Background: School-based physical activity interventions evaluating the effect on academic performance usually includes children. We aimed to investigate the effect of a nine-month, school-based physical activity intervention titled School in Motion (ScIM) on academic performance in adolescents. Methods: Thirty secondary schools in Norway were cluster-randomized into three groups: the Physically active learning (PAL) group (n = 10), the Don’t worry – Be Happy (DWBH) group (n = 10) or control (n = 10). Target dose in both intervention groups was 120 min/week of additional PA during school hours. Parental consent was obtained from 2084 adolescent students (76%). Standardized national tests in reading and numeracy was conducted at baseline and at the end of the intervention. We used linear mixed model to test intervention effects. We found significant intervention effects in numeracy and reading among students in both interventions when compared with controls. Results: The mean difference in change in numeracy was 1.7 (95% CI: 0.9 to 2.5; Cohen’s d = 0.12) and 2.0 (95% CI: 1.4 to 2.7; Cohen’s d = 0.23) points in favour of students in the PAL and DWBH intervention, respectively. Similar results were found for reading, where the mean difference in change was 0.9 (95% CI 0.2 to 1.6; Cohen’s d = 0.06) and 1.1 (95% CI 0.3 to 1.9; Cohen’s d = 0.18) points in favour of students in the PAL and DWBH intervention, respectively. When conducting intention to treat analysis with imputed data the estimates were attenuated and some no longer significant. Conclusion: The ScIM study demonstrates that two different school-based PA interventions providing approximately 120 min of additional PA weekly over nine months, significantly improved numeracy and reading performance in 14-year old students compared with controls. However, the results should be interpreted with caution as the effect sizes reported were very small or small and the estimates were attenuated when conducting intention to treat analysis. Despite this, our results are still positive and suggest that PA interventions are viable models to increase academic performance among adolescents. Trial registration: Retrospectively registered (25/01/2019): NCT03817047.

Aim: The purpose of the present study was to 1) provide normative data quantifying the physical fitness level and body mass index of 13–15-year-old Norwegian adolescents using a multi-component fitness assessment, and 2) compare the physical fitness of Norwegian teenagers with available European and International fitness data. Methods: 1059 adolescents (529 males, 530 females) from 12 public schools in Kristiansand were invited to testing at age 13, 14, and 15 years (Grades 8–10). Test participation was 75%–80%. The participants performed objectively anthropometrical measures (height and weight) and six field-based physical fitness tests. Results and Conclusions: As expected, sex differences in physical fitness expanded from age 13 to 15. Strength and power increased more in males than females. Aerobic capacity increased slightly in males while remaining stable or tending to decline in females. Balance and gross motor coordination improved identically in males and females from age 13 to 15. Compared to European and International reference data, the sample performed superior in endurance and balance, slightly above median in lower-body strength, but inferior in flexibility.

One perspective on leadership that has recently gained increased attention in sport is identity leadership; however, research on elite sport teams is still in its infancy. Thus, the main purpose of this research is to investigate identity leadership in elite team sports in relation to task cohesion, and subsequently to explore the mediating role of the intra-team communication dimensions of acceptance and distinctiveness. A cross-sectional design was employed and 441 elite athletes from division 1 and division 2 in handball and ice hockey participated in the present study. Structural equation modeling was used to assess relationships between identity leadership and task cohesion, and the mediating role of acceptance and distinctiveness. Results revealed that identity leadership positively predicted task cohesion, and that this relationship was mediated by intra-team communication acceptance. In conclusion, findings in the present study expand our understanding of performance-related benefits of identity leadership in elite sport.