João Paulo de Aguiar Greca

Physical activity and screen time in children and adolescents in a medium size town in the South of Brazil

Abstract Objective: To analyze the associations between sex and age with behaviour related to physical activity practice and sedentary behaviour in children and adolescents. Methods: A cross-sectional study with 480 (236 boys) subjects enrolled in a public school in the city of Londrina, in the south of Brazil, aged 8–17 years. Measures of physical activity, sports practice and screen times were obtained using the Physical Activity Questionnaire for Older Children. The Mann–Whitney U test was used to compare variables between boys and girls. The Chi squared test was used for categorical analysis and Poisson regression was used to identify prevalence. Results: Girls (69.6%; PR=1.05 [0.99–1.12]) spent more time with sedentary behaviour than boys (62.2%). Boys (80%; PR=0.95 [0.92–0.98]) were more physically active than girls (91%). Older students aged 13–17 showed a higher prevalence of physical inactivity (91.4%; PR=1.06 [1.02–1.10]) and time spent with sedentary behaviour of ≥2h/day (71.8%; PR=0.91 [0.85–0.97]) when compared to younger peers aged 8–12 (78.7 and 58.5%, respectively). Conclusions: The prevalence of physical inactivity was higher in girls. Older students spent more screen time in comparison to younger students.

PHYSICAL EDUCATION CLASSES AND HEALTH OUTCOMES IN BRAZILIAN STUDENTS

ABSTRACT Objective: To analyze the association between participation and physical activity during Physical Education classes with health outcomes in Brazilian students. Methods: 681 Brazilian students (50.5% female) aged 10 to 17 years participated in this cross-sectional study. Independent variables analyzed were participation and physical activity during Physical Education classes, both assessed using a self-report questionnaire. The outcomes were: cardiorespiratory fitness (20-meter Shuttle Run test), muscle strength (Push-up test), overweight and obesity (body mass index) and high blood pressure. Statistical analysis was conducted by Poisson regression to estimate the prevalence ratio (PR) and 95% confidence intervals (95%CI) adjusted for confounding variables (age, sex, parental education, physical activity and sedentary behavior), considering the complex sample design. Results: Participation in Physical Education classes was not associated with any of the studied variables. Being active during Physical Education classes was associated with achieving health related criteria for cardiorespiratory fitness (PR=1.34, 95%CI 1.16-1.55) and muscle strength (PR=1.36, 95%CI 1.09-1.71). The same did not occur for overweight (PR=1.04, 95%CI 0.95-1.14), obesity (PR=1.02, 95%CI 0.91-1.05), or high blood pressure (PR=0.98, 95%CI 0.90-1.06). Conclusions: Students who reported being active during classes presented a higher likelihood to achieve the health criteria for cardiorespiratory fitness and muscle strength. However, classes traditionally offered in Brazil do not protect students from overweight, obesity, or high blood pressure.

Effects of audiovisual stimuli on psychological and psychophysiological responses during exercise in adults with obesity

ABSTRACT The present experiment sought to further understanding of the effects of personalised audiovisual stimuli on psychological and psychophysiological responses during exercise in adults with obesity. Twenty-four participants (Mage = 28.3, SD = 5.5 years; MBMI = 32.2, SD = 2.4) engaged in self-paced exercises on a recumbent cycle ergometer and three conditions (sensory stimulation [ST], sensory deprivation [DE], and control [CO]) were administered. Perceptual (attentional focus and perceived exertion), affective (affective state and perceived activation), and psychophysiological (heart rate variability) parameters were monitored throughout the exercise bouts. A one-way repeated measures analysis of variance was used to compare self-reported and psychophysiological variables (main and interaction effects [5 Timepoints × 3 Conditions]). The results indicate that ST increased the use of dissociative thoughts throughout the exercise session (ηp2 = .19), ameliorated fatigue-related symptoms (ηp2 = .15) and elicited more positive affective responses (ηp2 = .12) than CO and DE. Accordingly, personally-compiled videos are highly effective in ameliorating exertional responses and enhancing affective valence during self-paced exercise in adults with obesity. Audiovisual stimuli could be used during the most critical periods of the exercise regimen (e.g., first training sessions) when individuals with obesity are more likely to focus on fatigue-related sensations.

Sedentary Behavior During School Recess in Southern Brazil

The aim of this study was to assess sedentary behavior during school recess in Brazilian boys and girls. The study included 455 students (233 boys and 222 girls), aged 8 to 17 years, enrolled in a public school in the city of Londrina, Brazil. All data was collected using questionnaires. Logistic regression with odds ratio and confidence interval (95%) was used to measure the relationship between sedentary behavior and sex, age, weight, screen time, and economic status. There was a high prevalence (40.7%) of sedentary behavior in this sample, with girls (aged 8 to 17 years) more likely than boys (54.5% vs. 27.5%, respectively) and older students (13–17 years) more likely than younger students (8–12 years) to engage in sedentary behavior (49.6% vs. 30.1%, respectively). These findings, and their broad implications for health and for interventions to increase physical activity, are discussed in light of past literature.

O sobrepeso e a obesidade não estão associados com a pressão arterial elevada em jovens praticantes de esportes

Resumo O objetivo do estudo foi analisar a associacao entre o sobrepeso e a obesidade com a pressao arterial elevada (PAE), de acordo com a pratica esportiva de jovens. Participaram do estudo 636 jovens de 10 a 17 anos da cidade de Londrina-PR. Foram analisadas as variaveis sexo, idade, escolaridade paterna, comportamento sedentario, pratica esportiva, estado nutricional e pressao arterial. A regressao de Poisson foi utilizada para estimar a razao de prevalencia (RP) e os intervalos de confianca de 95%. Jovens com sobrepeso e obesidade apresentaram maiores prevalencias de PAE, comparados aos eutroficos, quando analisadas a amostra total (25,7 e 29,5 vs 15,2%) e os nao praticantes de esportes (29,7 e 33,3 vs 15,1%), o mesmo nao ocorrendo com os praticantes de esportes (17,1 e 18,2 vs 15,5%). Foram encontradas associacoes positivas entre o sobrepeso e a obesidade com a PAE na amostra total (RP = 1,60, 1,02-2,52 e 1,93, 1,15-3,25) e nos jovens nao praticantes de esportes (RP = 1,80, 1,05-3,14 e 2,15, 1,10-4,16). Para os jovens praticantes de esportes nao foram encontradas associacoes entre sobrepeso e obesidade com a PAE (RP = 1,01, 0,36-2,82 e 1,09, 0,48-2,48). O excesso de peso nao se associou com a PAE em jovens praticantes de esportes, sugerindo protecao cardiovascular nos jovens com sobrepeso e obesidade.The aim of this study was to analyze the association between overweight and obesity with high blood pressure (HBP) according to sports practice in young people. Took part in this study 636 young people aged 10 to 17 years of Londrina, Parana State, Brazil. Sex, age, parental education, sedentary behavior, sports practice, nutritional status and blood pressure were analysed. Poisson regression was used to estimate the prevalence ratio (PR) and 95% confidence intervals. Overweight and obesity young people showed higher prevalence of HBP compared to eutrophics when analysed the total sample (25,7 e 29,5 vs 15,2%) and non sport practitioners (29,7 e 33,3 vs 15,1%), which did not occur with sports practitioners (17,1 e 18,2 vs 15,5%). Positive associations were found between overweight and obesity with HBP in total sample (PR = 1,60, 1,02-2,52 and 1,93, 1,15-3,25) and on non sport practitioners (RP = 1,80, 1,05-3,14 and 2,15, 1,10-4,16). For young people sports practitioners were not found associations between overweight and obesity with HBP (PR = 1,01, 0,36-2,82 and 1,09, 0,48-2,48). Weight excess was not associated with HBP in young people sports practitioners, suggesting cardiovascular protection in young people with overweight and obesity.

Impacto de 24 semanas de treinamento com pesos sobre a composição corporal de idosas

Introduction: Aging is related to alterations on the organism, such as a reduction on muscular mass and an increase of body fat, which can compromise the quality of life of old people. Thus, weight training has been recommended as an alternative to attenuate these reductions. Objective: To investigate the impact of a 24-week strength training program on body composition of elderly women. Methods: Twenty-two women were equally divided in training (TG) and control groups (CG). The TG was submitted to strength training, three times a week and the CG into stretching classes, two times a week. Body composition was evaluated by bioelectrical impedance. Results: CG presented a statistically significant reduction in the fat free mass, total body water and metabolic basal ratio. The TG did not present any changes in these variables (P>0.05). Conclusion: strength training can contribute to the maintenance of the body compositions components.