Temporal Associations of Physical Activity Volume, Intensity, and Timing With Sleep in Preschool-Aged Children

Area of Science:

• Pediatric sleep science
• Physical activity research
• Child development

Background:

• Understanding the interplay between physical activity and sleep is crucial for child health.
• Preschoolers' sleep and activity patterns are foundational for long-term well-being.
• Limited research exists on the bidirectional temporal associations between physical activity metrics and sleep in young children.

Purpose of the Study:

• To investigate the temporal relationships between accelerometer-derived physical activity metrics (volume, intensity, timing) and sleep in preschool-aged children.
• To examine associations between waketime physical activity and subsequent sleep, and between sleep and subsequent physical activity.
• To explore these associations at both within-person and between-person levels.

Main Methods:

• Utilized baseline data from a randomized controlled trial involving 93 preschool children (aged 3-5.9 years).
• Employed the GGIR R package to derive daily measures of physical activity (acceleration, intensity gradient, M10 start) and sleep (duration, efficiency, midpoint).
• Applied linear mixed models to analyze temporal associations between physical activity and sleep metrics.

Main Results:

• Higher daytime physical activity intensity gradient predicted lower subsequent sleep efficiency.
• At the between-person level, longer sleep duration, later sleep midpoint, and lower sleep efficiency were associated with later physical activity timing the following day.
• Bidirectional associations between physical activity timing and sleep midpoint were observed at both within- and between-person levels.

Conclusions:

• The timing of physical activity and sleep midpoint demonstrate consistent bidirectional relationships in preschoolers.
• Findings suggest that incorporating appropriately timed, lower-intensity physical activities into daily routines may be beneficial for improving sleep in young children.
• Interventions aimed at optimizing sleep in preschoolers could consider both sleep scheduling and physical activity timing.