Everybody knows what it’s like to sleep. But do you know why you sleep? It can seem like a total waste of time. Your nervous system, which controls your body’s movements, is almost inactive. Your eyes are closed and your muscles are at rest. You don’t even have any conscious thoughts!
In fact, sleep is essential for your brain and body to perform at their best. In particular, it boosts your memory and your immune system.
Did you know? Humans are the only mammals that choose to delay sleep.
Sleep and memory
One benefit of sleep is that it improves your memory. An experiment by researchers in Germany showed this by teaching three simple skills to a group of babies:
- How to take a mitten off a hand puppet
- How to shake the mitten
- How to put the mitten back on the puppet
After learning these skills, half of the babies took a nap. The other half continued playing.
Later, the babies were shown the puppet and the mitten a second time. The babies who had taken a nap remembered what to do, but the ones who had stayed awake didn’t. The babies who had kept playing didn’t remember. So what does this all mean for you? Well, it suggests that sleep can improve your ability to learn the next day.
Sleep also appears to help with memory consolidation, the process of “storing” ideas in your long-term memory. During the deepest stages of sleep, your brain seems to sort through memories gathered during the day. It then selects the most important ones, strengthens them, and discards the others.
Unfortunately, not everyone gets the same benefits from sleep. A 2007 study found that sleep did not improve learning ability in the elderly. More research is needed to better understand the relationship between age and sleep. But results like these only highlight the importance of sleep for younger people like you.
Did you know? People who don’t get enough sleep are more likely to have bigger appetites. It’s because they have decreased levels of leptin, an appetite-regulating hormone.
Sleep and immunity
Sleep can also help boost your immune system. In other words, if you get regular sleep, you’ll be less likely to get a cold or the flu.
Lack of sleep can lower the production of some of the cells that are used by your immune system. This makes it harder for your body to fight off infectious diseases, which makes you more likely to get sick.
A two-part experiment by researchers in California demonstrated the link between sleep and immunity. First, participants recorded what time they went to sleep and woke up. They also wore a wrist actigraphy, which is a bit like an activity tracker. That way, the researchers could monitor their sleep patterns and their movements while they slept.
In the second part of the study, researchers gave the participants nose drops containing rhinovirus, the virus that causes the common cold. The participants were then quarantined in a hotel for one week to see who would actually come down with a cold. It turned out that those who slept less than seven hours a night were four and a half times more likely to get sick than those who slept seven hours or more!
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As you can see, your body actually accomplishes a lot when you sleep. Sleep boosts your immune system and helps protect you from disease. It strengthens your memory and helps you remember the most important things you did during the day.
Mahatma Gandhi once described how a good night’s sleep made him feel like a brand new person: “Each night, when I go to sleep, I die. The next morning, when I wake up, I am reborn.” It’s not such a crazy idea. Not only does sleep help you learn new things the next day, but it makes it easier to remember what you learned the day before.
About the importance of sleep in general:
About sleep and memory:
About sleep and immunity: