Eight is great but studies show otherwise

Image via Thinkstock
Image via Thinkstock

Eight hours of sleep is actually not the magic number

By Carlos Bilan, Staff Writer

You probably have heard that you need at least eight hours of sleep per night. Anything under that is considered a lack of sleep. But is that really true?

Well, if you think that is unachievable, then I have good news for you. Studies have now shown that seven hours and 30 minutes is actually the optimal duration of sleep. Not only that, but eight hours of sleep is actually not so great. So why does the best sleep duration happen to be half an hour less than what you originally thought? Well, the answer is linked to our sleep cycles.

“Seven and a half hours is a good benchmark, because the average person goes through five 90-minute sleep cycles alternating between sleep (non-REM) and deep sleep (REM),” wrote Kevin Philips in a blog for the Alaska Sleep Education Centre.

You might be thinking, “well, that’s awfully specific!” Don’t worry, 7.5 hours is a guideline and it’s really no different from exactly 8 hours, which is easy to say but not so easy to achieve. Well, thankfully, having 30 minutes less from what you initially thought is actually more beneficial to your health.

Another sleep expert supports the 7.5 hours magic number: Michael Breus (PhD, D, ABSM) from WebMD wrote: “you need about 7.5 hours of sleep each night, and if you count backwards from when you have to wake up, you can figure out what time you need to go to sleep in order to wake more easily.”

If you have slept for 8 or 10 hours and still feel exhausted or groggy, now you know why. It’s not due to needing more sleep but rather that you woke up during a deep sleep. On the other hand, if you wake up during your light sleep cycle, then you find it is easier to open your eyes and get up.

Now, this 7.5 hours of sleep is actually recommended for young adults (18–25 years old) and adults (26–64 years old). According to a press release from the National Sleep Foundation, those who are 17 or under need at least 8 hours of sleep. The younger you are, the more sleep you need! This is also linked to their different sleep cycles. In fact, school age children (6–13) need at least 9 hours of sleep. Luckily for adults, the perks of growing up include not needing too much sleep to be an effective member in society.

This does not imply that it is okay to sleep for either 1.5 hours, 3 hours, 4.5 hours, or 6 hours. You probably will wake up easily, but you will be deprived of sleep. You might even be one of those people who can brag about getting less than 6 hours of sleep and still doing great in college and work. However, this thought can be detrimental to your mental health.

Once you lose focus when doing a job, you will find it really difficult to regain focus. Not only that, you will not even notice your decrease in performance. According to a press release by the Society for Neuroscience: “Sleep-deprived workers may not know they are impaired […] The periods of apparently normal functioning could give a false sense of competency and security when, in fact, the brain’s inconsistency could have dire consequences.”

Just keep in mind that too little of a good thing is bad for your health. Personally, I have tried timing my sleep and setting an alarm that will ring 7.5 hours after. Sometimes, I wake up even before my alarm rings and I’m wide awake. Or when my alarm rings, it just feels easier to get up. Try it yourself and see if it makes a difference. I can vouch that it has for me.