The impact of evening rituals on adolescent sleep has been revealed.

Sleep hygiene is generally understood as a set of established habits, behavioral norms, and environmental conditions that promote and ensure a sound night's rest. For younger generations, key sleep hygiene recommendations traditionally boil down to the following: avoid using electronic devices, avoid physical activity, and avoid eating within an hour of bedtime.

A new study conducted at the University of Otago in New Zealand aimed to examine how closely adolescent children adhere to these guidelines and how this affects the duration and effectiveness of their sleep.

The rationale for these established guidelines is that screens can suppress melatonin production and disrupt circadian rhythms, physical activity can keep the body in an agitated state, and eating foods, especially those containing caffeine or sugar, can disrupt the natural onset of sleep.

A significant amount of data supporting these guidelines has been collected through questionnaires and studies, which lack high reliability and do not establish causal relationships. The aim of this study was to objectively test whether common pre-bedtime activities are actually harmful, using rigorous assessment tools.

An eight-night experiment was conducted with 83 New Zealand residents aged 11 to 15. For four nights, they wore wearable cameras and were also monitored by fixed cameras in their bedrooms. Video footage was used to record moderate-to-vigorous physical activity in the last hour before bed, as well as their use of electronic devices in bed.

Wrist-mounted accelerometers tracked sleep onset, total duration, and quality across all eight nights. Using retrospective dietary analysis, the researchers recorded what the children ate and drank before bed. They compared each child's behavior on different nights with corresponding indicators of their nighttime rest.

The results revealed that 99% of study participants used phones and other screen devices before bed almost every night. The average duration of such use was approximately 32 minutes. However, this did not significantly impact overall sleep duration or quality; however, on such nights, children needed an average of 23 minutes longer to fall asleep.

Only 22% of children engaged in moderate- or vigorous-intensity physical activity before bed, and these were sporadic and short-lived. On nights when children exercised, their sleep duration increased by approximately 34 minutes, although this increase was not associated with other sleep parameters.

Regarding food and beverage consumption, two-thirds (63%) of respondents ate food, mostly snacks, before bed. No significant association was found between food or beverage consumption, including those containing caffeine, sugar, or fat, and sleep quality.

The study did not establish causality, but only found associations between the behaviors mentioned and sleep. Other limitations of the study include that, although the sample was ethnically diverse, it was dominated by families of high socioeconomic status, and the dietary data were based on self-reported data rather than video recordings, which reduces their accuracy.

The findings should be treated with a degree of caution. Further research is needed. The research team is currently conducting a study involving children aged 10 to 15 years and hopes that its results will help refine sleep recommendations for families.

However, the study's findings suggest that existing sleep hygiene guidelines may be overly strict. In practice, such behavior had little impact on the duration or quality of children's rest, with the exception of a slight delay in falling asleep caused by using gadgets. These recommendations likely require revision, and the emphasis should shift from absolute prohibition to achieving balance and moderation.