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March 9, 2023

Ask the expert: Why do teenagers need more sleep?

Hanne Hoffmann, assistant professor of animal science

In recognition of Sleep Awareness Week and Daylight Savings Time, which both begin March 12, Michigan State University expert Hanne Hoffmann explains why teenagers need more sleep than other age groups. Hoffman, an assistant professor in the College of Agriculture and Natural Resources, also discusses the specific impact sleep has in shaping the mental health of youth.


Why do teenagers need more sleep?


During puberty you need as much sleep, if not more, than children younger than you. What we often forget is that you don’t only change physically during puberty, but your brain is changing a lot too, which requires additional sleep. 


Scientifically, it’s been shown that teenagers need between eight to 10 hours of sleep a night. However, due to early school start times, about 70% to 80% of teenagers get less than eight hours of sleep and 30% to 40% of teenagers get as little as six hours of sleep per night.


How do early start times contribute to sleep deprivation for teenagers?


This is a very serious health problem because it’s not just one night that teenagers don’t get enough sleep — it’s most nights of the week. This lack of sleep negatively impacts teenagers’ physical and mental maturation, but also affects how well they do in school. 


What would be an ideal start time for schools?


In Michigan, the current average high school start time is 7:55 a.m. Ideally, high schoolers would not start school prior to 9 a.m. 


What are circadian rhythms and how do they play into this?


We all can recognize our daily sleep-wake patterns. We wake up in the morning and we go to bed in the evening. This rhythm is called a circadian rhythm. For you to wake up every morning, you need little clocks within every single cell of your body to tell you it’s time to wake up.


When you’re a teenager, these clocks run slower than for adults. In adults, these clocks run very close to 24 hours. If you were stuck in a completely dark environment without the sun rising every morning, you would still wake up every single morning at about the same time. Teenagers, on the other hand, would wake up about three hours later.


How does lack of sleep affect students’ well-being and mental health?


Lack of sleep increases your risk of cardiovascular dysfunction, obesity, depression and violence. When you’re sleep-deprived, you are not good at problem solving and you are not good at handling difficult situations. Sleep-deprived teenagers also don’t learn as much and underperform in school.


What can parents do to help?


Parents can encourage their teenagers to go to bed earlier. This will help, but only partially due to the natural delay in their body rhythms. Teenagers should also avoid drinking caffeinated beverages in the afternoon. 


Parents also can consider the lightbulbs in their homes. Blue lights are in most of the common LED bulbs we use. This blue light is great for waking up and giving us energy, but when used at night can make it hard to fall asleep. Using lights that switch color is beneficial because you can switch to red light in the evenings to promote sleep. 




By: Kaylie Crowe

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