Search

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 (β = 0.077; 95% confidence interval, 0.001 to 0.55; β = 0.076; 95% confidence interval, 0.003 to 0.154; and β = 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.

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.

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 (β = 0.315; R2 = 0.14; P = 0.020) and persistence in sports participation (β = 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., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Batista et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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.

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.

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 (VO 2max ) 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 (β = -0.004; p = 0.001) and incongruent (β = -0.005; p = 0.004) stimulus-responses. Meanwhile, the variation in VO 2max over the three year-study had a significant impact on the reaction time of congruent (β = -0.006; p = 0.001) and incongruent (β = -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., (© 2022. The Author(s).)

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.

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 - 1 for boys and ≥36.63 ml.kg - 1 .min - 1 for 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.

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.

Background: Our aim was to analyze the association of self-reported mentally-passive and mentally-active sedentary behaviors with different patterns (bouts and breaks) of device-measured sedentary time in adolescents. Methods: This was a cross-sectional study conducted among 375 adolescents (177 boys) aged 1015 years. Total time, bouts and breaks of sedentary time were measured through accelerometers. Self-reported sedentary behavior in different activities was summed and divided into mentally-active (playing electronic games, studying and reading) and mentally-passive (watching TV, watching DVD, and using computer for leisure). Bayesian linear regression models were used for association analyses. Results: Only mentally-passive sedentary behaviors were positively associated with longer bouts [1-4 minutes: mean posterior distribution: -0.431 (95% credible interval: -0.745 to -0.114); =15 minutes: 0.641 (0.122 to 1.222)] and lower number of breaks [-0.138 (-0.228 to -0.044)] of device-measured sedentary time. Conclusion: Self-reported mentally-passive sedentary behaviors are associated with longer bouts and lower breaks of device-measured sedentary time., (© 2021 The Author(s).)

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: β = -.105 (95% CI [-0.205, -0.006]; p = .038); β = -.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).

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.

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 (β=0.11; p<0.05) and with speed of sound (β=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.

Objectives: To analyse the association of sedentary behaviour patterns with dietary and lifestyle habits among public school teachers., Design: Cross-sectional study., Participants: A sample of 245 teachers (186 women and 59 men) with mean age of 45.2 (±10.4) were randomly selected from public schools., Primary and Secondary Outcome Measure: Sedentary behaviour was assessed by hours spent watching television, computer and cellphone/tablet use and in sitting position. Sedentary breaks were reported in a Likert scale in domains of work and leisure time. Dietary habits were assessed by weekly consumption of fruits, vegetables, dairy products, fried foods, sweets, grains, cereals, white meat, soft drinks and snacks. Physical activity, smoking, alcohol consumption and socioeconomic status were assessed by using questionnaires., Results: The prevalence of high sedentary behaviour, high sedentary breaks at work and at leisure was 57.9%, 67.7% and 70.2% in the sample, respectively. No relationship was observed of high sedentary behaviour with dietary and lifestyle habits in adjusted analysis. However, high sedentary breaks at work were associated with high consumption of dairy products (OR=1.93 (CI 1.07 to 3.51)) and cereals (OR=2.49 (CI 1.05 to 5.92)) and with being high physically active (OR=2.57 (CI 1.14 to 5.77)). High sedentary breaks at leisure time were associated with high consumption of fruits (OR=2.33 (CI 1.28 to 4.23)) and vegetables (OR=1.91 (CI 1.05 to 3.49)) and with be high physically active (OR=2.34 (CI 1.03 to 5.35)). High sedentary breaks were associated with better dietary habits even among teachers with high sedentary behaviour., Conclusion: High sedentary breaks were associated with better dietary habits and with high levels of physical activity among public school teachers, even those with high sedentary behaviour., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

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.

The aim of this study was to systematically review the literature to verify the association between participation in sports (PS) in childhood and adolescence and physical activity (PA) in adulthood. A systematic search was conducted in the following databases: Medline (PUBMED), Web of Science, Scopus, and SPORTDiscus, LILACS and SciELO. All steps of the process followed the recommendations of the PRISMA FlowDiagram. After all the steps of the process, 29 articles were included for analysis. In general, only three of the studies analyzed found no relation between PS in childhood and adolescence and PA in adulthood. However, a positive relationship was found to be weak in only 7% of the studies, a moderate relation in 62% of the studies, and a strong relation in 21%. It was found that higher weekly frequencies of PS; persistence of at least three years of PS and, finally, the highest level of practice and/or competition reached were related to higher levels of PA in adulthood. Thus, it can be concluded that there is a positive association considered moderate to strong between PS in childhood and adolescence and PA in adulthood.

Background: The use of ecological momentary assessment (EMA) to measure sedentary behavior (SB) in children, adolescents, and adults can increase the understanding of the role of the context of SB in health outcomes., Objective: The aim of this study was to systematically review literature to describe EMA methodology used in studies on SB in youth and adults, verify how many studies adhere to the Methods aspect of the Checklist for Reporting EMA Studies (CREMAS), and detail measures used to assess SB and this associated context., Methods: A systematic literature review was conducted in the PubMed, Scopus, Web of Science, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and SPORTDiscus databases, covering the entire period of existence of the databases until January 2018., Results: This review presented information about the characteristics and methodology used in 21 articles that utilized EMA to measure SB in youth and adults. There were more studies conducted among youth compared with adults, and studies of youth included more waves and more participants (n=696) than studies with adults (n=97). Most studies (85.7%) adhered to the Methods aspect of the CREMAS. The main criteria used to measure SB in EMA were self-report (81%) with only 19% measuring SB using objective methods (eg, accelerometer). The main equipment to collect objective SB was the ActiGraph, and the cutoff point to define SB was <100 counts/min. Studies most commonly used a 15-min window to compare EMA and accelerometer data., Conclusions: The majority of studies in this review met minimum CREMAS criteria for studies conducted with EMA. Most studies measured SB with EMA self-report (n=17; 81.0%), and a few studies also used objective methods (n=4; 19%). The standardization of the 15-min window criteria to compare EMA and accelerometer data would lead to a comparison between these and new studies. New studies using EMA with mobile phones should be conducted as they can be considered an attractive method for capturing information about the specific context of SB activities of young people and adults in real time or very close to it., (©Catiana Leila Possamai Romanzini, Marcelo Romanzini, Mariana Biagi Batista, Cynthia Correa Lopes Barbosa, Gabriela Blasquez Shigaki, Genevieve Dunton, Tyler Mason, Enio Ricardo Vaz Ronque. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 15.05.2019.)

Objectives: The aim of the present study was to examine the stability of physical fitness, and the interrelationships among intra-individual changes in fitness and fatness among elementary school children., Methods: A longitudinal study was conducted among 372 adolescents (196 boys) and followed up over 3 years (from childhood to adolescence). Physical fitness was estimated using three indicators: cardiorespiratory fitness (through a 9-minute running test), flexibility (through a sit-and-reach test), and muscle resistance (through maximal abdominals in 1 minute). Body adiposity was obtained through triceps and subscapular skinfolds. Somatic maturation was assessed by the peak of height velocity. Kappa and Lin's tests of concordance as well as logistic regression analyses were conducted with P < 0.05 in STATA 15.1., Results: Tracking of physical fitness from childhood to adolescence was moderate for both sexes [boys: kappa = 0.441 (P < 0.001); LCCC = 0.591 (P < 0.001). Girls: kappa = 0.335 (P < 0.001); LCCC = 0.534 (P < 0.001)]. A larger increment in body fat was associated with a higher likelihood to decrease a tertile in physical fitness among boys [OR: 4.17 (95% CI: 1.31-13.22)] and with a lower likelihood to increase a tertile in physical fitness among both sexes [boys: OR = 0.25 (95% CI: 0.09-0.67); girls: OR: 0.37 (95% CI: 0.15-0.92)]., Conclusions: Health-related physical fitness has moderate tracking from childhood to adolescence. Increases in body adiposity from childhood to adolescence are associated with a reduction in physical fitness tertile., (© 2019 Wiley Periodicals, Inc.)

New technologies able to identify the sedentary behavior (SB), such as the Mobile Ecological Momentary Assessment (mEMA) still need to be investigated. The aim of this study was to describe SB in the physical, social, and environmental contexts and verify the agreement between the mEMA and accelerometry in the identification of SB in young adults. During 7 days, 123 young adults used concomitant mEMA and Actigraph wGT3xBT accelerometer. Data of 2262 mEMA prompts and respective count values in each minute (5 min previous to prompt) were included in the analyses. Descriptive and comparative statistics were used in analyses using the SPSS 20.0 software. The physical context (PC) at home was the highest occurrence of SB (46.3%) and the main activity was "watching TV/movies" (29.7%). The main social context (SC) related to SB was "staying alone" (49.6%). The main assertions related to the participants' environmental context (EC) were: "I appreciate the comfort of electronic devices when I am at home" (86.2%). mEMA identified the presence of SB in 78.1% of prompts, while accelerometry identified 70.9% (PABAK = 0.42). High values for the presence of SB were observed (sensitivity = 84%) and lower in the absence of SB (specificity = 38%). The study demonstrates the viability of mEMA use to obtain information about the occurrence of SB in contextual factors and good sensitivity to identify the presence of SB in young adults. The combined use of these methods is suggested in future studies about SB in young adults.

Purpose: To investigate the association between patterns of sedentary behavior and obesity indicators among adolescents., Methods: This was a cross-sectional study conducted among 389 adolescents (186 boys) aged 10-14 years. Body mass index, body fat (skinfolds), and waist circumference were adopted as outcomes. Sedentary behavior patterns (total time, bouts, and breaks) measured through accelerometry (GT3X and GT3X+; ActiGraph, Pensacola, FL) were adopted as exposures. Peak height velocity, moderate to vigorous physical activity (accelerometer), cardiorespiratory fitness (Léger test), sex, and chronological age were adopted as covariates. Linear regression models adjusted for covariates were used to determine associations between outcome and exposure variables., Results: The mean age of adolescents was 11.8 (0.7) years. Boys were more active than girls (P < .001). Accumulating shorter bouts (1-4 min) of sedentary behavior was negatively associated with body mass index (β = -0.050; 95% confidence interval [CI], -0.098 to -0.003) and waist circumference (β = -0.133; 95% CI, -0.237 to -0.028). Similarly, a higher number of breaks in sedentary behavior were negatively associated with body mass index (β = -0.160; 95% CI, -0.319 to -0.001) and waist circumference (β = -0.412; 95% CI, -0.761 to -0.064)., Conclusion: Shorter bouts of sedentary behavior (1-4 min) and a higher number of breaks of sedentary behavior were associated with lower adiposity. Our findings also suggest that breaking up sedentary time to ensure bouts of sedentary behavior are short might contribute to the prevention of obesity in adolescents.

Purpose: To analyze the relationship between engagement in sports in early life and bone variables among adults of both sexes., Methods: The sample was composed of 225 men and women. Demographic data were collected, and dual-energy X-ray absorptiometry was used to assess bone mineral density, bone mineral content, and lean soft tissue. Sports participation in early life was assessed by an interview including childhood and adolescence. Consumption of tobacco and alcohol was also assessed by interview and the habitual physical activity level by a pedometer., Results: Inactive men had bone mineral content around 11% lower than active men in childhood or adolescence, whereas for women, this difference represented around 14%. Active men had 74% less fat mass than inactive men in early life, and the difference was 67% for women. Early sports participation explained the differences in whole-body bone mineral content (16.8%, P-value = .005) and bone mineral density (8.8%, P-value = .015), as well as bone mineral density in lower limbs (18.9%, P-value = .001) among women., Conclusion: Adults engaged in sports in early life have higher bone mass than their inactive peers, especially women.

Background: This study aims to describe the regional prevalence and patterns of physical activity (PA) and sedentary behavior among Brazilian adolescents., Methods: Data from the Brazilian Scholar Health Survey, a nationally representative survey of ninth-grade adolescents [mean age: 14.29 y (14.27-14.29)] conducted in 2015 (n = 101,445), were used. Outcomes were television viewing, sitting time (ST), total PA, and active traveling collected via self-administered questionnaire. Information on frequency of physical education classes and type of school was collected from the school's director. Frequencies with 95% confidence intervals were used to determine the prevalence and patterns of outcomes., Results: Higher prevalence of PA (≥300 min/wk) and ST (>4 h/d) was found in Midwest (PA = 38.0%; ST = 44.5%), South (PA = 37.6%; ST = 50.1%), and Southeast (PA = 36.1%; ST = 49.3%) compared with Northeast (PA = 29.7%; ST = 36.9%) and North (PA = 34.4%; ST = 34.8%) regions of Brazil. ST was higher among adolescents from private schools (51.5%) than public schools (42.9%), whereas active traveling was greater among students of public schools than private schools (62.0% vs 34.4%). Most inequalities in outcomes between capital and interior cities were in the poorest regions., Conclusions: The results indicate that national plans targeting regional inequalities are needed to improve PA and to reduce sedentary behavior among Brazilian adolescents.

Warm-up has been shown to mediate numerous acute physiological alterations that have been purported to confer beneficial effects on performance. This study investigated the acute effects of different warm-up procedures on resistance training performance. Employing a randomized, counterbalanced crossover design, 15 men performed 3 exercises (4 sets of bench press, squat, and arm curl at 80% of 1RM) to failure in 4 conditions (control, specific, aerobic, and combined). Outcome measures included the sum of repetitions and a fatigue index measuring the decline between sets. There was no significant difference for the sum of repetitions or for fatigue index among conditions for the 3 exercises. Performance in the resistance training exercises was not influenced by warm-up.

The purpose of this study was to analyze the acute effect of static stretching on the performance of multiple sets in the bench press (BP) exercise. Fifteen men (26.2 ± 0.7 years, 72.4 ± 1.3 kg, 1.78 ± 0.1 m, 22.8 ± 0.3 kg·m) performed 4 sets of the BP exercise at 80% of 1 repetition maximum until concentric failure, both in the stretching condition (SC) and control condition (CC). The rate of force decline between the first and the fourth set was used as fatigue index. A randomized, counterbalanced, crossover design was performed with 48 hours between each session. Two static stretching exercises (pectoral and triceps brachii muscles) were performed in a single set before BP in SC, whereas in CC, subjects remained at rest for 150 seconds. For each stretching exercise, the muscle was held at the maximal stretched position for 30 seconds. No significant difference (p > 0.05) was identified for total repetitions performed in 4 sets (SC, 21.3 ± 0.7% vs. CC, 20.5 ± 0.7%) and in the fatigue index (SC, 75.5 ± 1.3% vs. CC, 73.2 ± 1.9%). The results suggest that the performance of multiple sets in the BP exercise does not seem to be influenced by previous static stretching.

The objective of this study was to develop count cut-points for three different accelerometer models: ActiGraph GT3X, RT3 and Actical to accurately classify physical activity intensity levels in adolescents. Seventy-nine adolescents (10-15 years) participated in this study. Accelerometers and oxygen consumption ([Formula: see text]) data were collected at rest and during 11 physical activities of different intensities. Accelerometers were worn on the waist and [Formula: see text] was measured by a portable metabolic system: Cosmed K4b2. Receiver operating characteristic (ROC) curves were used to determine cut-points. Cut-points for sedentary (SED), moderate-to-vigorous (MVPA) and vigorous-intensity physical activity (VPA) were 46, 607 and 818 counts·15s(-1) to the vertical axis of ActiGraph; 180, 757 and 1112 counts·15s(-1) to the vector magnitude of ActiGraph; 17, 441 and 873 counts·15s(-1) for Actical; and 5.6, 20.4 and 32.2 counts·s(-1) for RT3, respectively. For all three accelerometer models, there was an almost perfect discrimination of SED and MVPA (ROC >0.97) and an excellent discrimination of VPA (ROC>0.90) observed. Areas under the ROC curves indicated better discrimination of MVPA by ActiGraph (AUC=0.994) and Actical (AUC=0.993) when compared to RT3 (AUC=0.983). The cut-points developed in this study for the ActiGraph (vector magnitude), RT3 and Actical accelerometer models can be used to monitor physical activity level of adolescents.

The aim of this study was to analyze the validity of 4 regression equations to estimate the peak oxygen consumption (V[Combining Dot Above]O2peak) from the 20-m shuttle run test in adolescents aged 11-13 years. One hundred and fifteen adolescents, 61 boys (mean ± SD: age = 12.3 ± 0.9 years) and 54 girls (age = 12.1 ± 0.7 years) performed the 20-m shuttle run test and an incremental progressive maximal test for direct V[Combining Dot Above]O2peak analysis. Four linear regression equations were used to estimate the V[Combining Dot Above]O2peak: Barnett et al. (equation 1), Léger et al. (equation 2), Mahar et al. (equation 3), and Matsuzaka et al. (equation 4). For boys, only the V[Combining Dot Above]O2peak estimated by EQ3 did not differ from the value directly measured (p > 0.05). The EQ1, EQ2, and EQ4 underestimated the V[Combining Dot Above]O2peak, whereas the EQ3 overestimated, particularly in girls (p < 0.05). Large limits of agreement were found between the reference method and the 4 equations, with higher estimated values by EQ2 for boys (8.36 ± 15.24 mL·kg·min) and girls (2.45 ± 12.63 mL·kg·min). The highest correlation values were observed by EQ4 for boys (r = 0.80), EQ1 for girls (r = 0.72), and EQ3 for total sample (r = 0.80). The equations analyzed were not precise for individual V[Combining Dot Above]O2peak prediction; however, the EQ3 revealed better agreement, particularly for boys. Considering the data obtained in the boys and total sample, our results suggest that the EQ3 may provide the best predictive measure of V[Combining Dot Above]O2peak from the 20-m shuttle run test in adolescents aged 11-13 years.

Objectives: To evaluate the accuracy of three different cutoff points for the detection of high blood pressure in adolescents, given the strong relationship between overweight and high blood pressure levels., Methods: A total of 1,021 adolescents of both sexes were enrolled in the study, selected at random from public and private schools in Londrina, Brazil. Their body weight was measured using a digital balance, and their height with a portable stadiometer with a maximum extension of 2 meters. Arterial blood pressure was measured using an automatic apparatus. The capacity of body mass index to detect high blood pressure was gauged using ROC curves and their parameters (sensitivity, specificity, and area under the curve)., Results: The cutoff points proposed in a Brazilian standard exhibited greater accuracy (males: 0.636+/-0.038; females: 0.585+/-0.043) than the cutoff points proposed in an international (males: 0.594+/-0.040; females: 0.570+/-0.044) and a North-American standard (males: 0.612+/-0.039; females: 0.578+/-0.044)., Conclusions: The Brazilian proposal offered greatest accuracy for indicating high blood pressure levels.

The aim of this study was to determine the prevalence of cardiovascular risk factors in adolescents and to verify its association with age and gender. 644 high school students from public schools in the city of Londrina, Paraná State, Brazil, participated in the study. A two-step sampling process was used. Behavioral risk factors (physical inactivity, inadequate consumption of fruits and vegetables, and smoking) and biological risk factors (overweight and high blood pressure) were investigated. Nearly 90% of adolescents showed at least one risk factor. Inadequate consumption of fruits (56.7%) and vegetables (43.9%) and physical inactivity (39.2%) were the most prevalent risk factors. Prevalence rates for high blood pressure and overweight were 18.6 and 12.7%, respectively. Cardiovascular risk factors were more frequent among boys (PR = 1.20; 95%CI = 1.01-1.42). In conclusion, cardiovascular risk factors are a prevalent health issue among students in the city of Londrina.