How Much Sleep Is Enough? 8 Hours, Give Or Take An Hour

Reshot/Elina Djan

Eight hours – that’s been the recommended amount of sleep for years, and it’s pretty specific. Getting those hours in is important because sleep is more than just a luxury. It comes back to affect everything, from your appetite and metabolism to your learning ability and memory retention. Yes, you need it, and eight hours is a good goal, but one you should approach with some flexibility.

How Much Is Enough

During a regular night’s sleep, you will pass through five or six sleep cycles, and you enter five sleep stages during each cycle. A normal cycle lasts about 90 minutes. If you do the math, five 90-minute sleep cycles take about 7.5 hours. Given that a sleep cycle or two may run short or long depending on the person, an average adult needs about eight hours of sleep. However, anywhere between seven and nine hours is enough time for the body to recharge.

Most people struggle with sleep deprivation, which is anytime you get less than six hours of sleep in an evening. Seven to nine hours is the body’s “magic zone,” where it has time to heal, rejuvenate and cleanse itself. If you step outside that zone (on either end), there will be not-so-fun consequences.

Your Body Without Sleep

Your mood and emotional stability rely on sleep. The area of your brain that processes emotions gets overly sensitive to negativity when you’re tired. Emotional stability becomes even more difficult because, at the same time, the logic and reasoning center of your brain becomes less active. That’s why irritability, sadness and aggression are far more common when you’re tired.

Consistent lack of sleep can also lead to an expanding waistline because, without sleep, hunger hormones increase and satiety hormones decrease. You’re left hungrier than usual, and your brain gets bigger rewards from high-fat, sugary foods when you’re tired.

Reshot/Jordan Vanderzalm

Sleep is essential for memory consolidation, learning and muscle recovery, and it impacts your physical appearance and prolonged health. Sleep deprivation contributes to illnesses and disorders like diabetes, heart disease, high blood pressure and stroke.

However, it is possible to have too much of a good thing. Sleeping too much — more than 10 hours a day — can have serious health consequences, too. We’re not talking about an occasional sleep-in session, but consistently sleeping more than necessary. Depression (which can cause the excessive need to sleep), weight gain and heart problems are only a few of the issues that may come from excessive sleep.

So, you need it, but how do you get that eight hours?

Healthy Sleep Habits And Environment

Your habits, behaviors and sleep environment all affect your ability to get the rest you need. To create the best possible sleep conditions, try:

Getting comfortable. Your body can’t relax and fall asleep if you’re not comfortable. A mattress that caters to your weight and preferred sleep position can make a big difference. You can also help your body get comfortable by but turning down the thermostat and blocking out all light.
Heading outside. Natural light helps set your circadian rhythm, which controls the sleep-wake cycle. Light exposure early in the day helps regulate the timing of sleep hormones at night.
A consistent sleep schedule. Try to go to bed and wake up at the same time every day, including weekends. You can also incorporate a relaxing bedtime routine to help relieve stress before bed and trigger the release of sleep hormones.

Eight hours of sleep is like an archery target. You aim for the middle and if you fall a little high or low, you’re still close enough to get the benefits. It may take consistent effort, but for your mental and physical health, it’s worth it.

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