Effects of Teasing in Physical Education Classes, Self-efficacy, and Physical Activity on Adolescents’ Self-esteem / [El efecto del hostigamiento en las clases de educación física, la autoeficacia y la actividad física en la autoestima de los adolescentes]

Objective: To investigate the differences between boys and girls in the present variables, and assess the possible associations between self-esteem and teasing in school physical education classes, self-efficacy, and physical activity among adolescents. Method: The sample included 944 adolescents aged 14 to 19 years (mean =16.52, SD = 1.12, 53.6% male), enrolled in public high schools in Florianópolis, Santa Catarina, Brazil. Information was collected on age, body mass index, physical activity level, self-efficacy, teasing experiences in physical education classes, and self-esteem (dependent variable). Self-esteem was assessed using the Rosenberg Self-esteem Scale. Results: Adolescents had a mean self-esteem score of 28.71 (out of 40), with boys having higher scores than girls (29.66 vs. 27.61, p < .001). In both sexes, adolescents who reported lower levels of teasing in physical education classes had higher self-esteem. Boys with high self-efficacy and higher levels of physical activity had higher self-esteem scores. Conclusion: Experiencing teasing in school physical education classes was a predictor of self-esteem in adolescents of both sexes, and self-efficacy and physical activity were predictors of self-esteem in boys.(AU)

Objetivo: Investigar las diferencias entre chicos y chicas en las variables de estudio, así como averiguar la posible asociación entre autoestima y el hostigamiento en las clases de educación física, autoeficacia y actividad física en adolescentes. Método: Se contó con una muestra de 944 de entre 14 y 19 años (media = 16.52, DT = 1.12, el 53.6% hombres) que estudiaban en centros escolares de Florianópolis, Santa Catarina, Brasil. Se recogió información sobre edad, índice de masa corporal, nivel de actividad física, autoeficacia, hostigamiento en las clases de educación física y autoestima (variable dependiente). La autoestima se midió mediante la Escala de Autoestima de Rosenberg. Resultados: La autoestima media de los adolescentes era 28.71 (de un máximo de 40), siendo más elevada la de los chicos que la de las chicas (29.66 vs. 27.61, p < .001). En ambos sexos la autoestima de los adolescentes que declaraban menos hostigamiento en educación física era superior. Los chicos que tenían una mayor autoeficacia y mayor actividad física tenían puntuaciones más elevadas en autoestima. Conclusión: Experimentar hostigamiento en las clases de educación física predecía la autoestima de los adolescentes de ambos sexos; la autoeficacia y la actividad física predecían la autoestima en los chicos.(AU)

Secular trends in body image dissatisfaction and associated factors among adolescents (2007-2017/2018).

OBJECTIVE: To assess secular trends in body image dissatisfaction and associated factors among adolescents over a 10-year period (2007-2017/2018). METHODS: The sample included 1,479 (2007, n = 531; 2017/2018, n = 948) high school adolescents of both sexes, aged 14 to 18 years, of schools in a city in southern Brazil, in 2007 and 2017/2018. Data were collected on sex, age, physical activity (IPAQ, short form), anthropometric measurements (body weight, height, and triceps and subscapular skinfolds), and body image dissatisfaction (figure rating scale). The variables were compared with Independent samples t-test and Mann-Whitney U-test. The associations between sex and other variables were examined with chi-square test, and the factors associated with body image were identified with multinomial logistic regression. RESULTS: Most adolescents were dissatisfied with their body image in 2007 (65,2%) and 2017/2018 (71,1%). The prevalence of body dissatisfaction increased by 9.2% over the 10-year period, particularly dissatisfaction with thinness (21.3%). After stratification by sex, in 2017/2018 sample, dissatisfaction with overweight was 46.1% greater in boys, and dissatisfaction with thinness was 66.9% greater in girls. Factors found to be significantly associated with body image dissatisfaction were physical activity level, and body adiposity. CONCLUSIONS: There was a secular trend toward increased body image dissatisfaction in both sexes. Future efforts should go beyond scientific production, in public and private environments aimed at increasing awareness of health issues related to body care in the physical, psychological, and environmental domains.

Agreement and validity between body fat estimated by skinfold measurement and air displacement plethysmography in adolescents / Concordância e validade entre a gordura corporal estimada por medidas de dobras cutâneas e pletismografia por deslocamento de ar em adolescentes

ABSTRACT Objective: Assess the agreement and validity between relative body fat percentages estimated using anthropometric measurements and air displacement plethysmography (ADP). Methods: A cross-sectional study was conducted on 118 adolescents (60 females) aged 10 to 14 years (x̄=12.19, sd=1.18). Adolescents were classified as eutrophic or with overweight according to body mass index (body weight/height2) (x̄=20,12, sd=3,56). Measurements of skinfold thickness (triceps and medial calf) were collected and used to estimate relative body fat by the Slaughter equation. ADP was used as a reference method for the estimation of relative body fat. Agreement between body fat measurement methods (anthropometry × ADP) was analyzed by the Bland-Altman method. The mean error (ME) was calculated by subtracting the body fat percentage estimated by the Slaughter equation from the body fat percentage estimated by ADP. Validity was tested with the concordance correlation coefficient (CCC). Results: There was no agreement between the methods, regardless of sex and weight status. For boys with overweight (ME = 4.52; p = 0.007), eutrophic girls (ME = 6.37; p < 0.001), and girls with overweight (ME = 5.55; p < 0.001), the Slaughter equation resulted in overestimation of body fat compared with ADP. Skinfold equations did not demonstrate validity when compared with ADP. Conclusion: Slaughter's skinfold equations did not demonstrate agreement and validity compared with ADP in either sex or weight status. Skinfold equations should be used with caution and, whenever possible, in combination with other body composition indicators.

RESUMO Objetivo: Avaliar a concordância e validade entre os percentuais de gordura corporal estimados usando medidas antropométricas e pletismografia por deslocamento de ar (PDA). Métodos: Um estudo transversal foi conduzido em 118 adolescentes (60 meninas) com idade entre 10 e 14 anos (x̄=12,19, dp=1,18). Os adolescentes foram classificados como eutróficos ou com sobrepeso de acordo com o índice de massa corporal (peso/altura2) (x̄=20,12, dp=3,56). Medidas de dobras cutâneas (tríceps e panturrilha medial) foram coletadas e utilizadas para estimar a gordura corporal relativa pela equação de Slaughter. A PDA foi utilizada como método de referência para a estimativa da gordura corporal relativa. A concordância entre os métodos de medida de gordura corporal (antropometria × PDA) foi analisada pelo método de Bland-Altman. O erro médio (EM) foi calculado subtraindo o percentual de gordura corporal estimado pela equação de Slaughter do percentual de gordura corporal estimado pela PDA. A validade foi testada com o coeficiente de correlação de concordância (CCC). Resultados: Não houve concordância entre os métodos, independente do sexo e status de peso. Para meninos com excesso de peso (EM = 4,52; p = 0,007), meninas eutróficas (EM = 6,37; p < 0,001) e meninas com excesso de peso (EM = 5,55; p < 0,001), a equação de Slaughter resultou em superestimação da gordura corporal comparada com PDA. As equações de dobras cutâneas não demonstraram validade quando comparadas ao PDA. Conclusão: As equações de dobras cutâneas de Slaughter não demonstraram concordância e validade em comparação com PDA em ambos os sexos ou status de peso. As equações de dobras cutâneas devem ser utilizadas com cautela e, sempre que possível, acompanhada de outros indicadores de composição corporal.

Relationship between body composition and bone mass in normal-weight and overweight adolescents.

Adolescence is a period characterized by large accumulation of bone mass. Body composition is an important determinant of bone mass. This study aimed to assess the relationship of bone mass with lean mass (LM) and fat mass (FM) in normal-weight and overweight adolescents with consideration of sex, sexual maturation and physical activity covariates. A total of 118 adolescents (60 girls and 58 boys) aged between 10 and 14 years participated in the study. Individuals were classified as normal weight or overweight according to body mass index. Bone mineral density (BMD), bone mineral content (BMC), LM, and FM were measured by dual-energy X-ray absorptiometry. In normal-weight adolescents, LM (ß = 0.725, p < 0.001) and FM (ß = 0.185, p = 0.019) were associated with lumbar spine BMC, whereas in overweight adolescents only LM (ß = 0.736, p < 0.001) was associated with lumbar spine BMC. Furthermore, in the normal-weight group, FM and LM were associated with total body less head BMD (LM, ß = 0.792, p < 0.001; FM, ß = 0.257, p = 0.007) and lumbar spine BMD (LM, ß = 0.553, p < 0.001; FM, ß = 0.199, p < 0.035). In the overweight group, only LM was associated with total body less head BMD (ß = 0.682, p < 0.001) and lumbar spine BMD (ß = 0.528, p < 0.001). LM was the main predictor of bone mass in normal-weight and overweight adolescents. FM was associated with bone mass in normal-weight adolescents only. LM may be considered an important and useful marker in adolescents, when investigating bone health in this population. Activities that promote LM gain to reduce the risk of bone fractures and diseases in adulthood are recommended.

Body image dissatisfaction in adolescents: Comparison with physical activity, teasing and social support.

This study aimed to compare the adolescents' body dissatisfaction with physical activity, teasing during physical activity and social support. Participants were 938 Brazilian adolescents aged 15-19 years. Study variables were investigated through questionnaires. There was no difference in body dissatisfaction among adolescents who practiced and did not practice physical activity, but among the former, those who had been teased had greater body dissatisfaction. Also, adolescents who had a relative or friend to talk, in addition to giving and receiving affection, more frequently, presented lower body dissatisfaction. Stratifying the sample by gender, the results were similar in females but were not significant in males.