Efficacy of School-Based Interventions for Improving Muscular Fitness Outcomes in Adolescent Boys: A Systematic Review and Meta-analysis

Abstract

Background It has been reported that boys' and girls' physical activity (PA) levels decline throughout adolescence. Boys are at risk of physical inactivity during adolescence; however, in intervention research, they are an under-represented group relative to girls. It is suggested that the school environment may be central to developing interventions that support adolescents in meeting the current PA guidelines. The aim of this systematic review and meta-analysis was to investigate the efficacy of school-based physical activity interventions for improving muscular fitness (MF) in adolescent males. Methods This systematic review and meta-analysis followed the preferred reporting systems for meta-analyses guidelines and was registered on PROSPERO (Registration number: CRD42018091023). Eligible studies were published in English within peer-reviewed articles. Searches were conducted in three databases, with an additional grey literature search in Google Scholar. Studies investigating MF outcomes were included. Results There were 43 data sets identified across 11 studies, from seven countries. Overall methodological quality of the studies was moderate-to-strong. Interventions targeting MF evidenced a small-to-medium effect (g = 0.32, CI 0.17, 0.48, p < 0.00). Subgroup analyses of MF delivery method resulted in small-to-medium effects: upper limb MF measures (g = 0.28, 95% CI − 0.02, 0.58, p = 0.07), lower limb MF measures (g = 0.28, 95% CI 0.09, 0.68, p = 0.03), combined MF activities (g = 0.24, 95% CI − 0.04 to 0.49, p = 0.05), plyometric activities (g = 0.39, 95% CI 0.09, 0.68, p = 0.01), body weight (g = 0.27, 95% CI − 0.10, 0.65, p = 0.15), and traditional MF methods (g = 0.43, 95% CI 0.09, 0.78, p = 0.01). Conclusions School-based interventions which aimed to increase MF outcomes in adolescent boys demonstrated smallto-moderate effects. Traditional and plyometric methods of resistance training appear to be the most effective form of PA delivery in adolescent males. More quality research is required to assess the impact of MF delivered in the school environment to inform future intervention design.It is recommended that adolescents engage in a minimum of 60 min of moderate-to-vigorous physical activity (MVPA) per day with muscle and bone strengthening exercise Key PointsMF interventions delivered in a school-based environment demonstrated small-to-moderate effects in adolescent boys.MF delivered in a traditional manner, such as weight machines and free weights, may have a greater effect on enhancing MF than other forms of MF delivery.Plyometric forms of MF delivery demonstrated significant homogeneous effects and require further quality research to assess their application in the school environment.

The SIMAC study: A randomized controlled trial to compare the effects of resistance training and aerobic training on the fitness and body composition of Colombian adolescents

“…Overall, intensity was increased across the 16 weeks such that during weeks 1-5; 16-20 RM with 30 seconds rest between sets, in weeks 6-10; between 8-14 RM, with between 30-120 seconds inter-set rest, and in weeks [11][12][13][14][15][16]; between 6 and 12 RM with 30-120 seconds inter-set rest. For the multigym exercises (Table 1) load was adjusted by re-estimated participant's 1 RM according to the load and repetitions performed during the last session of the training block, whereas exercises in the free-weight and functional/proprioceptive categories were progressed in a more informal way by estimating adding load to try and maintain participants within the target repetition range.…”

“…Little is known however regarding the implementation and outcomes of resistance training interventions in low-middle income countries. The majority of studies have been conducted in high-income countries [15,16], and a recent systematic review of resistance training programs in schools showed that only 1 of 11 studies was implemented in an low-middle income country [15]. School represents the ideal setting for the delivery of resistance training as it provides opportunities to introduce students to novel forms of activity they might not be exposed to outside of school [17].…”

Effects of School-Based Physical Activity Programs on Health-Related Physical Fitness of Korean Adolescents: A Preliminary Study

“…The recommended minimum level of physical activity for adolescents is moderate to vigorous activity for at least 20 min per session, three times a week [ 7 ]. Several studies have proposed school-based physical activity programs to encourage physical activity in adolescents, as schools are an ideal environment for implementing physical activity programs, and these programs are known to be effective in promoting physical fitness [ 8 , 9 , 10 ]. In addition, adolescents are most active during school days, and schools provide access to physical activities in a manner that is independent of academic background or socioeconomic status [ 8 , 11 ].…”

“…Several studies have proposed school-based physical activity programs to encourage physical activity in adolescents, as schools are an ideal environment for implementing physical activity programs, and these programs are known to be effective in promoting physical fitness [ 8 , 9 , 10 ]. In addition, adolescents are most active during school days, and schools provide access to physical activities in a manner that is independent of academic background or socioeconomic status [ 8 , 11 ]. Furthermore, school-based physical activities ensure the exposure of a maximum number of adolescents to the intervention, and it is relatively easy to increase the number of adolescents participating in these activities.…”

Secular Trends in the Achievement of Physical Activity Guidelines: Indicator of Sustainability of Healthy Lifestyle in Czech Adolescents

“…However, according to Booth, Rowlands, and Dollman [13], there is little evidence of the decrease in PA among children and adolescents. Moreover, interventions for improving muscular fitness in adolescent boys demonstrated small-to-moderate effects [14].…”