Sleeping hours: what is the ideal number and how does age impact this?

Abstract

The objective of this narrative review paper is to discuss about sleep duration needed across the lifespan. Sleep duration varies widely across the lifespan and shows an inverse relationship with age. Sleep duration recommendations issued by public health authorities are important for surveillance and help to inform the population of interventions, policies, and healthy sleep behaviors. However, the ideal amount of sleep required each night can vary between different individuals due to genetic factors and other reasons, and it is important to adapt our recommendations on a case-by-case basis. Sleep duration recommendations (public health approach) are well suited to provide guidance at the population-level standpoint, while advice at the individual level (eg, in clinic) should be individualized to the reality of each person. A generally valid assumption is that individuals obtain the right amount of sleep if they wake up feeling well rested and perform well during the day. Beyond sleep quantity, other important sleep characteristics should be considered such as sleep quality and sleep timing (bedtime and wake-up time). In conclusion, the important inter-individual variability in sleep needs across the life cycle implies that there is no “magic number” for the ideal duration of sleep. However, it is important to continue to promote sleep health for all. Sleep is not a waste of time and should receive the same level of attention as nutrition and exercise in the package for good health.

Inter-correlations Among Clinical, Metabolic, and Biochemical Parameters and Their Predictive Value in Healthy and Overtrained Male Athletes: The EROS-CORRELATIONS Study

“…Sleep quality was strongly correlated with better psychological outcomes, including lower depression and fatigue, and higher vigor, indicating that sleep quality led to a global improvement in mood, similarly to what has been unanimously observed (49,55,(57)(58)(59). We speculate that sleep duration was not demonstrated to a major factor of mood states or any other characteristic in athletes because in higher quality sleep duration tends to play a less important role (60,61).…”

Sleep and Its Importance for Health-Related Quality of Life in 3–10-year-old Children

“…In a systematic review, longer sleep duration has been found to be related with better emotional regulation and quality of life in 5-17-year-old children [26]. The overall sleep duration for the children in the present study was 9-11 hours per night, which is in line with general sleep duration recommendations [2,27], but contrasts with other studies describing less sleep duration in the latest decennium [7,28]. Longer sleep duration was seen in younger children compared to older.…”

Sleep and Early Brain Development

“…In 2017, the NSF published evidence-based recommendations and guidance to the public regarding indicators of good sleep quality for children under 5 years of age [14], which are summarized in Table 1. Nevertheless, it is worth noting that even though the normative sleep duration values are helpful and inform what constitutes the norm and what is considered outside the norm for a given age, these references provide norms at the population level standpoint and need to be individualized for each patient in the clinical setting [15].…”