Objective: To examine the associations between self-reported screen time and symptoms of stress, anxiety, and depression in adolescents.

Introduction: Low levels of cardiorespiratory fitness (CRF) are associated with a greater risk of metabolic syndrome (MetS) in adolescence. In this sense, it is important to verify the strength of this association and the certainty that this evidence can be recommended. Objective: The objective of this paper is to summarize, through a systematic review and meta-analysis, the evidence available to verify the association between CRF and MetS in adolescents. Methods: PubMed, Embase, CINAHL, SPORTDiscus, LILACS, and Web of Science were searched until 20 August 2024. The risk of bias in each study was assessed via the AXIS tool, and the certainty of the evidence was assessed via the GRADE system. For the meta-analysis, the odds ratio (OR) was calculated with a 95% confidence interval. Results: Nine studies (7077 participants), all with a low risk of bias, were included in the systematic review. There was a high certainty of evidence that adolescents with low CRF have significantly greater odds of developing MetS (OR = 3.63 [CI 95%, 2.54 to 5.20]). The odds increase for low vs. moderate (OR = 4.23 [CI 95%, 2.64 to 6.78]) and low vs. high (OR = 8.03 [CI 95%, 3.20 to 20.18]) CRF are considered separately. The effect does not change according to the type of test used to assess CRF (p = 0.51). Conclusions: There is high certainty of evidence that adolescents with low CRF levels have significantly greater odds of developing MetS; therefore, it is essential that intervention strategies be designed to increase CRF in this population.

O objetivo do presente estudo foi verificar os efeitos de 12 semanas de um programa para promoção da atividade física nos indicadores de saúde mental de adolescentes. A amostra foi composta por adolescentes de ambos os sexos com idades entre 12 e 15 anos, os quais foram alocados em grupo intervenção ou grupo controle. O programa de intervenção incluía os seguintes componentes: sessões de atividade física na escola; incentivo a prática de atividade física fora do ambiente escolar; orientações sobre estilo de vida saudável. Os indicadores de saúde mental analisados ​​foram: sintomas de ansiedade e depressão, qualidade do sono e bem-estar psicológico. Os efeitos da intervenção nas variáveis ​​de resultados foram analisados ​​mediante ANOVA para medidas repetidas. A comparação intergrupos foi realizada pela análise de covariância. Foi adotado um nível de significância de p<0,05. Após 12 semanas, a intervenção em grupo apresentou diminuição significativa da pontuação média do sono (diferença média: -0,96, IC 95%: -1,8; -0,09), sintomas de ansiedade (diferença média: -1,7, IC 95%: -2,9; -0,64) e depressão (diferença média:-1,5, IC 95%: -2,5; -0,56) em comparação aolinha de base. Nas comparações intergrupos, foi observado um efeito significativo favorável à intervenção em grupo para os sintomas de depressão (-2,39; IC 95%: -4,68; -0,11). Para o controle do grupo, não foram identificados diferenças nos indicadores de saúde mental entre os momentos. Conclui-se que 12 semanas de intervenção de um programa para a promoção da atividade física promoveu uma melhora significativa nos indicadores de saúde mental nos adolescentes do grupo de intervenção.

Health-related quality of life (HRQoL) is a multidimensional construct that encompasses physical, emotional, psychological, and social domains, according to an individual’s perception. Studies have indicated that lifestyle-related factors, such as engaging in physical activity (PA), reducing screen time (ST), and maintaining adequate sleep duration, may contribute to improved HRQoL in adolescents. The present study aimed to examine the associations of the 24 h movement behaviors (PA, ST, and sleep duration) with physical and psychological well-being, and HRQoL in adolescents. This study included 746 adolescents of both sexes, aged 11 to 15 years, enrolled in public schools. Sleep duration was assessed through a specific question related to habitual bedtime and wake-up time. ST was evaluated using a question regarding the daily time spent using recreational electronic devices. PA was measured using accelerometers (ActiGraph GT3X-BT). The KIDSCREEN questionnaire was used to assess physical and psychological well-being and HRQoL. Generalized linear models were used for statistical analysis. Significant associations were observed between meeting sleep duration recommendations and higher HRQoL scores (β = 1.05, 95% CI: 1.01–1.08), as well as psychological well-being (β = 1.07, 95% CI: 1.03–1.11). Additionally, adherence to ST recommendations was significantly associated with higher physical well-being scores (β = 1.07, 95% CI: 1.01–1.14). Concerning the combination of adherence to guidelines, meeting both sleep duration and ST recommendations was significantly associated with higher HRQoL scores (β = 1.08, 95% CI: 1.02–1.15), physical well-being (β = 1.11, 95% CI: 1.03–1.21), and psychological well-being (β = 1.09, 95% CI: 1.01–1.18). The findings of this study highlight the importance of adhering to the 24 h movement guidelines, which may contribute to improved adolescent well-being.

Participation in regular physical activity (PA) is associated with numerous health benefits, including improvement in adolescents’ mental health. The current study aimed to assess the effects of a 12-week physical activity intervention on psychological symptoms of adolescents. The sample of this controlled randomized study was composed by 150 adolescents aged 12 to 15 years old. PA intervention is an adaptation of the ActTeens Program, which includes structured PA sessions delivered during Physical Education classes. The Strengths and Difficulties Questionnaire (SDQ) was used to measure psychological symptoms. To analyze the effects of the intervention on psychological symptoms, generalized estimating equations (GEEs) models were constructed. After 12 weeks, there were no significant intervention effects for emotional problems (mean difference: −0.14; 95% IC: −1.1–0.82), conduct problems (mean difference: 0.14; 95% IC: −0.6–0.8), attention deficit/hyperactivity disorder (mean difference: −0.66; 95% IC: −1.4–0.1), peer problems (mean difference: 0.2; 95% IC: −0.6–1.0), prosocial behavior (mean difference: 0.00; 95% IC: −0.8; 0.8) and overall mental health score (mean difference: 0.15; 95% IC: −2.0; 2.3). No improvement in psychological symptoms was observed after 12 weeks of PA intervention. Future studies should explore how PA in different dimensions and contexts may impact positively on adolescents’ mental health.