Daily Mile programme.

Two reviews [20, 23] examined the effectiveness of this intervention, Breslin and their colleagues observed significant variability in outcomes across studies. Specifically, Breslin et al. reported one intervention session led to a significant increase in MVPA, with the intervention group achieving 10.67±2.74 minutes of MVPA compared to 0.44±0.95 minutes in the control group. Another study within the same review [23] noted a significant increase in PA levels after eight months, showing a daily increase of 9.1 minutes of MVPA in the intervention group. Regarding physical fitness, six primary studies in Breslin’s review documented a notable improvement in the intervention group versus the control group, although comparing results was challenging due to the varied fitness tests used.

Overall, Breslin and colleagues concluded that sustained participation in the Daily Mile leads to increased MVPA and physical fitness among school-aged children, without significant impacts on academic performance or BMI. Only one study highlighted a short-term enhancement in mental health [23]. Similar results were reported by [20]. However, they also reported some implementation barriers for “The Daily Mile programme” such as repetitive nature, time constraints associated with competing curriculum demands, and inadequate facilities regularly necessitate the adaptation and development of the original Daily Mile intervention format by schools and teachers [20]. It should be noted that Breslin et al review and Hanna et al review included largely the same primary studies and the quality assessment for included studies conducted by Breslin et al revealed that one study was excellent, six were good, five were fair and none of them was poor quality.

Active-break intervention.

Two systematic reviews [21, 25], evaluated the effectiveness of this intervention, Carrasco-Uribarren et al, found a significant improvement in both PA and MVPA, levels. Six included studies in [25] review, recorded a significant increase in in-school PA (SMD = 0.46; 95% CI: 0.28, 0.64; I2: 52%). Furthermore, five studies recorded a significant increase in MVPA (MD = 3.20; 95% CI: 3.06, 3.35; I²: 0%), however, the reduction was not significant for sedentary behavior (SMD = −0.95; 95% CI: −2.06, 0.15; I²: 98%). Masini and their colleagues also reported similar findings as they reported that Active-break interventions had a significant effect in increasing PA levels, MVPA and step count among primary school children and their meta-analysis demonstrated a statistically significant result for the step count (p < 0.00001, CI 95% −0.71,1.21) (random model I 2 = 0%) [21]. It should be noted that both reviews [21, 25], included five matching primary studies and the methodological quality of most of the included studies in the review of [25], was generally low and the risk of bias was very high. Furthermore, five RCTs in the review conducted by Masini and colleagues were poor quality, and 11 cohort studies were medium quality.

Theory-based interventions.

One review [24], investigated universal interventions (n = 178), 62 interventions were theory based and the duration on average was 44 weeks (Range: 1–410 weeks). 146 studies assessed the PA outcomes as 74 studies used accelerometers, 25 studies used pedometers, 58 used questionnaires and 8 studies used direct observation. 141 included studies in this review evaluated the effectiveness of the intervention on PA outcomes post-intervention, and they recorded at least one significant intervention effect on measured PA, while 48 included studies did not show any significant increase in PA. In terms of long-term effectiveness, nine out of nineteen studies showed at least one significant intervention effect on measured PA, while ten studies did not indicate any intervention effect on the PA. In brief, the review of [24] found a high percentage of effective interventions, some single-feature interventions were found to be effective while no specific feature combination seemed to be associated with better intervention effectiveness. Therefore, theory-based single as well as multi-feature interventions seem to have the potential to improve effectiveness concerning PA, CRF, and sedentary behaviour [24]. It should be noted that the quality of the included studies in this review was unknown since the authors did not assess the risk of bias.

Multi-component interventions.

In the review of [26] most of their interventions (70%) were multi-component interventions and they found that interventions in children resulted in a small positive treatment effect in the intervention group compared to the control group (2.14; 95% CI = 0.77, 3.50). There was no significant effect on sedentary behaviors, energy intake, and fruit and vegetable intake but significant reductions were found between groups in BMI kg/m2 (−0.39; 95% CI = −0.47, −0.30) and BMI z-score (−0.05; 95% CI = −0.08, −0.02) in favour of the intervention. However, the quality of most of the included studies in this review was at low risk of bias.

Physical education lessons.

The last review of this age group [22] was to examine interventions to increase MVPA content in physical education. Their intervention “Born to Move physical activity and fitness intervention alongside a regular PE lesson” found favorable intervention effects on children’s MVPA in all the studies, with a pooled effect of 14.3% higher lesson time in MVPA in the intervention groups, equivalent to around a 9-minute improvement in MVPA per 1 hour of PE lesson time. The range was from a 4% to 30% difference in the MVPA content of PE lessons. Evidence quality was generally high in this review.

Multi-component interventions.

Buru and their colleagues reviewed three types of interventions: physical activity, sedentary behavior and nutrition. PA was used in 11 out of 13 reviewed studies, the shortest intervention was four months and the longest was two years with a follow-up of three years. They found that only two of the included studies reported a significant increase in active transport, in terms of change in PA. Furthermore, only four of the included studies reported a significant decrease in BMI, whereas eight studies did not find any significant changes in BMI. Furthermore, three included studies recorded a significant decrease in body fat and only one study reported a significant decrease in body weight for the intervention group as compared to the control group. Therefore, Buru and their colleagues thought that despite the weak evidence of intervention efficacy for most of the reviewed studies, school-based interventions with multi-component combinations of physical activity, nutrition, and alignment to a theory yielded promising results. The quality assessment of included studies revealed that 11 studies were of medium quality and two studies were of high quality.

In the systematic review that was focused on only adolescent girls [19], most of their interventions were multi-component, four interventions were modified PE lessons and two were educational based, the shortest intervention was six months and the longest was three years. 13 interventions were delivered by the school staff, two were delivered by instructors and two by research team. Ten included studies used accelerometers to measure PA, nine studies used self-report questionnaires and two studies combined self-report and accelerometers. Owen with their colleagues found that school-based interventions provided a small, but significant positive effect on PA levels among adolescent girls (k = 16, g = 0.07, p = 0.05). The quality assessment for included studies revealed that ten studies were classified as having a moderate risk of bias, six studies were weak, three were strong and one had a very strong risk of bias.

Active breaks intervention.

The systematic review conducted by [27], aimed to examine the impact of school-based physical activity interventions of “active breaks” on PA levels and other outcomes such as classroom behaviour, cognitive functions and well-being. They reviewed three studies about physically active lessons and active break interventions. Intervention periods varied from 11 weeks to 7 months. They found that two of the included studies demonstrated a positive effect of active breaks on students’ classroom behavior and quality of life whereas, one study reported a positive effect in the increase in school physical activity levels, and this effect was not found in the overall levels of PA or the reduction of sedentary behavior. The quality assessment revealed that one was good, one was poor and one was fair quality.

Active transport.

Three reviews [29, 32, 34] investigated interventions concerning “active school transport” and “active commuting to and from school”. In reviews of [29, 34], accelerometers were used to measure PA in all included studies. Larouche et al reported that 13 interventions resulted in a statistically significant increase in active school transport whereas eight reported no changes at all, four included studies recorded inconsistent results and five did not record inferential statistics. Campos‐Garzón et al included 14 studies of which 11 were cross-sectional and two longitudinal studies, and their meta-analysis found that the overall active commuting to and from school weighted light physical activity (ACS) was 19.55 min (95% CI: 3.84–35.26; I2  =  99.9%, p < 0.001) and 68.74 min (95% CI: 6.09–131.39; z  =  2.15, p  =  0.030) during the home-school and school-home trips, respectively. For MVPA, the overall ACS weighted MVPA was 8.98 min (95% CI: 5.33–12.62; I2  =  99.95%, p < 0.001) during the home-school trip and 20.07 min (95% CI: 13.62–26.53; I2  =  99.62%, p < 0.001) during the school-home trip. Schönbach et al included nine studies that investigated seven unique interventions and they reported that only one included study reported positive intervention effects on total MVPA (β = 21.6 [CI95: 8.7, 34.6]), MVPA from cycling (β = 23.0 [CI95: 10.7, 35.4]) and MVPA before/after school (β = 12.8 [CI95: 8.5, 17.2]).

It should be noted that most of the included studies in the reviews of [29, 32] were rated as poor quality and had severe limitations in the design and implementation of interventions, therefore, they attributed a low grade for the overall quality of evidence. For the review conducted by [34] most studies had a low risk of bias and medium quality.

Multicomponent interventions.

In two reviews [16, 17] most of their included interventions were concerning diet, education, and PA. The review of [17] was in Latin America and the review of [16] was in the Middle East and Arabic-speaking countries. [17] reviewed 16 interventions most of which targeted diet alone and two focused on PA compared a curriculum of PA programming with a conventional PE class, the duration ranged from four months to two years with a minimum follow-up of five months. They reported that above 60% of the included studies recorded a significant effect on at least one dietary/PA or obesity-related outcome, and five included studies reported a significant effect on physical condition tests and/or PA time. While [16] reviewed 17 interventions most of them were multi-component (lifestyle, diet, education) and few studies focused on PA. The duration ranged from six weeks to three years with a maximum follow-up of one year. They reported that eleven included studies recorded statistically significant improvements in the levels of PA among their participants based largely on self-reported outcomes. They also reported that the studies with a follow-up period greater than three months reported sustained PA levels. It should be noted that most of the included studies (13 out of 16) in the review conducted [17] were weak quality. In the review of [16], 14 out of 17 studies had a low risk of bias.

Single component interventions.

In the review conducted by [28], they aimed to examine the possibility of school-based interventions for promoting PA and PF and preventing obesity. They reviewed 19 studies and most of the interventions were focused on physical activity-related interventions including expanding the duration of PE or altering its content, performing extracurricular physical activities, participating in activities during breaks and lunch breaks, or providing activity breaks in classes other than PE. They recorded that when the BMI variable was examined in studies more focused on PA, the success rate was 72.72% in eight out of 11 studies included and the success rate was found in only two included studies used PA as support. These findings refer to that PA-oriented interventions are more likely to be successful in the BMI variable. Furthermore, when the PA variable was examined, they found that PA levels of school children significantly increased in a proportion of the studies, and this success rate was achieved in studies focused on orientation and training. This result might show the significance of applying physical activity strategies as the focus of the intervention program to increase the levels of PA [28]. It should be noted that 10 included studies were rated as strong quality whereas nine studies were moderate quality.

Educational interventions.

The review and meta-analysis conducted by [30] aimed to evaluate the effects of educational interventions on promoting regular PA. They reviewed 14 studies and 8 of them were performed as a controlled clinical trial. They reported that the overall estimate of the mean difference demonstrated that interventions had a statistically significant effect on weight loss, the intervention group had a weight loss of 1.02 kg (95% CI: 0.22–4.79 kg) compared with the control group and the effectiveness in included studies that used combined intervention for a longer period of time was higher than one-dimensional interventions. The quality assessment revealed that six included studies were high quality, four studies were medium and four were weak quality [30].

Active desks.

The review of [33], investigated the effects of active desks on sedentary behavior, PA, academic achievements, and overall health. They included 23 studies and active desks were in three forms: upright active desk, cycling desk and stability ball. One included study out of 23 found a significant difference in BMI for the interventional group compared to the control group after two years of intervention (−5.24 for BMI percentile) and other studies did not report any change. For sedentary behavior, two included studies noticed that when children used upright active desks spent significantly less time sedentary rather than children in the control group and six included studies reported a significant decrease in sitting time during school hours in the intervention group. Regarding PA, included studies recorded several different outcomes such as light PA, MVPA, step counts, stepping, standing, and walking time. For MVPA, two studies reported contradictory results and one study observed a significant increase in MVPA between pre- and post-intervention. Furthermore, statistically significant increases were reported for standing time in nine included studies. For step counts, one study recorded an increase but without statistical analyses. For stepping time, one study reported an increase in light PA and MVPA with an objective measurement. Regarding academic performance, only two studies that used upright active desks recorded an increase in the intervention group without any change in concentration. The overall quality of the included studies in the review of [33] was low.

Motivational interventions.

The review of [31] examined motivational interventions based on PA as the precursor of psychosocial benefits among children and adolescents. 45 studies were included, and 39 studies presented a quasi-experimental design and between five and twenty weeks were the average durations of the intervention programs. Vaquero-Solís reported that 23 studies out of 45 demonstrated psychological effects, 10 included studies demonstrated psychosocial effects after the intervention and the rest studies reported changes that were not significant. Moreover, the majority of reviewed studies were based on the theoretical models: Achievement Goal Theory and Self-Determination Theory. Therefore, their review demonstrated the significance of motivational processes for the implementation of PA and sport as a precursor of psychosocial changes highlighting the significance of strategies and the duration of interventions/programmes—ie the longer interventions also have a longer lasting impact on behaviour to maintain significant changes over time. The majority of included studies in review of [31] were rated as high quality with few being medium quality.

Impact on MVPA and fitness.

The review of [37], investigated intervention effectiveness to increase MVPA and improve fitness. There were 89 included studies in the review representing 66,752 individuals. They reviewed 40 multi-component interventions, 19 school time PA, 15 enhanced PE, and 14 before and after school programs. The duration of interventions varied greatly from a minimum of 12 weeks to 6 years, with 10 studies reporting intervention periods of 3 years or longer. Their review showed that interventions based in schools may result in little to no increase in time engaged in MVPA (mean difference 0.73 minutes/d, 95% confidence interval 0.16 to 1.30, little to no decrease in sedentary time (MD -3.78 minutes/d, 95% CI -7.80 to 0.24, may improve PF recorded as maximal oxygen uptake (VO2max) (MD 1.19 mL/kg/min, 95% CI 0.57 to 1.82 and may result in a minimal decrease in BMI z-scores (MD -0.06, 95% CI -0.09 to -0.02. The overall quality of the included studies in the review of [37] was as follows: 33 studies were moderate quality, and 56 studies were low quality.

Impact on HRQoL.

The meta-analysis conducted by [35], aimed to assess the effects of PA interventions on several domains of health-related quality of life (HRQoL) and to examine the effectiveness of interventions on the same domains. They reviewed 17 different interventions and most of them were adding extra (PE) lessons to the regular school curriculum with a few of them being short active breaks. Their meta-analysis indicated that pooled effect size (95% CI) estimates for the effect of PA on HRQoL were as follows: 0.179 (0.045, 0.002) for total HRQoL score, 0.192 (0.077, 0.306) for physical well-being, 0.158 (0.080, 0.237) for psychological well-being. In brief, their results conclude that physical exercise improved overall HRQoL and several HRQoL domains, such as physical well-being, psychological well-being, autonomy and parent relation, and social support and peers. However, their findings indicate no positive effect of the exercise programs on the school environment domain. The risk of bias for the included studies in the review of [35] showed that six out of 17 were at high risk of bias, four studies were medium, and seven studies were at low risk of bias.