Sleep duration among Czech adolescents significantly decreased and insufficient sleep significantly increased between 2014 and 2022, while late bedtimes and social jet lag were associated with higher odds of skipping breakfast, energy drink consumption, alcohol use, reduced psychological wellbeing, low life satisfaction, irritability, and problematic social media and internet gaming use.
Key Findings
Results
Mean sleep duration on school days significantly decreased for both boys and girls between 2014 and 2022.
Boys' school day sleep duration decreased from 8 hours 19 minutes in 2014 to 7 hours 59 minutes in 2022 (p < 0.05).
Girls' school day sleep duration decreased from 8 hours 20 minutes in 2014 to 7 hours 55 minutes in 2022 (p < 0.05).
The sample included 42,101 adolescents aged 10.5–16.5 years from three nationally representative cohorts.
Data were drawn from the Health Behaviour in School-aged Children (HBSC) study cycles conducted in 2014, 2018, and 2022.
Results
Mean sleep duration on non-school days also significantly decreased for both boys and girls between 2018 and 2022.
Boys' non-school day sleep duration decreased from 9 hours 36 minutes in 2018 to 9 hours 23 minutes in 2022 (p < 0.05).
Girls' non-school day sleep duration decreased from 9 hours 58 minutes in 2018 to 9 hours 41 minutes in 2022 (p < 0.05).
Non-school day comparisons were made between 2018 and 2022, not from 2014.
Results
The prevalence of insufficient sleep on school days significantly increased for both boys and girls between 2014 and 2022.
Boys' prevalence of insufficient sleep on school days increased from 35.4% in 2014 to 49.2% in 2022 (p < 0.001).
Girls' prevalence of insufficient sleep on school days increased from 35.1% in 2014 to 51.7% in 2022 (p < 0.001).
By 2022, more than half of girls and nearly half of boys were getting insufficient sleep on school days.
Results
The prevalence of insufficient sleep on non-school days also significantly increased between 2018 and 2022.
Boys' prevalence of insufficient sleep on non-school days increased from 14.9% in 2018 to 18.0% in 2022 (p < 0.001).
Girls' prevalence of insufficient sleep on non-school days increased from 9.8% in 2018 to 13.3% in 2022 (p < 0.001).
Results
Adolescents with late bedtimes had significantly higher odds of multiple adverse health behaviors and wellbeing outcomes compared to those with earlier bedtimes.
Late bedtime was significantly associated with higher odds of skipping breakfast daily, drinking energy drinks daily, and being drunk at least twice in their lifetime (p < 0.001).
Late bedtime was also associated with reduced psychological wellbeing, low life satisfaction, and reporting irritability (p < 0.001).
Problematic social media use and internet gaming were also significantly more common among adolescents with late bedtimes (p < 0.001).
These associations were observed in 2022 data.
Results
Adolescents with social jet lag greater than 2 hours had significantly higher odds of the same adverse health behaviors and wellbeing outcomes as those with late bedtimes.
Social jet lag > 2 hours was significantly associated with daily breakfast skipping, daily energy drink consumption, and lifetime drunkenness of at least twice (p < 0.001).
Social jet lag > 2 hours was associated with reduced psychological wellbeing, low life satisfaction, and irritability (p < 0.001).
Problematic social media use and internet gaming were significantly associated with social jet lag > 2 hours (p < 0.001).
The trend results indicated 'deepening social jet lag' over the study period.
Methods
The study used three nationally representative cohorts of Czech schoolchildren aged 11, 13, and 15 years from the HBSC study cycles of 2014, 2018, and 2022.
The total analysed sample comprised 42,101 adolescents aged 10.5–16.5 years.
The HBSC (Health Behaviour in School-aged Children) study is a cross-national study conducted in multiple cycles.
Age groups studied were 11-, 13-, and 15-year-olds, representing key adolescent developmental stages.
What This Means
This research suggests that Czech teenagers are sleeping less than they used to and that the problem is getting worse. Looking at data collected from over 42,000 young people aged 11 to 15 across three time points (2014, 2018, and 2022), researchers found that the average amount of sleep adolescents get on school nights has dropped by about 20–25 minutes over this period. By 2022, roughly half of all boys and more than half of all girls were not getting enough sleep on school nights — a dramatic increase from about one-third in 2014. Sleep on weekends and holidays also declined, though less steeply.
The research also found that teenagers who go to bed late or who have a large mismatch between their sleep schedules on school days versus free days (called 'social jet lag') are much more likely to engage in unhealthy behaviors and report poorer wellbeing. These adolescents were significantly more likely to skip breakfast, drink energy drinks daily, have been drunk more than once, experience lower psychological wellbeing and life satisfaction, feel more irritable, and engage in problematic use of social media and internet gaming compared to peers with healthier sleep habits.
This research suggests that worsening sleep patterns among teenagers are linked to a range of concerning health and behavioral outcomes. The findings highlight the need for families, schools, and health professionals to work together to help young people maintain recommended sleep durations and consistent sleep schedules, as poor sleep appears to be connected to broader risks for adolescent health and wellbeing.
Sigmund E, Sigmundová D, Voráčová J, Fürstová J, Kalman M, Gobiņa I, et al.. (2026). Trends in sleep patterns among Czech adolescents and their current correlates of late bedtimes and social jet lag: HBSC study 2014-2022.. Central European journal of public health. https://doi.org/10.21101/cejph.a8749