For the longest time, we’ve been told that to get adequate rest you need 8 hours of sleep. The notion was that this would improve overall health and cognitive abilities. However, research suggests scientists aren’t too sure about how much sleep you need. Before you determine how much sleep is adequate, this is what you should know.
The Myth Surrounding Our Sleep Cycles
Although 8 hours of sleep has become the recommended period of rest, it seems as though the idea of a consecutive 8 hours of sleep has nothing to do with science or even our innate body rhythm. Instead, as historian Craig Koslofsky revealed, the 8 hours of sleep rule originates from improvement in technology, making it a new invention. In the 1600s, as the urban upper class gained access to better street lighting and domestic lighting, sleep patterns changed.
Before that, many people broke sleep into two four-hour segments, often referred to as first and second sleep.
Studies have revealed that sleeping for a consecutive 8 hours contradicts our physiology. Humans sleep in two-hour periods when sleep is deepest, and the body can “reset.” Outside of these two-hour distinct cycles, sleep is lighter, making it easier to wake from the consecutive 8-hour routine.
However, there are other –– more extensive –– studies that suggest our physiology is to sleep for shorter periods.
Is 8 Hours of Sleep Really Necessary?
When it comes to sleep, healthcare practitioners often recommend eight or more hours for the health benefits. Yet the data surrounding these purported benefits are inconclusive.
Instead, emerging data suggest that 8 hours of sleep could be more detrimental to our overall health. A study published in 2002 revealed that extended periods of rest could be connected to a higher mortality rate. The large-scale study –– which was conducted using 1 million participants –– examined the sleep patterns of the subjects before comparing their mortality rates.
Seven hours of sleep seemed the least detrimental as participants who reported sleeping for 7 hours a night had the lowest mortality rate. Those who slept for 6, 8, or 9 hours had a 15% higher mortality rate. Scientists are unsure if sleeping more or less than 7 hours would shorten your lifespan, as further research –– more substantial research –– would be necessary to determine if 7 hours is the golden number.
How Many Hours Should You Be Sleeping?
If 8 hours of sleep correlates with a higher mortality rate, how much sleep should you aim to have each night?
Ideally, you would think more is better, as many believe beyond diet, the ailments experienced by modern society are rooted in sleep deprivation. That is most likely not the case, as our ancestors shared sleep patterns with our own. Research conducted by UCLA studying contemporary hunter-gatherers shows that many sleep for 7 hours and stay up approximately four hours after dusk. Of course, these patterns changed as the seasons changed. In winter, they would sleep more than in summer, something that was most likely how our ancestors slept.
Considering that most of the information surrounding the 8-hour rule has been disproven, many sleep researchers suggest that the 8-hour rule be used as a gauge rather than a benchmark.
Unfortunately, there isn’t a precise answer regarding how long your should sleep. The only way you would know how long you should sleep is if you test different sleep patterns to determine which reduce your levels of fatigue and improve your overall feeling of vitality.