Sleep needs are determined by different factors, mainly age, individual and genetic characteristics, the duration of previous wakefulness period, as well as an internal biological clock that sets a daily, or circadian rhythm.
Age and sleep: close to birth babies sleep 16 to 18 hours a day in time intervals spread around the clock. The time spent asleep decreases gradually, around 12-13 hours at 1 year of age, 9 hours during adolescence, and around 8 hours thereafter. The sleep needs remain almost the same during adulthood, only the ability to sleep may decline with aging.
People have individual sleep needs, some of them inherited. Although the average population need is around 7 and a half hours, some people may thrive with as little as 4 or 5 hours of sleep, while others may need as much as 9 and a half hours. No matter what the individual specific needs are, there is a wake-sleep balancing process, which works in such a way that upon waking up the sleep need is exhausted and starts to accumulate as the day unwinds, until one is ready to sleep again. When a person loses sleep the need increases and there is a tendency to fall asleep earlier, or even at otherwise unexpected times during the day.
Another clear factor ruling over sleep is an internal, biological clock. The duration span of this internal clock is individual and is usually slightly longer than 24 hours. Thus, without any external influence the go to bed time might move slightly down each day, causing the wake up time to move accordingly. When this happens, the sleep-wake cycling pattern is called free running. However, the great majority of human beings keep a schedule that is mostly sleeping during the night and being awake during daylight time.
The intrinsic clock syncs everyday with external factors like light and dark hours, work schedule, meals, and social cues. The ability of the clock to sync or reset in order to keep in line with the external cues and allow for a regular sleep-wake schedule represents an important component of our quality of life.
Personal motivation can override individual sleep needs in order to keep us awake despite the fact that the body is telling us it is sleep time. This motivation can result from our will to work or study instead of sleeping, or even the ambition to perform better, or the basic need to stay awake in order to be safe, like when driving during late hours, when we actually need to sleep. All scientific findings indicate that severe sleep debt overrides any motivational factors and at last we fall asleep involuntarily.
How can you improve your sleep?
Our expertise lies in assessing sleep and how different factors work together to influence a person’s sleep. Our Sleep-Life Balance Program helps to pinpoint flaws in sleep and help correct them.