A 3-year school-based exercise intervention improves muscle strength - a prospective controlled population-based...

Area of Science:

• Pediatric exercise science
• Childhood physical activity interventions
• Musculoskeletal health in youth

Background:

• Intense physical activity (PA) is known to enhance muscle strength in children.
• The impact of moderately intense PA on muscle strength in a general pediatric population remains less understood.

Purpose of the Study:

• To investigate the effects of a 3-year moderately intense PA intervention on muscle strength in school-aged children.
• To compare changes in knee flexor peak torque between intervention and control groups.

Main Methods:

• A 3-year intervention involving 4 schools, with one group increasing PA to 40 minutes/school day, while control schools maintained 60 minutes/week.
• Muscle strength measured via isokinetic Peak Torque (PT) of knee flexors at 60°/second and 180°/second in 6-9 year olds.
• Annual changes in muscle strength calculated for 47 girls and 76 boys in the intervention group, and 46 girls and 54 boys in the control group.

Main Results:

• Girls in the intervention group showed a 1.0 Nm greater annual gain in knee flexor PT at 60°/second compared to controls.
• Boys in the intervention group demonstrated a 1.9 Nm greater annual gain at 60°/second and a 1.5 Nm greater annual gain at 180°/second than controls.
• These gains indicate a significant positive effect of the intervention on muscle strength.

Conclusions:

• A 3-year school-based moderately intense PA program effectively enhances muscle strength in both boys and girls.
• Integrating PA into the school curriculum is a viable strategy for improving children's physical fitness.
• The findings support the implementation of such programs to foster long-term musculoskeletal health in children.