Longitudinal study of physical activity and sedentary behavior in children

Area of Science:

• Pediatric Health
• Behavioral Science
• Public Health

Background:

• Childhood physical activity is crucial for long-term health.
• Previous research suggests a decline in physical activity during childhood, but objective data is limited.
• Understanding these changes before adolescence is vital for intervention strategies.

Purpose of the Study:

• To objectively measure 2-year changes in physical activity and sedentary behavior in English children.
• To explore the timing, nature, and extent of these changes before adolescence.
• To identify factors associated with changes in physical activity and sedentary behavior.

Main Methods:

• Longitudinal study of 405 children (aged 7 years) over 24 months.
• Objective measurement of physical activity and sedentary behavior using Actigraph GT1M accelerometers.
• Analysis included quantification of changes in physical activity volume, moderate-to-vigorous physical activity (MVPA), and sedentary behavior, with linear regression and correlation for associated factors.

Main Results:

• Mean daily physical activity volume declined by 83 counts per minute (cpm).
• Moderate-to-vigorous physical activity (MVPA) declined by 0.3%, while sedentary behavior increased by 3.1%.
• Declines in MVPA and increases in sedentary behavior were greater in girls and children with higher BMI z scores. Physical activity and sedentary behavior showed moderate tracking.

Conclusions:

• This study provides new evidence of low and declining physical activity levels, including MVPA, before adolescence.
• Sedentary behavior significantly increased during this period.
• Findings highlight the need for interventions to promote physical activity in pre-adolescent children, particularly girls.