Musculoskeletal Benefits from a Physical Activity Program in Primary School are Retained 4 Years after the Program is Terminated

Mobile application interventions to increase physical activity and their effect on kinanthropometrics, body composition and fitness variables in adolescent aged 12-16 years old: An umbrella review

BACKGROUND

The aims of the present umbrella review were (a) to summarize the available evidence on the effectiveness of mobile applications aimed at increasing physical activity; (b) to analyse the effect of an increase in physical activity on kinanthropometric variables, body composition and physical fitness of adolescents aged 12-16 years old; and (c) to determine the strengths and limitations of the interventions carried out with adolescents aged 12-16 years old through the use of mobile applications, to provide recommendations for future research.

METHODS

The most relevant inclusion criteria were (a) adolescents aged 12-16 years old; (b) interventions carried out only with mobile apps; (c) pre-post measurements; (d) participants without illnesses or injuries; and (e) interventions lasting more than 8 weeks. The databases used to identify the systematic reviews were the Web of Science, Google Scholar, PubMed and Scopus. Two reviewers independently used the AMSTAR-2 scale to measure the methodological quality of the included reviews and also carried out an analysis of external validity, with a third reviewer participating in the cases in which consensus was not reached.

RESULTS

A total of 12 systematic reviews were included (these included a total of 273 articles that used electronic devices, of which 22 studies exclusively used mobile applications with adolescents aged 12-16). Regarding physical activity and its effect on body composition, kinanthropometric variables and physical fitness, no significant differences were found for any of the variables analysed, and the results were not sufficiently consistent to determine the influence of these interventions.

CONCLUSIONS

It is important to highlight that the scientific research conducted so far showed that mobile applications were not effective in increasing physical activity and changing the kinanthropometric variables, body composition or physical fitness of adolescents. Thus, future research with stronger methodological rigour and larger samples is needed to provide stronger evidence.

The long-term effects of primary school-based obesity prevention interventions in children: A systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis investigate the long-term effects of primary school-based obesity prevention interventions on body-mass index (and z-scores), waist circumference (and z-scores) and weight status.

METHODS

Four databases were searched for studies from date of inception until June 8th, 2021. We included randomized controlled trials (RCT) and non-RCTs investigating effects ≥12 months post-intervention of primary school-based interventions with intervention duration ≥6 months and containing a diet and/or physical activity component on outcomes of interest. Articles were assessed on risk of bias and methodological quality by RoB2 and ROBINS-I. Meta-analysis was performed and results were narratively summarized. Evidence quality was assessed with GRADE.

RESULTS

Nineteen studies were included, 9 were pooled in a meta-analysis. No long-term effects were found on body-mass index (+0.06 kg/m² ; CI95% = -0.38, 0.50; I²  = 66%), body-mass index z-scores (-0.08; CI95% = -0.20, 0.04; I²  = 36%), and waist circumference (+0.57 cm; CI95% = -0.62, 1.75; I²  = 13%). Non-pooled studies reported mixed findings regarding long-term effects on body-mass index, body-mass index z-scores and weight status, and no effects on waist circumference and waist circumference z-scores. Evidence certainty was moderate to very low.

DISCUSSION

No clear evidence regarding long-term effects of primary school-based interventions on obesity-related outcomes was found. Recommendations for further research and policy are discussed. Prospero registration ID: CRD42021240446.

Physical Activity in Late Prepuberty and Early Puberty Is Associated With High Bone Formation and Low Bone Resorption

Background

Physical activity (PA) increases bone mass, especially in late prepuberty and early puberty, but it remains unclear if and how PA affects both bone formation and bone resorption.

Materials and Methods

We included 191 boys and 158 girls aged 7.7 ± 0.6 (mean ± SD) in a population-based PA intervention study. The intervention group (123 boys and 94 girls) received daily physical education (PE) in school (40 min/day; 200 min/week) from study start and during the nine compulsory school years in Sweden. The controls (68 boys and 64 girls) received the national standard of 1–2 classes PE/week (60 min/week). During the intervention, blood samples were collected at ages 9.9 ± 0.6 (n = 172; all in Tanner stages 1–2) and 14.8 ± 0.8 (n = 146; all in Tanner stages 3–5) and after termination of the intervention at age 18.8 ± 0.3 (n = 93; all in Tanner stage 5) and 23.5 ± 0.7 (n = 152). In serum, we analyzed bone formation markers [bone-specific alkaline phosphatase (bALP), osteocalcin (OC), and N-terminal propeptide of collagen type 1 (PINP)] and bone resorption markers [C-terminal telopeptide cross links (CTX) and tartrate-resistant acid phosphatase (TRAcP 5b)]. Linear regression was used to compare age and sex-adjusted mean differences between intervention children and controls in these markers.

Results

Two years after the intervention was initiated (at Tanner stages 1–2), we found higher serum levels of bALP and OC, and lower serum levels of TRAcP 5b in the intervention compared with the control group. The mean difference (95% CI) was for bALP: 13.7 (2.1, 25.3) μg/L, OC: 9.1 (0.1, 18.1) μg/L, and TRAcP 5b: −2.3 (−3.9, −0.7) U/L. At Tanner stages 3–5 and after the intervention was terminated, bone turnover markers were similar in the intervention and the control children.

Conclusion

Daily school PA in the late prepubertal and early pubertal periods is associated with higher bone formation and lower bone resorption than school PA 1–2 times/week. In late pubertal and postpubertal periods, bone formation and resorption were similar. Termination of the intervention is not associated with adverse bone turnover, indicating that PA-induced bone mass benefits gained during growth may remain in adulthood.

Physical Activity at Growth Induces Bone Mass Benefits Into Adulthood – A Fifteen‐Year Prospective Controlled Study

Daily school physical activity (PA) improves musculoskeletal traits. Whether or not benefits remain in adulthood is debated. We included in this study 131 children that took part in an intervention with 40 minutes of PA per school day (200 minutes per week) from age 6 to 9 years (grade one) to age 14 to 16 years (grade nine), whereas 78 children continued with national recommended school physical education of 60 minutes per week. Measurements were done with dual‐energy X‐ray absorptiometry (bone mineral content [BMC], bone mineral density [BMD], and bone area), and a computerized knee dynamometer (peak torque muscle strength) at study start, at the end of the intervention, and 7 years after the intervention. Group differences from study start and end of the intervention to 7 years thereafter were estimated by analyses of covariance (adjusted for sex and follow‐up time). Musculoskeletal gains from study start to 7 years after termination of the intervention were higher in the intervention group (total body less head BMC +182.5 g [95% confidence interval {CI}, 55.1–309.9] and BMD +0.03 g/cm² [95% CI, 0.003–0.05], femoral neck area + 0.2 cm² [95% CI, 0.1–0.4], and knee flexion peak torque muscle strength at 60 degrees per second +9.2 Nm [95% CI, 2.9–15.5]). There was no attenuation during the 7 years that followed termination of the intervention (all group comparisons p > 0.05). Benefits in musculoskeletal gains remain 7 years after termination of a daily school‐based PA program, without attenuation after termination of the program. Daily school PA may counteract low bone mass and inferior muscle strength in adulthood. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.