Related Experiment Video
Updated: May 10, 2026
Physical Activity Measurement in Children Accepting Table Tennis Training
Published on: July 27, 2022
Sleep, physical activity and BMI in six to ten-year-old children measured by accelerometry: a cross-sectional study
Mirjam Ekstedt1, Gisela Nyberg, Michael Ingre
1Department of Clinical Science, Intervention and Technology, Division of Pediatrics, Karolinska Institutet, Stockholm, Sweden. Mirjam.ekstedt@sth.kth.se
Insights
Short sleep duration is linked to higher Body Mass Index (BMI) in children aged 6-10. Consistent bedtimes and moderate-to-vigorous physical activity may improve sleep duration and quality in preadolescents.
Area of Science:
- Pediatric Health
- Sleep Science
- Exercise Physiology
Background:
- Understanding the interplay between sleep, physical activity, and Body Mass Index (BMI) is crucial for pre-adolescent health.
- Previous research indicates potential links, but objective measures in this age group require further investigation.
Purpose of the Study:
- To examine the relationship between objective sleep and physical activity measures and BMI in Swedish pre-adolescents.
- To describe the daily associations between physical activity and sleep quality.
- To analyze weekday and weekend sleep patterns.
Main Methods:
- Cross-sectional study of 1,231 children aged 6-10 years in Stockholm.
- Objective measurement of sleep and physical activity using accelerometry over seven consecutive days.
- Assessment of total sleep time, sleep efficiency, physical activity intensity (sedentary, light, moderate-to-vigorous), and BMI standard deviation score (BMIsds).
Main Results:
- Total sleep time decreased with age and was shorter in boys than girls.
- Weekend sleep duration was shorter due to later bedtimes and consistent wake times.
- Moderate-to-vigorous physical activity was associated with improved sleep efficiency the following night.
- High levels of moderate-to-vigorous physical activity were linked to more interrupted sleep.
- A negative association was found between BMIsds and sleep duration.
Conclusions:
- Short sleep duration in children aged 6-10 is associated with higher BMI.
- Consistent daily bedtimes are important for promoting adequate sleep duration in pre-adolescents.
- Intensive physical activity during the day may contribute to better sleep quality.
Background:
The aim of this study is to describe the relationship between objective measures of sleep, physical activity and BMI in Swedish pre-adolescents. The day-to-day association between physical activity and sleep quality as well as week-day and weekend pattern of sleep is also described.
Method:
We conducted a cross sectional study consisted of a cohort of 1.231 children aged six to ten years within the Stockholm county area. Sleep and physical activity were measured by accelerometry during seven consecutive days. Outcome measures are total sleep time, sleep efficiency, sleep start and sleep end; physical activity intensity divided into: sedentary (<1.5 METS), light (1.5 to 3 METS) and moderate-to-vigorous (> 3 METS); and Body Mass Index standard deviations score, BMIsds.
Results:
Total sleep time decreased with increasing age, and was shorter in boys than girls on both weekdays and weekends. Late bedtime but consistent wake-up time during weekends made total sleep time shorter on weekends than on weekdays. Day-to-day within-subject analysis revealed that moderate-to-vigorous intense physical activity promoted an increased sleep efficiency the following night (CI < 0.001 to 0.047), while total sleep time was not affected (CI -0.003 to 0.043). Neither sleep duration (CI -0.024 to 0.022) nor sleep efficiency (CI -0.019 to 0.028) affected mean physical activity level the subsequent day. The between-subject analysis indicates that the sleep of children characterized by high moderate-to-vigorous physical activity during the day was frequently interrupted (SE = -.23, P < .01). A negative association between BMIsds and sleep duration was found (-.10, p < .01).
Conclusions:
Short sleep duration was associated with high BMI in six to ten year old children. This study underscores the importance of consistent bedtimes throughout the week for promoting sleep duration in preadolescents. Furthermore, this study suggests that a large proportion of intensive physical activity during the day might promote good sleep quality.
