Bidirectional Associations between Objective Physical Activity and Sleep Patterns in Spanish School Children

Area of Science:

• Pediatric Health
• Sleep Science
• Exercise Physiology

Background:

• Physical activity (PA) and sleep are crucial for child health.
• The bidirectional relationship between PA and sleep in children lacks clarity using objective data.
• Understanding these links is vital for developing effective health interventions.

Purpose of the Study:

• To assess children's physical activity and sleep patterns against recommendations.
• To investigate the bidirectional associations between physical activity and sleep in Spanish children.
• To explore sex-based differences in these relationships.

Main Methods:

• Objective measurement of physical activity (light PA, MVPA) and sleep (duration, latency, efficiency) using accelerometers and sleep logs over seven days.
• Inclusion of 470 Spanish children (average age 8.4 years, 51.9% boys).
• Analysis using linear mixed models to account for individual, sex, school, and day variations.

Main Results:

• Children generally did not meet recommended daily sleep durations.
• Increased daily light PA and moderate-to-vigorous PA (MVPA) correlated with reduced sleep duration but improved sleep efficiency.
• Sleep duration and efficiency showed mixed associations with the following day's light PA, with light PA impacting sleep efficiency positively.
• Light PA was linked to decreased sleep duration in both sexes, but more so in boys, and improved sleep efficiency in both, with girls showing higher efficiency.

Conclusions:

• Objective data reveals children's insufficient sleep duration and complex PA-sleep interplays.
• Daily physical activity influences sleep quality and duration, with varying effects on subsequent sleep.
• Further research with larger, representative samples is needed to confirm these bidirectional PA-sleep associations in children.