How Much Can an Extra Hour of Sleep Change You

Everyone knows that missing a whole night of sleep can cause problems. You may not realize that getting an hour less sleep than you need each night can cause issues as well. Here is a look at some of the problems that happen when you incur a sleep debt and some tips on how to optimize the amount of sleep you get.

What Does a Sleep Deficit Do

Conventional medical wisdom suggests that the average adult needs around 7-9 hours of sleep to stay healthy. However, more than 60 percent of women don’t meet this basic metric. ( A combination of a busy schedule, competing distractions like smart devices, and a high-stress lifestyle can all add to this increasing sleep debt.

One of the most difficult things about a sleep debt is that the longer it goes on, the less you remember how you felt when you were well-rested. As symptoms like lack of focus, irritable emotions, and loss of energy continue to increase, your perspective of what is normal will also shift. This can make it hard to recognize the problem until it is significant.

What are Some Symptoms of Sleep Debt

There are a host of sleep studies that have attempted to look at the effects of adding or subtracting a single hour of sleep from the test subjects.

  • A study sponsored by the BBC ( had half of their six test subjects add an hour to their nightly sleep schedule while the other half continued to sleep their alloted 6.5 hours. Both groups would spend their nights being monitored by a sleep clinic. Mental agility went up in those who got more sleep.

Even more interesting, blood tests were able to show more than 500 genes whose expressions were switched on or off based on how much the subject slept. Some of these genes were linked to serious chronic conditions like cancer or diabetes.

  • A study at Harvard (–nights-sleep.html) was able to show that the two main factors that mattered for sleep benefit were that you got the right number of hours and that you dreamt during your sleep. The university gave people a task that relied on visual cues and memory. They had to complete the task in the morning, in the evening, and again the next morning. Those who napped and dreamt were better late in the evening and had a 50 percent increase in memory recall over non-nappers the next morning.
  • A study in Tel Aviv ( looked at the importance of sleep in children. Kids were told to stay up later or go to bed earlier than they normally would and were given smart watches to monitor the actual amount of sleep they got. Elementary-age kids given testing during the day were shown to drop in IQ and performance levels by as much as two grade levels when they had a chronic drop in sleep lasting the duration of the study.
  • An NIH summary chapter ( that documents the economic impact of sleep loss has shown that it is the main culprit in approximately 20 percent of all car crashes. Sleep deprivation has also been shown to be a major factor in some of the best-known disasters with known human error. This includes the Exxon-Valdez oil spill.

What are the Recommended Guidelines for Sleep by Age

According to WebMD (, the breakdown for sleep changes at every major change in maturity level in your life. This also includes major life changes like the first three months of pregnancy. The recommendations are as follows:

  • Infants tend to sleep between 12 and 15 hours per day in 1-4 hour bursts.
  • Toddlers perform best with 11-14 hours per day. This is now shifted mainly to a long stretch at night with a midday nap.
  • Preschoolers can get by with a sleep total between 10 and 13 hours per day. Naps will begin to vary based on the kid; some will do better with one long nighttime stretch while others are best when they get a nap each day.
  • From elementary into middle school, the recommendation is between 9 and 11 hours of sleep.
  • Teens take a sharp drop in the number of required hours, going down to 8.5 to 9.5 hours as an average.
  • Adults, once again, should try for between 7 and 9 hours of sleep.
  • Pregnant women should consider adding 2 or more hours to their total sleep per day.

How Do You Improve Your Sleep Quality

As important to the equation as number of hours of sleep, quality of sleep is very important. SleepMentor ( website offers the following tips to improve the quality of sleep you’re getting each night:

  • Avoid stimulating chemicals like caffeine and nicotine.
  • Make your room as dark and as quiet as possible.
  • Create a bedtime routine that helps to lower your stress hormones before bed. Take a bath, read a book, and avoid work.
  • If you’re not tired, don’t lay in bed tossing and turning. Do something and return when you’re sleepy.
  • Turn the clock away from you if you’re struggling to sleep.
  • Try and keep the same bedtime and waking hours.
  • Keep naptimes to early in the day.
  • Make dinner a light meal.
  • Stay hydrated but don’t drink a lot near bedtime.
  • Plan your workouts for early in the day.
  • See a sleep expert if you believe you are suffering from more serious conditions like narcolepsy or apnea.

Another important thing to consider is turning off your devices a few hours before bed when possible. The blue light wavelengths in smartphones and tablets have been shown to trick the brain into thinking that it is daytime and reduce or prevent the release of sleep-inducing melatonin hormones in the body. This essentially leads to a chronic state of jet lag.

There are a lot of good reasons to try and add an hour of sleep to your schedule and that of your loved ones. If this is not a possibility, following smart strategies to try and increase the amount of quality REM sleep that you’re getting will also work well.