Why Do Human Beings need to Sleep? As today is Worlds Sleep Day.

When you’re scrambling to meet the demands of a busy schedule, cutting back on sleep may seem like the only answer. Sacrificing an hour or two of rest in order to get more done may sound like a reasonable trade-off. But the truth is that even minimal sleep loss takes a toll on your mood, energy, mental sharpness, and ability to handle stress. And over the long-term, chronic sleep loss wreaks havoc on your health.

By understanding your nightly sleep needs and what you can do to bounce back from chronic sleep loss, you can finally get on a healthy sleep schedule.

Sleep is a necessity, not a luxury

The quality of your sleep directly affects the quality of your waking life, including your productivity, emotional balance, creativity, physical vitality, and even your weight. No other activity delivers so many benefits with so little effort!

Sleep isn’t merely a time when your body shuts off. While you rest, your brain stays busy, overseeing a wide variety of biological maintenance that keeps your body running in top condition, preparing you for the day ahead. Without enough hours of restorative sleep, you won’t be able to work, learn, create, and communicate at a level even close to your true potential. Regularly skimp on “service” and you’re headed for a major mental and physical breakdown.

The good news is that you don't have to choose between health and productivity. As you start getting the sleep you need, your energy and efficiency will go up. In fact, you're likely to find that you actually get more done during the day than when you were skimping on shuteye.

Myths and Facts about Sleep

Myth 1: Getting just one hour less sleep per night won’t affect your daytime functioning. You may not be noticeably sleepy during the day, but losing even one hour of sleep can affect your ability to think properly and respond quickly. It also compromises your cardiovascular health, energy balance, and ability to fight infections.

Myth 2: Your body adjusts quickly to different sleep schedules. Most people can reset their biological clock, but only by appropriately timed cues—and even then, by one or two hours per day at best. Consequently, it can take more than a week to adjust after traveling across several time zones or switching to the night shift.

Myth 3: Extra sleep at night can cure you of problems with excessive daytime fatigue. The quantity of sleep you get is important, sure, but it's the quality of your sleep that you really have to pay attention to. Some people sleep eight or nine hours a night but don’t feel well rested when they wake up because the quality of their sleep is poor.

Myth 4: You can make up for lost sleep during the week by sleeping more on the weekends. Although this sleeping pattern will help relieve part of a sleep debt, it will not completely make up for the lack of sleep. Furthermore, sleeping later on the weekends can affect your sleep-wake cycle so that it is much harder to go to sleep at the right time on Sunday nights and get up early on Monday mornings.

There is a big difference between the amount of sleep you can get by on and the amount you need to function optimally. Just because you're able to operate on seven hours of sleep doesn't mean you wouldn't feel a lot better and get more done if you spent an extra hour or two in bed.

While sleep requirements vary slightly from person to person, most healthy adults need between 7.5 to 9 hours of sleep per night to function at their best. Children and teens need even more (see Average Sleep Needs table below). And despite the notion that our sleep needs decrease with age, older people still need at least 7.5 to 8 hours of sleep. Since older adults often have trouble sleeping this long at night, daytime naps can help fill in the gap.

The best way to figure out if you're meeting your sleep needs is to evaluate how you feel as you go about your day. If you're logging enough hours, you'll feel energetic and alert all day long, from the moment you wake up until your regular bedtime.

Think six hours of sleep is enough?

Think again. Researchers at the University of California, San Francisco, discovered that some people have a gene that enables them to do well on six hours of sleep a night. This gene, however, is very rare, appearing in less than 3% of the population. For the other 97% of us, six hours doesn’t come close to cutting it.

Signs that you’re not getting enough sleep

If you’re getting less than eight hours of sleep each night, chances are you’re sleep deprived. What’s more, you probably have no idea just how much lack of sleep is affecting you.

How is it possible to be sleep deprived without knowing it?

 Most of the signs of sleep deprivation are much more subtle than falling face first into your dinner plate. Furthermore, if you’ve made a habit of skimping on sleep, you may not even remember what it feels like to be wide-awake, fully alert, and firing on all cylinders. Maybe it feels normal to get sleepy when you’re in a boring meeting, struggling through the afternoon slump, or dozing off after dinner, but the truth is that it’s only “normal” if you’re sleep deprived.

You may be sleep deprived if you...

    Need an alarm clock in order to wake up on time

    Rely on the snooze button

    Have a hard time getting out of bed in the morning

    Feel sluggish in the afternoon

    Get sleepy in meetings, lectures, or warm rooms

    Get drowsy after heavy meals or when driving

    Need to nap to get through the day

    Fall asleep while watching TV or relaxing in the evening

    Feel the need to sleep in on weekends

    Fall asleep within five minutes of going to bed

The effects of chronic lack of sleep

While it may seem like losing sleep isn't such a big deal, sleep deprivation has a wide range of negative effects that go way beyond daytime drowsiness. Lack of sleep affects your judgment, coordination, and reaction times. In fact, sleep deprivation can affect you just as much as being drunk.

The effects include:

    Fatigue, lethargy, and lack of motivation

    Moodiness and irritability

    Reduced creativity and problem-solving skills

    Inability to cope with stress

    Reduced immunity; frequent colds and infections

    Concentration and memory problems

    Weight gain

    Impaired motor skills and increased risk of accidents

    Difficulty making decisions

    Increased risk of diabetes, heart disease, and other health problems

Improving sleep quality

It's not just the number of hours in bed that's important—it's the quality of those hours of sleep. If you're giving yourself plenty of time for sleep, but you're still having trouble waking up in the morning or staying alert all day, you may not be getting quality sleep.

The most damaging effects of sleep deprivation are from inadequate deep sleep. Deep sleep is a time when the body repairs itself and builds up energy for the day ahead. It plays a major role in maintaining your health, stimulating growth and development, repairing muscles and tissues, and boosting your immune system. In order to wake up energized and refreshed, getting quality deep sleep is essential.

Factors that can lead to poor or inadequate deep sleep include:

Being woken during the night by outside noise, for example, or in order to care for a crying baby.

Working night shifts or swing shifts. Getting quality deep sleep during the day can be difficult, due to light and excess noise.

Smoking or drinking in the evening. Substances like alcohol and nicotine can disrupt deep sleep. It’s best to limit them before bed.

Exposure to artificial light at night— especially the light from electronic devices, including TVs, computers, tables, and mobile phones.