Physical Activity, Sedentary Behaviour, and Sleep Habits in Kindergarten Children in Hong Kong

Objectives: The purposes of the present study were to investigate the characteristics of physical activity, sedentary behaviour, and sleep habits in Hong Kong kindergarten children, as well as to explore the associations among these variables. Methods: Kindergarten children aged between 3 and 5 years in Hong Kong participated in the present study. Participants were instructed to wear an accelerometer to monitor their physical activity level for 7 days. The screen time and Children's Sleep Habit Questionnaires (CSHQ) were completed by their parents. Results: Totally 81 children provided valid accelerometer data, of whom only 32.1% of children met the World Health Organization (WHO) physical activity recommendation, i.e., 60 minutes of moderate-to-vigorous physical activity (MVPA) per day. Nearly 73% of children in our study did not match the WHO guideline of having less than 60 minutes screen time per day. For the CSHQ data, approximately 25.9% (18.5%) of children did not meet the WHO guideline of having 10-13 hours' sleep on weekdays (weekends). Screen time has positive associations with sleepdisordered breathing, whereas sedentary behaviour was positively associated with daytime sleepiness and total score of CSHQ. Low-intensity physical activity was positively associated with sleep onset delay and negatively associated with sleep duration. No significant association was found between MVPA and sleep characteristics. Conclusion: The majority of kindergarten children in Hong Kong in the present study did not meet the WHO guidelines on physical activity, screen time, and sleep duration. Both sedentary behaviour and low-intensity physical activity were associated with certain sleep problems.