The science of sleep: How many hours do you need?

Conventional wisdom says eight hours is key when it comes to sleep. But recent studies show eight might not be the magic number for everyone. So how do you know you’re getting the sleep you need?

With a simple plan to track your sleeping habits, the right amount of sleep is only a night – or two – away.

track sleep

Sick of hitting snooze? Try tracking your sleep habits to understand how many hours your body needs.

Why is sleep so important?

Most of us agree that we don’t get enough of it. But that dragging, heavy-lidded feeling isn’t the only bad result of sleep deprivation – lack of sleep can lead to serious health risks. Short sleep duration is linked with overeating, diabetes and heart problems, depression and substance abuse, and an increased risk of nodding off at the wheel. (Drivers, take note: the CDC cites tiredness as a factor in up to 5,000 fatalities each year.)

What can sleep do for me?

Not only do healthy sleeping habits help reduce risk for sleep-related accidents and certain health conditions, there are also these upshots:

Sufficient shuteye offers a number of health benefits like these, says the National Sleep Foundation.

How many hours are enough?

Different people need different amounts of sleep. One factor is age: adults generally find 7–8 hours adequate, while active school-age children can require as many as 11 hours. The quality of sleep also affects the quantity you need. Older adults, who often sleep for shorter spans, or those with frequently interrupted sleep won’t feel as rested. And some research has also linked sleeping too much to higher risk for illness, accidents and mortality.

So the question is how to find the right number for you.

Get on track for better sleep.

The key to a good night’s rest? Consistency – and a plan. The National Sleep Foundation outlines a strategy that includes setting a sleep and wake schedule and a regular bedtime routine. (Permission to pamper yourself: a comfortable room, relaxing hot bath and soothing music have all been shown to lead to better shuteye.)

To establish your personal sleep schedule, try recording sleep for even just a week to help identify your circadian rhythm, or body clock. If you find yourself waking up within 10 minutes of your target wake time without the use of an alarm, that’s a good sign you’re on track to healthy sleep.

Technology can help: for example, fitness devices are widely available that offer a window into things like your daily sleep quality and hours. Walgreens’ own Balance Rewards for healthy choices™ platform lets you compare sleep to other vital health metrics, like fitness and weight, to show you how a regular sleep pattern supports your wellness goals – like healthy weight loss. (You can even sync your fitness tracker for automatic entry.)

See this previous Stay Well post for more tips for better sleep.

Balance Rewards for healthy choices™

Walgreens’ Balance Rewards for healthy choices™ program (formerly Steps) is just one tool to help you make healthy choices by rewarding you for tracking sleep, exercise, weight and more. Learn more and get started ›

  • Benjamin

    How do naps fit in? Is 7 hours sleep at night plus a 1 hour afternoon nap equal to 8 hours sleep?

  • Christine Strider

    A BIG let down at the end… Had to read the whole entire to see if there was DETAILED INFO on HOW EXACTLY to TRACK sleep… What methods, exactly… Very VAGUE useless information given. I’ll do my OWN research… Thank you. Sorry I couldn’t benefit from your article… It was all common knowledge already thoroughly already beaten in with myriad articles from every other facet of health literature… Boring. Sorry.

    • Walgreens

      Thanks for the feedback – the focus of this article is on the overall importance of and science behind healthy sleep. Tracking sleep hours is a way to identify your natural sleep/wake cycle but not the focus here. Consistency in sleep patterns as mentioned in the article is the key factor, no matter the tracking method you use. Here’s one source we linked to on tracking to find a target bedtime:

      As far as how naps factor in to sleep hours, more research is needed. Some input from the National Sleep Foundation: [One] “reason there is ‘no magic number”‘ for your sleep results from two different factors that researchers are learning about: a person’s basal sleep need – the amount of sleep our bodies need on a regular basis for optimal performance – and sleep debt, the accumulated sleep that is lost to poor sleep habits, sickness, awakenings due to environmental factors or other causes… Some research suggests that the accumulated sleep debt can be worked down or ‘paid off.’ Does that mean naps can replace sleep hours outright? Not necessarily, but they can be good for your health:

  • Sam Walker

    I did learn something about this article that I can apply on myself. I don’t have the healthiest sleeping habit and I can relate so much when you said something about the dragging, heavy-lidded feeling that is my life every time I wake up. I know a should do something about it because I don’t exercise as at all anymore and I’ve been eating like crazy lately. I always though that being full makes someone feel sleepy which it does but it doesn’t guarantee a good long sleep.

  • vicky

    do you have cream for restless legs

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