Positive effects on bone mineralisation and muscular fitness after 10 months of intense school-based physical training for children aged 8-10 years: the FIT FIRST randomised controlled trial.
OBJECTIVE
We investigated whether musculoskeletal fitness of school children aged 8-10 years was affected by frequent intense PE sessions.


METHODS
295 Danish school children aged 8-10 years were cluster randomised to a small-sided ball game group (SSG) (n=96, four schools, five classes), a circuit strength training group (CST) (n=83, four schools, four classes) or a control group (CON, n=116, two schools, five classes).


METHODS
SSG or CST was performed 3×40 min/week over 10 months. Whole-body dual-energy X-ray absorptiometry (DXA) scans were used to determine areal bone mineral density (aBMD), bone mineral content (BMC) and lean body mass (LBM). Flamingo balance, standing long jump and 20-m sprint tests were used to determine muscular fitness.


RESULTS
Analysis of baseline-to-10 months change scores showed between-group differences in favour of the interventions in whole-body aBMD (SSG vs CON: 8 mg/cm2, 95% CI 3 to 13; CST vs CON: 7 mg/cm2, 95% CI 2 to 13, p<0.05) and leg BMC (SSG vs CON: 11 g, 95% CI 4 to 18; CST vs CON: 11 g, 95% CI 3 to 18, p<0.05). SSG had higher change scores in leg aBMD compared with CON and CST (SSG vs CON: 19 mg/cm2, 95% CI 11 to 39, p<0.05; SSG vs CST: 12 mg/cm2, 95% CI 3 to 21, p<0.05), and CST had higher change scores in whole-body BMC compared with CON (CST vs CON: 25 g, 95% CI 10 to 39, p<0.05). Both training types resulted in higher change scores in postural balance (SSG vs CON: 2.4 fewer falls/min, 95% CI 0.3 to 4.5, CST vs CON: 3.6 fewer falls/min, 95% CI 1.3 to 5.9, p<0.05) and jump length (SSG vs CON: 10%, 95% CI 5 to 16%; CST vs CON: 9%, 95% CI 3 to 15%, p<0.05). No between-group differences were observed for sprint performance or LBM (p>0.05).


CONCLUSIONS
In conclusion, 3×40 min/week with SSG or CST over a full school year improves bone mineralisation and several aspects of muscular fitness of children aged 8-10 years, suggesting that well-organised intense physical education classes can contribute positively to develop musculoskeletal health in young children.


BACKGROUND
NCT02000492, post results.
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.
Malte Nejst
MN
Larsen
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.|Frederikssund Municipality, Frederikssund, Denmark.
Claus Malta
CM
Nielsen
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.
Eva Wulff
EW
Helge
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.
Mads
M
Madsen
Frederikssund Municipality, Frederikssund, Denmark.
Vibeke
V
Manniche
Team Danmark, Brøndby, Denmark.
Lone
L
Hansen
Department of Cardiology, Herlev-Gentofte University Hospital, Hellerup, Denmark.
Peter Riis
PR
Hansen
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.
Jens
J
Bangsbo
Department of Nutrition, Exercise and Sports, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark.|Department of Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
Peter
http://orcid.org/0000-0001-9843-7320
P
Krustrup
D015502:Absorptiometry, Photon; D000886:Anthropometry; D015519:Bone Density; D002648:Child; D003718:Denmark; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D010806:Physical Education and Training; D010809:Physical Fitness; D004856:Postural Balance
Body composition; Bone mineral density; Children; Muscle; Training load