How much sleep did you get last night? What about the night before? How much sleep do you actually need?
Keeping track of your sleep schedule may not be a top priority, but getting enough sleep is critical to your health in many ways.
You may not realize it, but the amount of sleep you get can affect everything from your weight and metabolism to your brain function and mood.
For many people, wake-up time is a constant.
What time you go to sleep, however, tends to vary depending on your social life, work schedule, family obligations, the newest show streaming on Netflix, or simply when you start to feel tired.
But if you know what time you have to get up, and you know you need a specific amount of sleep to function at your best, you just need to figure out what time to go to bed.
In this article, we’ll help you understand how to calculate the best time to go to bed based on your wake-up time and natural sleep cycles.
We’ll also take a closer look at how your sleep cycles work and how sleep can affect your health.
How much sleep you need changes throughout your lifetime. An infant may need up to 17 hours of sleep each day, while an older adult may get by on just 7 hours of sleep a night.
But an age-based guideline is strictly that — a suggestion based on research of how much sleep you may need for optimal health as your body’s needs change.
According to the American Academy of Pediatrics and the CDC, these are the general sleep guidelines for different age groups:
- Birth to 3 months: 14 to 17 hours
- 4 to 11 months: 12 to 16 hours
- 1 to 2 years: 11 to 14 hours
- 3 to 5 years: 10 to 13 hours
- 6 to 12 years: 9 to 12 hours
- 13 to 18 years: 8 to 10 hours
- 18 to 64 years: 7 to 9 hours
- 65 years and older: 7 to 8 hours
Everyone’s sleep needs are different, even within the same age group.
Some people may need at least 9 hours of sleep a night to feel well rested, while others in the same age group may find that 7 hours of sleep is just right for them.
The biggest question is how you feel when you get various amounts of sleep. Here’s what to keep in mind when evaluating your own sleep needs:
- Do you feel rested after 7 hours of sleep, or do you need at least 8 or 9?
- Are you having any daytime drowsiness?
- Are you reliant on caffeine to get you going throughout the day?
- If you sleep with someone else, have they noticed you having any sleeping issues?
Sleep deprivation is a real thing for some, especially as work and life stress builds up. Getting too little sleep can affect many of your body’s systems and restorative functions.
You may also be getting too little sleep due to:
Some signs you may not be getting enough sleep include:
A 2020 sleep study showed that sleep deprivation doubled the odds of making placekeeping errors and tripled the number of lapses in attention.
Sleep and mental health are closely connected, with sleep disorders contributing to depression and anxiety. Sleep is one of the most important factors in our overall health.
Bedtimes are based on:
- your wake-up time
- completing five or six 90-minute sleep cycles
- allowing 15 minutes to fall asleep
When you fall asleep, your brain and body go through several cycles of sleep. Each cycle includes four distinct stages.
- The first three stages are part of non-rapid eye movement (NREM) sleep.
- The last stage is rapid eye movement (REM) sleep.
The NREM stages used to be classified as stages 1, 2, 3, 4, and REM. Now it’s generally classified in this way:
- N1 (formerly stage 1): This is the first stage of sleep and the period between being awake and falling asleep.
- N2 (formerly stage 2): The onset of sleep begins at this stage as you become unaware of your surroundings. Your body temperature drops slightly, and your breathing and heart rate become regular.
- N3 (formerly stages 3 and 4): This is the deepest and most restorative sleep stage during which breathing slows, blood pressure drops, muscles relax, hormones are released, healing occurs, and your body becomes re-energized.
- REM: This is the final stage in the sleep cycle. It takes up about 25 percent of your sleep cycle. This is when your brain is most active and dreams occur. During this stage, your eyes move back and forth rapidly under your eyelids. REM sleep helps boost your mental and physical performance when you wake up.
It takes, on average, about 90 minutes to go through each cycle. If you can complete five cycles a night, you’d get 7.5 hours of sleep a night. Six full cycles are about 9 hours of sleep.
Ideally, you want to wake up at the end of a sleep cycle instead of in the middle of it. You usually feel more refreshed and energized if you wake up at the end of a sleep cycle.
Sleep is crucial for many reasons. A good night’s sleep:
- regulates the release of hormones that control your appetite, metabolism, growth, and healing
- boosts brain function, concentration, focus, and productivity
- reduces your risk for heart disease and stroke
- helps with weight management
- maintains your immune system
- lowers your risk for chronic health conditions, such as diabetes and high blood pressure
- improves athletic performance, reaction time, and speed
- may lower your risk of depression
To improve your sleep health, consider the following tips.
During the day
- Exercise regularly, but try to schedule your workouts at least a few hours before you go to sleep. Exercising too close to bedtime may lead to interrupted sleep.
- Increase your exposure to sunlight or bright lights during the day. This can help maintain your…