Effects of an 8-year childhood physical activity intervention on musculoskeletal gains and fracture risk

The Benefits to Bone Health in Children and Pre-School Children with Additional Exercise Interventions: A Systematic Review and Meta-Analysis

OBJECTIVE

Determine if exercise interventions, beyond what is already provided to children and preschool children, improve bone health and reduce fracture incidence.

DESIGN

Systematic review and meta-analysis reported using the PRISMA guidelines. Certainty of evidence was assessed using GRADE recommendations.

DATA SOURCES

Five electronic databases were searched for records: PUBMED; CINAHL; CENTRAL; SPORTDiscus; Web of Science.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised, quasi-randomised and non-randomised controlled trials (including cluster-randomised) assessing the impact of additional exercise interventions (e.g., increased physical education classes or specific jumping programs) on bone health in children (6-12 years) and pre-school children (2-5 years) without dietary intervention.

RESULTS

Thirty-one records representing 16 distinct clinical trials were included. Dual-energy X-ray Absorptiometry (DXA) and/or peripheral Quantitative Computed Tomography (pQCT) were used to quantify bone health. Increased femoral neck bone mineral content in children with additional exercise interventions (n = 790, SMD = 0.55, 95% CI = 0.01 to 1.09) was reported, however this was not significant following sensitivity analysis. Other DXA and pQCT measures, as well as fracture incidence, did not appear to significantly differ over time between intervention and control groups. No studies reported adverse events. Studies failed to report all domains within the TIDieR checklist. All studies were at high risk of bias using the Cochrane RoB Tool 2.0. The certainty of the evidence was very low.

CONCLUSIONS

The addition of exercise interventions, beyond what is provided to children, does not appear to improve DXA and pQCT measures of bone health. The effect of additional exercise interventions on bone health in pre-school children is largely unknown. Future trials should ensure adherence is clearly reported and controlled for within analysis as well as including reports of adverse events (e.g., apophysitis) that occur due to increased exercise interventions.

The Effects of a Physical Education Intervention Program on the Bone Properties of Second- and Third-Grade Pupils: A Cluster Randomized Controlled Trial

BACKGROUND

Many young children do not participate in sufficient physical activity for promoting optimal bone growth. The objective of this study was to investigate the effect of young children who participated in a school-based intervention program on bone properties. The program included structured physical activity, with a focus on the application of mechanical loads on the upper and lower limbs.

METHODS

A cluster randomized controlled trial was conducted, in which classes were randomly assigned to the intervention or control groups. A total of 295 (50.17% girls) children from the second and third grades from 12 classes in Israel were randomly allocated to an intervention consisting of three 10-minute weekly medium- to high-intensity activities throughout one academic year or to a treatment as usual control group. Bone properties were measured at the distal radius and tibia shaft using speed of sound, before and after the intervention.

RESULTS

Distal radius properties improved significantly for both boys and girls in the intervention group (boys: meanpre = 3769.95, meanpost = 3875.08, Δ = 2.80%; girls: meanpre = 3766.27, meanpost = 3890.83, Δ = 3.30%; d = 1.03); whereas, tibia shaft properties only significantly improved for boys (meanpre = 3663.98, meanpost = 3732.75, Δ = 1.90%; d = 1).

CONCLUSIONS

These findings indicate that distal radius properties of children can be positively affected by a short, easy to implement intervention program that does not require special resources.

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.

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

Daily school physical activity (PA) improves musculoskeletal traits. This study evaluates whether the benefits remain 4 years after the intervention. We followed 45 boys and 36 girls who had had 40 min PA/school day during the nine compulsory school years and 21 boys and 22 girls who had had 60 min PA/school week (reference), with measurements at baseline and 4 years after the program terminated. Bone mineral content (BMC; g) and bone mineral density (BMD; g/cm²) were measured by dual-energy X-ray absorptiometry and knee flexion peak torque relative to total body weight (PT_flexTBW) at a speed of 180 degrees/second with a computerized dynamometer. Group differences are presented as mean differences (adjusted for sex and duration of follow-up period) with 95% confidence intervals. The total gain bone mass [mean difference in spine BMC +32.0 g (14.6, 49.4) and in arms BMD of +0.06 g/cm² (0.02, 0.09)] and gain in muscle strength [mean difference in PT_flex180TBW +12.1 (2.0, 22.2)] were greater in the intervention than in the control group. There are still 4 years after the intervention indications of benefits in both bone mass and muscle strength gain. Daily school PA may counteract low bone mass and inferior muscle strength in adult life. ClinicalTrials.gov.NCT000633828 retrospectively registered 2008-11-03.

Levels of physical activity and barriers to sport participation in young people with gender dysphoria

OBJECTIVES

To determine the levels of physical activity (PA) in young people with gender dysphoria (GD) and help identify factors which deter participation.

METHODS

Fifty-six young people who attended paediatric endocrinology because of GD, June to October 2019, and were on treatment with gonadotrophin-releasing hormone (GnRH) analogue were approached to participate in a survey.

RESULTS

A total of 55 young people (98%) responded to the survey. Thirty-eight (69%) participated in PA for >1 h/week. Thirty-two (58%) reported high motivation level for exercise. Those had median age of 15.9 years (10.7, 18.7) at the time of survey, and 13.6 years (9.7, 17.6) at start of GnRH analogue compared to 16.7 years (13.9, 18.5) (p, 0.047) and 15.4 years (11.2, 18.0) (p, 0.009) of the 23 (42%) who reported low motivation. Forty-one (74.5%) reported barriers when accessing PA, such as not being as good as others (75%), revealing sports clothing (73%) and not satisfied with body image (47%). Those were older (16.4 years [10.9, 18.7] vs. 14.7 years [10.7, 18.4] [p, 0.011]) at the time of survey and at start of GnRH analogue (14.9 years [9.7, 18.0] vs. 12.5 years [10.6, 15.2] [p, 0.0001]) than those 14 (25.5%) who reported facing no barriers. Twelve (85.7%) of those reporting no barriers stated high motivation levels compared to 20 (48.8%) of those reporting barriers (p, 0.026).

CONCLUSIONS

Strategies aimed at improving participation are twofold: first to improve motivation, especially in post-pubertal young people, and secondly to achieve societal change to help eliminate barriers.

The association between physical activity and vertebral dimension change in early adulthood - The Northern Finland Birth Cohort 1986 study

Small vertebral size is a well-known risk factor for vertebral fractures. To help understanding the factors behind vertebral size, we aimed to investigate whether physical activity and participation in high-impact exercise are associated with the growth rate of the vertebral cross-sectional area (CSA) among young adults. To conduct our study, we utilized the Northern Finland Birth Cohort 1986 as our study population (n = 375). Questionnaire data about physical activity was obtained at 16, 18 and 19 years of age and lumbar magnetic resonance imaging scans at two timepoints, 20 and 30 years of age. We used generalized estimating equation (GEE) models to conduct the analyses. We did not find any statistically significant associations between vertebral CSA, physical activity, and high-impact exercise in our study sample. We conclude that neither physical activity nor high-impact sports seem to influence the change in vertebral CSA among young adults.

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Physical activity does not influence the growth rate of the vertebral body.

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High-impact sports are not associated with the change in vertebral CSA among adults.

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The study was conducted using longitudinal MRI data.

Play During Growth: the Effect of Sports on Bone Adaptation

PURPOSE OF REVIEW

The development of exercise interventions for bone health requires an understanding of normative growth trends. Here, we summarize changes in bone during growth and the effect of participating in sports on structural and compositional measures in different bones in males and females.

RECENT FINDINGS

Growing females and males have similar normalized density and bone area fraction until age 16, after which males continue increasing at a faster rate than females. All metrics for both sexes tend to plateau or decline in the early 20s. Areal BMD measures indicate significant heterogeneity in adaptation to sport between regions of the body. High-resolution CT data indicate changes in structure are more readily apparent than changes in density. While adaptation to sport is spatially heterogeneous, participation in weight-bearing activities that involve dynamic muscle contractions tends to result in increased bone adaptation.

Improving musculoskeletal health for children and young people - A 'call to action'

This chapter describes the musculoskeletal (MSK) context in children and young people as an important contributor to the global non-communicable disease burden. Through selected MSK conditions, we describe the impact on patients, families and communities and highlight the challenges that need to be addressed. We focus on opportunities for better working together and describe exemplar initiatives to raise awareness, workforce capacity building, models of care and research agendas to have a greater global context.

Exercise and Peak Bone Mass

PURPOSE OF REVIEW

The main goal of this narrative review is to assess whether physical activity (PA) influences peak bone mass and fracture risk.

RECENT FINDINGS

Several randomized controlled trials (RCT) show that short-term PA intervention programs in childhood improve the accrual of bone mineral. There are now also long-term controlled PA intervention studies demonstrating that both boys and girls with daily school PA through puberty gain higher bone mineral content (BMC) and bone mineral density (BMD) and greater bone size than boys and girls with school PA 1-2 times/week. These benefits seem to be followed by a gradual reduction in expected fracture rates, so that in children with daily school PA, the incidence rate ratio (IRR) after 8 years is less than half that expected by age. Daily school PA from before to after puberty is associated with beneficial gains in bone traits and gradually lower relative fracture risk.

Daily School Physical Activity from Before to After Puberty Improves Bone Mass and a Musculoskeletal Composite Risk Score for Fracture

This 7.5-year prospective controlled exercise intervention study assessed if daily school physical activity (PA), from before to after puberty, improved musculoskeletal traits. There were 63 boys and 34 girls in the intervention group (40 min PA/day), and 26 boys and 17 girls in the control group (60 min PA/week). We measured musculoskeletal traits at the start and end of the study. The overall musculoskeletal effect of PA was also estimated by a composite score (mean Z-score of the lumbar spine bone mineral content (BMC), bone area (BA), total body lean mass (TBLM), calcaneal ultrasound (speed of sound (SOS)), and muscle strength (knee flexion peak torque)). We used analyses of covariance (ANCOVA) for group comparisons. Compared to the gender-matched control group, intervention boys reached higher gains in BMC, BA, muscle strength, as well as in the composite score, and intervention girls higher gains in BMC, BA, SOS, as well as in the composite score (all p < 0.05, respectively). Our small sample study indicates that a daily school-based PA intervention program from Tanner stage 1 to 5 in both sexes is associated with greater bone mineral accrual, greater gain in bone size, and a greater gain in a musculoskeletal composite score for fractures.

Long-term effects of daily physical education throughout compulsory school on duration of physical activity in young adulthood: an 11-year prospective controlled study

Objectives

We examined whether daily physical activity (PA) during compulsory school encourages children to be more physically active during the intervention and 4 years after termination of the programme.

Methods

This prospective controlled intervention study followed the same 124 children (81 children in an intervention group and 43 controls) aged 7.7±0.6 (mean±SD) during a 7-year PA intervention and 4 years after the intervention when the children were 18.7±0.3 years old. The intervention included daily school physical education (PE) (200 min/week), whereas the controls continued with the Swedish standard of 60 min/week. Using a questionnaire, we gathered data about total PA, leisure time PA and sedentary activities (SA). Group comparisons are adjusted for age and gender, and data are provided as means with 95% CIs.

Results

At baseline, we found similar duration of PA and SA between groups. After a mean of 7 years with intervention, the intervention group was more physically active than the controls (+4.5 (2.9 to 6.0) hours/week), whereas SA was similar (+0.6 (−2.5 to 3.9) hours/week). Four years beyond the intervention, the intervention group was still more physically active than the controls (2.7 (0.8 to 4.7) hours/week), and SA was still similar (−3.9 (−9.7 to 1.7) hours/week).

Conclusions

Intervention with daily school PE throughout compulsory school is associated with higher duration of PA not only during the intervention but also 4 years after termination of the programme.

A comparative study found that a seven-year school-based exercise programme increased physical activity levels in both sexes

AIM

This study assessed whether a Swedish school-based exercise intervention programme could increase total physical activity.

METHODS

We followed up 228 children who started school in 1998-2000 seven years later, when they had reached a mean age of 14.8. The 152 children (59% boys) at the intervention school did 200 minutes of physical education per week during that period, and the 76 children (50% boys) in the three control schools did the standard 60 minutes. Questionnaires assessed the durations of total and leisure-time physical activity and screen-time activity at baseline and after five and seven years.

RESULTS

Physical activity and screen-time activity were similar between the two groups before the study started. The intervention group then achieved higher durations of total physical activity than the controls (p < 0.001) and these levels remained in the sex-specific evaluations. There were no differences between the groups in the durations of leisure-time activity (p 0.08-0.77) or screen-time activity (p 0.31-0.91).

CONCLUSION

A school-based exercise intervention programme increased the total duration of physical activity in both sexes without any compensatory increase in screen-time activity. The findings contradict the activity-stat theory, which stated that the duration of physical activity in children is constant.

Low physical activity is related to clustering of risk factors for fracture-a 2-year prospective study in children

The study investigates the effect of physical activity (PA) on a composite score for fracture risk in pre-pubertal children. Low PA in children is related to the composite score for fracture risk and the pre-pubertal years seem to be a period when PA positively affects the score.

INTRODUCTION

This study evaluates if PA in children is related to clustering of risk factors for fracture. Research questions are the following: (i) What is the effect of physical activity (PA) on single traits and a composite score for fracture risk? (ii) Could this score be used to identify the level of PA needed to reach beneficial effects?

METHODS

This prospective population-based study included 269 children, aged 7-9 years at baseline while 246 attended the 2-year follow-up. We estimated duration of PA by questionnaires and measured traits that independently predict fractures. We then calculated gender specific Z-scores for each variable. The mean Z-score of all traits was used as a composite score for fracture risk. We tested correlation between duration of PA, each trait, and the composite score and group differences between children in different quartiles of PA.

RESULTS

At baseline, we found no correlation between duration of PA and any of the traits or the composite score. At follow-up, we found a correlation between PA and the composite score. Physical activity had an effect on composite score, and children in the lowest quartiles of PA had unbeneficial composite score compared to children in the other quartiles.

CONCLUSION

Low PA in children is related to clustering of risk factors for fracture, and the pre-pubertal years seem to be a period when PA positively affects the composite score.

The effects of introducing Tabata interval training and stability exercises to school children as a school-based intervention program

Background Physical activities during leisure time as well as school hours have changed over the past few years, with adolescents being less physically active and adopting a sedentary lifestyle. Objective The overall objective of this mixed-methods study was to evaluate the feasibility of introducing a 4-min Tabata interval training into a lower secondary school context. A further aim was to evaluate the possible effects on: coordination, balance, and strength. Methods The study was conducted as an intervention study with a mixed-method approach. Forty-three children, aged 7-9 years, participated in the intervention group. Additionally, 13 children were recruited as a control group. The intervention itself was delivered by the teachers and was performed for 4-min every day in a classroom setting. All participants performed physical tests before and after the intervention period to evaluate the Tabata training. After the completion of the 6-week Tabata interval training, the four teachers were interviewed. Results The push-ups (p = 0.004), kneeling push-ups (p = 0.03), and standing long jump (p = 0.01) improved in the intervention group after 6 weeks. No differences were observed between the genders. The teachers experienced that it worked well to integrate the Tabata interval training in the classroom setting. Conclusion After 6 weeks, a school-based Tabata intervention program improved physical performance. The teachers saw no obstacles in including the Tabata intervention program in a classroom setting and pointed out several positive aspects such as an increased energy level and development in the children's movement patterns.