Are People Taller in the Morning?

3.7 based on 18 ratings

Updated on Jan 22, 2013

Grade Level: 7th and up; Type: Physical Science & Anatomy


We will test whether it is true that humans are taller right after they wake up in the morning than later during the day/night.

Research Questions:

It is said that humans are taller in the morning when they wake up than later during the day. If true, this may be due to gravity compressing on the vertabrae (spine) in our backs as we stand up or sit down during the day. While we are laying down in resting position, the spine is said to “spread out” and decompress, hence the person is taller after lying in bed all night. In fact, astronauts coming back from outer space are a few inches taller than their normal height on earth because there is very very weak gravitational forces in outerspace relative to acceleration and weight; thus there is no compression on the spine. But when they are on earth again, gravity will gradually return them to their normal height. So does this mean that the longer we sleep, the taller we will be? What is the truth?


  • Measuring tapes
  • A few test subjects (the more people; the more accurate results you will have) and a helper for each of them
  • Pen and paper to take notes

Experimental Procedure

*Please be sure that you or a helper measure your test subjects, as self-measurements tend to be wrong.*

  1. Recruit some test subjects who are willing to participate in your experiment to do the following:
  • Have someone else measure their height right after they get out of bed
  • Have someone else measure their height at noon
  • Have someone else measure their height right before they go to bed
  • Write down the time they slept and the time they got out of bed and how many hours of bedrest they got
  • The above should be done everyday for two weeks.
  1. Your test subjects should turn in their findings to you after the week has passed. You should then analyze these results. Find the differences (and similarities) in the height measurements. See whether any of these variations correlate with the amount of hours the test subject was in bed. Does more sleep = a bigger difference?
  2. Record your findings.

Sample Chart

Test Subject #_____


Height Records




Time woke

Time Slept
# Hours of Sleep
Day 1

Day 2

Day 3

Day 4

Day 5

And so on…................

Terms/Concepts: Gravity; Vertabrae (spine); Human Height


Sofia PC is currently a college student with a deep interest in science who is aspiring to become a writer. She writes about all sorts of things across all subjects including, but not limited to; science, crafts, and fashion. She hopes to become a good writer so she can share her thoughts and experiences with the world and future generations.

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