Analysis of different domains of physical activity with health-related quality of life in adults: 2-year cohort.

BACKGROUND: It is estimated that, worldwide, 9% of deaths occur as a result of insufficient physical activity (PA) practice. Practicing PA can prevent and/or reduce the deleterious effects of different types of diseases and can improve general health aspects related to health-related quality of life (HRQoL). PURPOSE: To analyze the relationship of different PA domains with different HRQoL domains over a two-year period. METHODS: This is an observational study with a two-year longitudinal design. The sample, composed of adults, was selected from a randomization of the streets of the different regions (north, south, east, west and center) covering individuals from all areas of the city. To assess the practice of PA, the Baecke questionnaire was used. The instrument Medical Outcomes Study SF-36-Item Short Form Health Survey was used to assess the HRQoL domains. Linear regression models were used to analyzed the association of different PA domains with changes in HRQoL. Multivariate statistical models were adjusted for gender, age, socioeconomic status, marital status, the respective PA score at baseline, smoking, body mass index, and morbidity. RESULTS: 331 adults were evaluated. There was a decrease in the practice of PA in the occupational domain and an increase in the leisure/locomotion domain. Regarding HRQoL, there was an increase in the scores of body pain and mental health, and a decrease in scores of general health, vitality, social aspects and emotional aspects. The PA practice in the occupational domain was inversely related to functional capacity (ß = - 7.2 [CI 95% - 13.0; - 1.4]). The practice of PA through sports in leisure time was positively associated with vitality (ß = 5.5 [CI 95% 0.2; 10.7]) and mental health (ß = 15.2 [CI 95% 6.8; 23.7]). PA practice during leisure and locomotion was inversely associated with functional capacity (ß = - 5.68 [CI 95% - 10.7; - 0.6]) and positively associated with vitality ß = 4.8 [CI 95% 0.8; 8.7]) and mental health (ß = 8.4 [CI 95% 2.0; 14.9]). The total PA practice was inversely associated with functional capacity (ß = - 3.8 [CI 95% - 6.5; - 1.2]) and positively associated with pain in the body (ß = 4.9 [CI 95% 0.3; 9.4]), vitality (ß = 2.9 [CI 95% 0.7; 5.0]) and mental health (ß = 5.7 [CI 95% 2.2; 9.2]). CONCLUSIONS: It is suggested that practicing PA continuously within a period of two years can positively affect some physical aspects and some mental aspects related to HRQoL, but not all of them. A strategy for public policy actions is to explore these variables by domain and thus detect the real needs and improvements that can be made for the population.

Association of parents' physical activity and weight status with obesity and metabolic risk of their offspring.

Our aim was to analyze the joint association of parental characteristics and offspring obesity indicators with metabolic risk in adolescents. A cross-sectional study was carried out with 972 adolescents and their parents. We observed that overweight adolescents who have a normal weight mother show lower metabolic risk in comparison with their counterparts with overweight mothers. In conclusion, mother's weight status moderates the relationship between offspring' obesity indicators and metabolic risk in adolescents.

Association of parents' physical activity and weight status with obesity and metabolic risk of their offspring / Associação do status de atividade física e peso dos pais com os indicadores de obesidade e risco metabólico dos filhos

Abstract Our aim was to analyze the joint association of parental characteristics and offspring obesity indicators with metabolic risk in adolescents. A cross-sectional study was carried out with 972 adolescents and their parents. We observed that overweight adolescents who have a normal weight mother show lower metabolic risk in comparison with their counterparts with overweight mothers. In conclusion, mother's weight status moderates the relationship between offspring' obesity indicators and metabolic risk in adolescents.

Resumo Nosso objetivo foi analisar a associação combinada entre características dos pais e indicadores de adiposidade dos filhos com o risco metabólico em adolescentes. Foi realizado estudo transversal com 972 adolescentes e seus pais. Observamos que adolescentes com sobrepeso que possuem mãe com peso normal apresentaram menor risco metabólico em comparação com seus pares com mães que apresentam sobrepeso. Concluímos que o status de peso da mãe modera a relação entre indicadores de obesidade e risco metabólico dos adolescentes.

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).

Exercise Duration Affects Session Ratings of Perceived Exertion as a Function of Exercise Intensity.

Session ratings of perceived exertion (sRPE) are considered a practical marker of whole session exercise intensity, but its relationship to exercise volume has remained unclear. We analyzed the effects of exercise duration at different intensities on overall and differentiated sRPE. Sixteen males (Mage = 22.6, SD = 2.2 years; Mheight = 176.4, SD = 5.8 cm; Mweight = 74.0, SD = 5.9 kg; and Mbody fat = 9.4, SD = 2.2%) performed 15 and 30 minute runs at speeds associated with RPE levels of two (weak), three (moderate) and five (strong) on Borg's CR-10 scale during a previous graded exercise test. We used Foster's scale to access sRPE 30 minutes after each trial. Significant increases in sRPE were found with increases in running speed (p < 0.01, ηG2 = 0.48) and duration (p < 0.01, ηG2 = 0.16), with a significant speed X duration interaction (p < 0.01, ηG2 = 0.10). In addition, there was a significant effect for sRPE type (p = 0.01, ηG2 = 0.05) in that overall sRPE was slightly lower than sRPE differentiated to legs and higher than sRPE differentiated to breathing through the trials. Changes in sRPE from 15 to 30-minute trials were minimal for the slow speed and weak sRPE (Cohen´s dz = 0.04 - 0.25) but got higher at the moderate (Cohen´s dz = 0.88 - 1.06) and strong (Cohen´s dz = 1.94 - 2.50) speeds and sRPEs. Thus, exercise duration affects sRPE in an intensity dependent manner. This finding has practical relevance for prescribing exercise, suggesting a need to target specific training loads or aims to optimize trainees' retrospective perceptions of the exercise experience.

Independent and Combined Effects of Weight Status and Maturation on Aerobic Fitness in Adolescent School-Aged Males.

Batista, MB, Valente-dos-Santos, J, Duarte, JP, Sousa-e-Silva, P, Coelho-e-Silva, MJ, Werneck, AO, Ohara, D, Cyrino, ES, and Ronque, ERV. Independent and combined effects of weight status and maturation on aerobic fitness in adolescent school-aged males. J Strength Cond Res 34(9): 2663-2671, 2020-This study aimed to examine the independent and combined effects of pubertal and weight status on concurrent measurements of peak oxygen (V[Combining Dot Above]O2peak) in school-aged adolescent males. The final sample included 49 boys (12.3 ± 0.8 years). V[Combining Dot Above]O2peak was derived from an incremental progressive maximal protocol using a motorized treadmill. In addition, maximal oxygen uptake was estimated from a 20-m shuttle run test. Static allometric models were obtained as an alternative to performance output per unit of size descriptors. Weight status had a significant effect on V[Combining Dot Above]O2peak using simple ratio standards per unit of body mass (BM) with adolescents classified as overweight and obese (OWOB) attaining lower values of V[Combining Dot Above]O2peak. A similar trend was noted for the allometric models adopting body mass (ml·kgBM·min), stature (L·m·min), and fat-free mass (FFM; ml·kgFFM·min). Findings also suggest the influence and interaction of pubertal and weight status on absolute values of V[Combining Dot Above]O2peak. Considering the data obtained, linear equations to estimate V[Combining Dot Above]O2peak from the 20-m shuttle run test should not be applied to boys who are OWOB because it will produce inaccurate assessments of cardiorespiratory fitness and penalize those who are heavier. Equations for V[Combining Dot Above]O2peak prediction need to be specific for pubertal status and preferably consider FFM as a body size descriptor.

Agreement Between GT3X Accelerometer and ActivPAL Inclinometer for Estimating and Detecting Changes in Different Contexts of Sedentary Time Among Adolescents.

BACKGROUND: This investigation aimed to analyze the agreement between the GT3X accelerometer and the ActivPAL inclinometer for estimating and detecting changes in sedentary behavior of different contexts among adolescents. METHODS: Secondary data from an intervention using standing desks in the classroom conducted within 2 sixth-grade classes (intervention [n = 22] and control [n = 27]) were used. The intervention took place over 16 weeks, with activity assessments (ActivPAL and GT3X) being performed 7 days before and in the last week of the intervention. Baseline information from both groups was considered for cross-sectional analysis (209 valid days), while data from 20 participants (intervention group) were used for longitudinal analysis. RESULTS: The authors observed that GT3X overestimated sedentary time at school (16.8%), after school (13.5%), and during weekends (7.3%) compared with ActivPAL (P < .05). Outside the school (after school [r = -.188] and on weekends [r = -.260]), there was a trend to higher overestimation among adolescents with less sedentary behavior. Longitudinally, the GT3X was unable to detect changes resulting from an intervention in school hours (ActivPAL = -34.7 min·9 h-1 vs GT3X = +6.7 min·9 h-1; P < .05). CONCLUSIONS: The authors conclude that GT3X (cut-point of <100 counts·min-1) overestimated sedentary time of free-living activities and did not detect changes resulting from a classroom standing desk intervention in adolescents.

Allometric scaling of aerobic fitness outputs in school-aged pubertal girls.

BACKGROUND: This study aimed to determine the allometric exponents for concurrent size descriptors (stature, body mass and fat-free mass) and also to examine the contribution of chronological age and pubertal status combined with above mentioned size descriptors to explain inter-individual variability in the peak of oxygen uptake (VO2peak) among girls during circumpubertal years. METHODS: The final sample included 51 girls (10.7-13.5 years). VO2peak was derived from an incremental progressive maximal protocol using a motorized treadmill. Anthropometry included body mass, stature and skinfolds. Measurements were performed by a single trained observer. Sexual maturation was assessed as self-reported stage of pubic hair (PH) development. Static allometric models were explored as an alternative to physiological output per unit of size descriptors. Allometry also considered chronological age and sexual maturation as dummy variable (PH2 vs. PH3 and PH3 vs. PH4). RESULTS: Scaling coefficients for stature, body mass and fat-free mass were 1.463 (95%CI: 0.476 to 2.449), 0.516 (95%CI: 0.367 to 0.666) and 0.723 (95%CI: 0.494 to 0.951), respectively. The inclusion of sexual maturation increased explained variance for VO2peak (55% for PH2 vs. PH3 and 47% for PH3 vs. PH4). Body mass was identified as the most prominent body size descriptor in the PH2 vs. PH3 while fat-free mass was the most relevant predictor combined with PH3 vs. PH4. CONCLUSIONS: Body mass and fat-free mass seemed to establish a non-linear relationship with VO2peak. Across puberty, inter-individual variability in VO2peak is explained by sexual maturation combined with whole body during early puberty and by sexual maturation and fat-free mass during late puberty. Additional studies need to confirm ontogenetic allometric models during years of maximal growth.

The importance of an integrative view of behaviors adopted during the 24 hours of the day in physical activity and exercise interventions studies / A importância de uma visão integrativa dos comportamentos adotados nas 24 horas do dia em estudos de intervenção com atividade física e exercício

Abstract Given the reduced proportion of the 24 hours of the day spent with moderate to vigorous physical activities, there has been a recent appreciation of integrative and compositional approaches of the different behaviors adopted throughout the day for interpretations of health outcomes. This study points out the importance of integrating sleep time, sedentary behavior and physical activities of different intensities in the interpretation of results of physical activity and exercise interventions. We believe that this is a crucial strategy for better understanding the effects of interventions as well as for scientific progress in the area.

Resumo Considerando a reduzida proporção das 24 horas do dia ocupada com atividades físicas de intensidade moderada ou vigorosas, há uma valorização recente de abordagens integrativas e composicionais dos diferentes comportamentos adotados ao longo do dia para as interpretações de desfechos em saúde. Aqui chamamos a atenção para a importância da integração do tempo de sono, do tempo em comportamento sedentário e de atividades físicas de diferentes intensidades na interpretação de resultados de intervenções em atividade física e exercício. Acreditamos ser essa uma estratégia crucial para o melhor entendimento dos efeitos das intervenções, bem como para o progresso científico da área.

Comparison of Skillful vs. Less Skilled Young Soccer Players on Anthropometric, Maturation, Physical Fitness and Time of Practice.

This study compared maturation, body composition and physical fitness between youth soccer athletes with different technical skills levels. Sixty-two young athletes (11-17 years) were categorized dichotomously in more skilled (n=31) and less skilled (n=31) groups based on 3 specific technical tests (Dribbling Speed Test [DST], Shuttle Dribble Test [SDT] and Slalom Dribble Test [SLDT]). Chronological and skeletal age, time of practice, body composition and 4 physical fitness tests were performed for comparisons. As expected, the 3 technical tests were correlated (r=0.47-0.54, P<0.05). More skilled subjects in DST and SDT showed (respectively) higher time of practice (effect size [ES]=0.72 and 0.90), and greater performance sit-ups (ES=1.23 and 0.81), squat jump (ES=1.10 and 1.08), countermovement jump (ES=1.11 and 1.10), and Yo-Yo test (ES=1.17 and 1.40) compared to the less skilled subjects (P<0.05). However, more skilled subjects in SLDT showed greater performance (P<0.05) only in the squat jump (ES=0.67) and Yo-Yo tests (ES=0.83). The results suggest that technical performance is associated with greater time of practice and some physical capabilities. Moreover, the DST and SDT tests seem to be good options to discriminate technical performance in youth soccer athletes.

Cardiorespiratory fitness effect may be under-estimated in 'fat but fit' hypothesis studies.

BACKGROUND: Both cardiorespiratory fitness and body fat have been independently related to metabolic syndrome in adolescents; however, the strength of these relationships seems to be dependent on the outcome composition. AIM: To analyse the relationship between cardiorespiratory fitness and body fat combined with different indicators of metabolic risk in adolescents. SUBJECTS AND METHODS: The sample was composed of 957 adolescents (58.7% girls). Cardiorespiratory fitness was obtained using the 20-metre shuttle run test and skinfold thickness was collected for body fat estimation. Metabolic risk score was calculated from waist circumference, systolic and diastolic blood pressure, glucose, HDL cholesterol and triglycerides measurements and an alternative outcome without the central obesity indicator was adopted. Chronological age and somatic maturity were used as covariates. RESULTS: Higher metabolic risk was observed in the highest fat/lowest fit adolescents (p < .05), regardless of sex and outcome. In the regression models, for full metabolic risk score, body fat presented higher coefficients compared to cardiorespiratory fitness in both sexes (boys: 0.501 vs -0.097; girls: 0.485 vs -0.087); however, in the metabolic risk without waist circumference, the coefficients became closer (boys: 0.290 vs -0.146; girls: 0.265 vs -0.120), with a concomitant decrease in body fat and increase in cardiorespiratory fitness coefficients. CONCLUSION: These findings suggest that body fat is strongly related to cardiovascular risk, but, when the outcome is calculated without the central obesity indicator, cardiorespiratory fitness becomes more related to metabolic risk.

Association between risk behaviors and adiposity indicators in adolescents from Southern Brazil: A methodological approach.

The aim of this study was to analyze the association between risk behaviors and adiposity indicators in adolescents and to discuss some methodological aspects related to this relationship. We evaluated 1,321 adolescents (55.2% female) aged 10-16 years. Relative body fat (%fat) by measurement of triceps and subscapular skinfold thickness and waist circumference (WC) were used as total and central adiposity indicators, respectively. Physical inactivity, time spent in front of the TV, the consumption of soda and/or chocolate, alcohol, and tobacco smoking were analyzed as risk behaviors. Information about the socioeconomic status (categorized into three levels) and nutritional status of the mother (overweight or normal weight) were used as adjustment factors in the analyses of prevalence ratio (PR) of the outcomes and their associated 95% confidence intervals (95% CI). The chi-square test and Poisson regression were used for statistical analyses. Low associations were found between risk behaviors and adiposity indicators. Tobacco smoking was the most positively correlated behavior with adiposity in girls (%fat: PR = 1.61; 95% CI = 1.04-2.47; WC: PR = 1.90; 95% CI = 1.17-3.08) and in adolescents whose mothers were normal weight (%fat: PR = 2.31; 95% CI = 1.33-4.03; WC: PR: 2.31; CI: 1.19-4.46). Additionally, as an important methodological issue, we highlighted the assessment of risk behaviors in adolescents as crucial to producing more robust evidence on the subject. Of the investigated behaviors, we concluded that tobacco smoking is the behavior most associated with adiposity indicators.

Correlates of sports practice, occupational and leisure-time physical activity in Brazilian adolescents.

OBJECTIVES: To analyze the relationship between different physical activity (PA) domains and sociodemographic, psychological, behavioral and biological factors in Brazilian adolescents. METHODS: 1,220 adolescents (55.1% female) aged between 10 and 16 years-old participated in this study. The Baecke questionnaire was used to evaluate different PA domains, namely occupational, sports and leisure-time. Socioeconomic status, number of siblings, friendships satisfaction, mother's and father's PA level and previous experience with sports were self-reported. Cardiorespiratory fitness, waist circumference, and somatic maturity were estimated by objective indicators. Linear regression was used for the main statistical analysis. RESULTS: The variables consistently related to all of the PA domains were gender (boys more active), friendship satisfaction (positive with sports and leisure-time PA and negative with occupational PA) and cardiorespiratory fitness (positive). There were also domain-specific relationships for occupational (number of siblings [ß = 0.02] and father's PA [ß = 0.13]), sport practice (previous experience with sports [ß = 0.33], waist circumference [ß = 0.01] and somatic maturity [ß = -0.12]) and leisure-time PA (chronological age [ß = -0.15], mother's PA [ß = 0.47] and previous experience with sports [ß = 0.17]). CONCLUSIONS: The different domains of PA are related to specific variables in adolescence. This information may be helpful in formulating strategies for physical activity promotion, particularly in adolescents from low-to-middle income countries.

Sedentary Behavior and Light Physical Activity Are Associated with Brachial and Central Blood Pressure in Hypertensive Patients.

BACKGROUND: Physical activity is recommended as a part of a comprehensive lifestyle approach in the treatment of hypertension, but there is a lack of data about the relationship between different intensities of physical activity and cardiovascular parameters in hypertensive patients. The purpose of this study was to investigate the association between the time spent in physical activities of different intensities and blood pressure levels, arterial stiffness and autonomic modulation in hypertensive patients. METHODS: In this cross-sectional study, 87 hypertensive patients (57.5 ± 9.9 years of age) had their physical activity assessed over a 7 day period using an accelerometer and the time spent in sedentary activities, light physical activities, moderate physical activities and moderate-to-vigorous physical activities was obtained. The primary outcomes were brachial and central blood pressure. Arterial stiffness parameters (augmentation index and pulse wave velocity) and cardiac autonomic modulation (sympathetic and parasympathetic modulation in the heart) were also obtained as secondary outcomes. RESULTS: Sedentary activities and light physical activities were positively and inversely associated, respectively, with brachial systolic (r = 0.56; P < 0.01), central systolic (r = 0.51; P < 0.05), brachial diastolic (r = 0.45; P < 0.01) and central diastolic (r = 0.42; P < 0.05) blood pressures, after adjustment for sex, age, trunk fat, number of antihypertensive drugs, accelerometer wear time and moderate-to-vigorous physical activities. Arterial stiffness parameters and cardiac autonomic modulation were not associated with the time spent in sedentary activities and in light physical activities (P > 0.05). CONCLUSION: Lower time spent in sedentary activities and higher time spent in light physical activities are associated with lower blood pressure, without affecting arterial stiffness and cardiac autonomic modulation in hypertensive patients.

Nível de atividade física, indicadores clínicos e qualidade de vida de pessoas vivendo com HIV/AIDS / Level of physical activity, clinical indicators and quality of life for people living with HIV/AIDS

A Síndrome da Imunodeficiência Adquirida (AIDS), transmitida pelo Vírus da Imunodeficiência Humana (HIV), é uma doença crônica com expectativa de vida cada vez mais ampliada para estas pessoas. A atividade física apresenta-se como uma ferramenta terapêutica na manutenção e melhora da saúde e da qualidade de vida da população vivendo com HIV/AIDS. No entanto, pouco se sabe acerca da influência da atividade física na saúde e na qualidade de vida desses indivíduos. Nesse sentido o objetivo do presente estudo foi associar o nível de atividade física, indicadores clínicos e qualidade de vida em pessoas vivendo com HIV/AIDS na região central do Estado do Rio Grande do Sul, Brasil. Para tanto, foram avaliados 72 indivíduos de ambos os sexos, quanto ao nível de atividade física, perfil socioeconômico, antropométrico, clínico e sua qualidade de vida. Como resultados, verificou-se que aproximadamente 72% da amostra era insuficientemente ativa fisicamente. O tempo de diagnóstico foi a única variável associada ao nível de atividade física (p = 0,04), com maior prevalência de fisicamente ativos (43,2%) entre os indivíduos com menor tempo de diagnóstico (≤ 84 meses). O domínio referente à função sexual foi o que apresentou maiores escores em todas as análises. Os indivíduos ativos fisicamente apresentaram maior escore (p = 0,015) apenas no domínio "preocupação com a medicação". Em conclusão, o tempo de diagnóstico, a função sexual e a preocupação com a medicação foram os únicos itens que apresentaram associação com o nível de atividade física em pessoas vivendo com HIV/AIDS.

The Acquired Immunodeficiency Syndrome (AIDS), transmitted by the Human Immunodeficiency Virus (HIV), is a chronic disease with a life expectancy increasingly expanded to their peoples. Physical activity is presented as a therapeutic tool in maintaining and improving the health and quality of life of people living with HIV / AIDS. However, little is known about the influence of physical activity on health and quality of life of these individuals. In this paper the aim to associate the level of physical activity with socioeconomic, anthropometry, clinical factors and quality of life of individuals living with HIV/AIDS in the central region of Rio Grande do Sul (RS) - Brazil. Were evaluated seventy-two subjects of both sexes and living with HIV/AIDS were evaluated regarding their socioeconomic status, anthropometry, clinical profile and quality of life. Results: Approximately 72% of the sample was classified as insufficiently active. "Time of contamination" was the only variable associated to physical activity (p = 0.04), with higher prevalence of physically active individuals (43.2%) among subjects with lower time of diagnosis (≤ 84 months). Domain regarding sexual function showed highest scores for all analysis. Physically active subjects had higher score on "concern with medication". In conclusion, the time of diagnosis, sexual function and concern about their medication were the only items that were associated with the level of physical activity among people living with HIV / AIDS.

Validação dos limiares do acelerômetro Actical para a determinação do comportamento sedentário e da intensidade da atividade física em adolescentes / Validation of Actical accelerometer thresholds to determine the sedentary behavior and physical activity intensity in adolescents

O objetivo do estudo foi verificar a validade de limiares para determinação de atividades sedentárias e atividades físicas de intensidade moderada a vigorosa para o acelerômetro Actical em adolescentes. Setenta e nove adolescentes (idade média 12,5 anoss; 50,5% meninos) foram monitorados por acelerometria e calorimetria indireta em repouso e durante quatro atividades sedentárias e sete atividades físicas com diferentes intensidades. Escores de METs e limiares específicos para counts do acelerômetro Actical propostos por Colley e Tremblay (CT), Puyau et al. (PU) e Evenson et al (EV) foram utilizados para classificar as atividades sedentárias (SED), moderadas a vigorosas (MOD-VIG) e vigorosas (VIG). A calorimetria indireta foi utilizada como método de referência e a validade dos limiares estimada por meio de curvas ROC (Receiver Operating Characteristic Curves) e dos coeficientes de concordância de Kappa. Os limiares proposto por PU e EV apresentaram excelente acurácia de classificação das SED (ROC ≥ 0,96; κ ≥ 0,90). Os limiares de PU, EV e CT apresentaram acurácia elevada para classificação das atividades MOD-VIG (ROC = 0,89, 0,88 e 0,86, respectivamente; κ = 0,77, 0,75 e 0,73, respectivamente). A acurácia de classificação das VIG por meio dos limiares de EV e CT foi boa (ROC = 0,90 e 0,85;  = 0,69 e 0,67) e significantemente superior àquela apresentada pelo limiar de PU (ROC = 0,74 e  = 0,51). Conclui-se que limiares atualmente disponíveis para o acelerômetro Actical possuem boa validade para a determinação da

The aim of this study was to verify the validity of cut off points for the Actical accelerometer to estimate sedentary, moderate and vigorous physical activities among adolescents. Seventy-nine adolescents (mean age 12.5 years; 50.5% boys) were monitored by accelerometry and indirect calorimetry at rest and during four sedentary activities and eleven physical activities performed at different intensities. METs scores and specific thresholds for the Actical accelerometer counts proposed by Colley and Tremblay (CT), Puyau et al. (PU) and Evenson et al (EV) were used to classify sedentary activities (SED), physical activities from moderate to vigorous (MOD-VIG) and vigorous (VIG). The validity of thresholds was tested by means of Receiver Operating Characteristic Curves (ROC) and Kappa agreement coefficients. PU and EV thresholds showed excellent accuracy to classify SED (ROC ≥ 0.96, κ ≥ 0.90). Accuracy of the cut points of PU, EV and CT for MOD-VIG were high (ROC = 0.89, 0.88 and 0.86, respectively, κ = 0.77, 0.75 and 0.73, respectively). Accuracy to classify VIG through EV and CT thresholds was good (ROC = 0.90 and 0.85, k = 0.69 and 0.67) and significantly higher than that shown by the PU threshold (ROC = 0 .74 k = 0.51). It was concluded that thresholds currently available for the Actical accelerometer have good validity to estimate sedentary activities and physical activity from MOD to VIG intensities among adolescents.

Calibration of ActiGraph GT3X, Actical and RT3 accelerometers in adolescents.

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.

Static stretching and performance in multiple sets in the bench press exercise.

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.

Validity of equations for estimating V[combining dot above]O2peak from the 20-m shuttle run test in adolescents aged 11-13 years.

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.

Pressão arterial elevada e obesidade abdominal em adolescentes / High blood pressure and abdominal obesity in adolescents

OBJETIVO:Analisar a associação entre obesidade abdominal e pressão arterial elevada em adolescentes da rede pública de ensino da região metropolitana da cidade de Londrina (PR). MÉTODOS: Constituiu-se uma amostra de 656 adolescentes com idades entre dez e 13 anos. Foram realizadas análises antropométricas de massa corporal, estatura e circunferência de cintura, além da aferição da pressão arterial de repouso. Para análise e comparação dos dados, foram aplicados Mann-Whitney e o teste t de Student. Também foram analisadas as possíveis associações entre pressão arterial e circunferência de cintura por meio do teste do qui-quadrado. RESULTADOS: Foram identificadas associações entre obesidade abdominal e pressão arterial elevada em ambos os sexos (RP 2,7; IC95 por cento 1,8-4,2). Além disso, verificou-se que, independentemente do grupo etário, a obesidade abdominal associa-se com valores mais elevados de pressão arterial. CONCLUSÕES: A obesidade abdominal está associada à ocorrência de aumento da pressão arterial em adolescentes.

OBJECTIVE:To analyze the association between abdominal obesity and high blood pressure among adolescents of public schools from Londrina (PR), Brazil. METHODS: The sample was composed by 656 adolescents with age ranging from ten to 13 years old. The following measures were taken: body mass, height, waist circumference and blood pressure at rest. Mann-Whitney and Student's t-test were used to compare and analyze numerical variables. The chi-square test analyzed the association between blood pressure and waist circumference. RESULTS: Association between abdominal obesity and high blood pressure was present in both genders (PR 2.7; 95 percentCI 1.8-4.2). Abdominal obesity was associated with higher blood pressure independently of age. CONCLUSIONS: Abdominal obesity was associated to high blood pressure in adolescents.