Search

This cross-sectional study investigated the association between health-related quality of life (HRQoL), cardiorespiratory fitness (CRF) and muscular fitness in 14-year-old adolescents.Norwegian adolescents (N = 1985) carried out a 10-min running test to assess cardiorespiratory fitness and three different muscular fitness tests (handgrip, sit-ups, and standing broad jump) and answered the KIDSCREEN-27 questionnaire to provide HRQoL data. Linear-mixed effect models were applied to detect relationships among the variables.Running-test results were positively associated with higher scores in the following KIDSCREEN domains: physical well-being, psychological well-being, autonomy and parent relationships, and school environment (β = 0.01-0.04; p .01 for all). Performance in sit-ups test was positively associated with higher scores in three out of five KIDSCREEN domains: physical well-being (β = 0.31; p .001), social support and peers (β = 0.16; p = .023), and school environment scores (β = 0.19; p = .006). An inverse association was found between the handgrip test results and the score on psychological well-being domain (β = - 0.10; p = .013).The associations between HRQoL and physical fitness were trivial (abdominal strength and handgrip strength) to small (CRF) but confirmed that earlier findings from children also are applied to adolescents. Explosive strength in the lower body showed no association with HRQoL. Further research should investigate the direction of causality.Clinicaltrials.gov ID nr: NCT03817047. Registered 01/25/2019 'retrospectively registered'.

Background Studies indicate that health-related components of physical fitness are associated with mental health outcomes. However, research is scarce concerning this relationship in young adolescents in general and non-existent in Norwegian populations specifically. The aim of the study was to examine whether body composition, muscular strength and cardiorespiratory fitness were associated with self-reported mental health in Norwegian adolescents. Methods Adolescents from four regions of Norway (n = 1486; mean age = 13.9; girls = 50.6%) participated. Self-reported mental health (psychological difficulties) was measured by completing the Strengths and Difficulties Questionnaire. Cardiorespiratory fitness was assessed with an intermittent running test; muscular strength was assessed by measuring handgrip strength, standing broad jump and sit-ups; and body composition was assessed by calculating body mass index from weight and height. Linear mixed effects models were conducted to assess the associations between the health-related components of physical fitness and psychological difficulties. School clusters were included as random effects and all models were controlled for sex, socioeconomic status and birthplace (domestic or foreign). Results Body composition was not associated with psychological difficulties. Muscular strength was independently associated with psychological difficulties, but when all independent variables were entered in the fully adjusted model, only cardiorespiratory fitness was associated with psychological difficulties. Conclusions There was a small but significant inverse association between cardiorespiratory fitness and levels of psychological difficulties in Norwegian adolescents. The results suggest that muscular strength is not associated with psychological difficulties in adolescents, when controlling for cardiorespiratory fitness. Future research should focus on the prospective association between physical fitness components and mental health outcomes in adolescents. Trial registration The study is registered in ClinicalTrials.gov ID nr: NCT03817047. Retrospectively registered January 25, 2019.

Purpose To investigate the effects of two school-based physical activity interventions on mental health in Norwegian adolescents. Methods Students from 29 lower secondary schools in Norway (n = 2084; 14–15 years; 49% female) were cluster-randomized into either a control group or one of two intervention groups (M1 and M2). Two interventions based on different theoretical frameworks aimed to increase physical activity in school by approximately 120 min per week, throughout a 29-week intervention period. M1 consisted of 30 min physically active learning, 30 min physical activity and one 60 min physical education lesson. M2 consisted of one physical education lesson and one physical activity lesson, both focusing on facilitating students’ interest, responsibility and social relationships. The self-report version of the Strengths and Difficulties Questionnaire was used to assess mental health. Physical activity was measured by accelerometry. Linear mixed effects models were used to examine the effects of the interventions. Results No effects were found for the overall study population. Interaction effects warranted subgroup analyses: M1 showed favorable results in the subgroup with the highest levels of psychological difficulties at baseline (b = −2.9; −5.73 to −0.07; p = .045) and in the immigrant subgroup (b = −1.6; −3.53 to 0.27; p = .093). M2 showed favorable results in the immigrant subgroup (b = −2.1; −4.36 to 0.21; p = .075). Conclusions The two interventions did not improve mental health in the full study population. However, results indicated beneficial effects among immigrants and those with poor mental health at baseline. More research is needed due to missing values and the results should therefore be interpreted with caution.

PurposeThis paper evaluates the implementation of a school-based physical activity intervention and discusses how the intervention outcomes can be influenced by the implementation.Design/methodology/approachIn four of the nine lower secondary schools in which the intervention was conducted, the authors examined implementation fidelity, adaptation, quality, responsiveness and dose received. The authors conducted focus group interviews with teachers (n = 8) and students (n = 46) and made observations. Dose delivered was examined quantitatively, with weekly registrations.FindingsResults showed that two out of four schools made few and positive adaptations, implemented the intervention with high fidelity and quality and responded positively. Four main factors were found to influence implementation: frame factors, intervention characteristics, participant characteristics and provider characteristics.Research limitations/implicationsA cross-sectional design was used and may not represent implementation throughout the whole school year.Practical implicationsIn terms of large-scale implementation, the intervention may be generalizable. However, intervention criteria such as adequate facilities and a flexible timetable may be unattainable for some schools. The intervention can be adapted without compromising its purpose, but adaptations should be a result of cooperation between students and teachers.Originality/valueProcess evaluations on this topic are rare. This study adds to a limited knowledge base concerning what factors may influence implementation of school-based physical activity interventions for adolescents.