging leg-lift for BMD arms), therefore, a higher performance in neuromuscular fitness in adolescence was associated with better bone strength in adulthood. CONCLUSIONS: In adults, bone strength variables showed significant correlation from low to moderate magnitude with neuromuscular fitness indicators in adolescence, but not in childhood, after controlling for adult performance in neuromuscular fitness. However, there is limited evidence to support the neuromuscular fitness in early life as a determinant of bone strength in adulthood.

Association between sedentary behavior, obesity and hypertension in public school teachers.

The present study aimed to verify the prevalence and association of sedentary behavior and its breaks with obesity and cardiovascular risk factors in teaching professionals. The sample was composed by 245 public school teachers (186 women and 59 men), with a mean age of 45 yr. Sedentary behavior was evaluated by self-reported screen time in different devices (television, computer, cellphone/tablet), and sedentary breaks at work and leisure were assessed by a Likert scale (never, rarely, sometimes, often, always). Cardiovascular risk factors (overweight/obesity, abdominal obesity, blood pressure, and heart rate) were objectively collected by trained individuals in the work environment of the teachers. Logistic Binary Regression models were adjusted for confounding factors (age, sex, and socioeconomic status). The prevalence of sedentary behavior was 55.3% in the sample. High sedentary behavior was associated to abdominal obesity (OR=2.21 [CI=1.23-3.97]). No association was observed between sedentary breaks at work and independent variables, however teachers with high sedentary breaks at leisure time were less likely to present high blood pressure (OR=0.58 [CI=0.32-0.98]). In conclusion, high sedentary behavior was associated with abdominal obesity, and high sedentary breaks in leisure time were associated to lower chances of high blood pressure among public school teachers.