Too little sleep is bad for you. You probably knew that already.
But what about too much sleep? Can too much sleep make you tired?
Surely, something that everyone is encouraged to get plenty of can’t be that bad if you get a bit more than usual.
True, oversleeping is not nearly as bad as sleep deprivation, which is associated with irritability, poor concentration, obesity, dementia and a wide range of long-term health problems.
But it is not entirely harmless.
Research has linked oversleeping to an increased risk of depression, diabetes and heart disease. It can even lower your lifespan.
But it’s not very clear whether these effects are directly caused by oversleeping or by lifestyle factors such as financial problems, illness and depression that can make you sleep too much.
One direct effect that researchers agree on though is that too much sleep makes you tired.
How much sleep is too much?
Before we discuss how fatigue and oversleeping are connected, it’s important to define what ‘too much’ actually entails.
Is it 8 hours? Nine? Thirteen?
The recommended sleep period for most people ranges between 7 and 9 hours. Below that, you are likely not getting enough shuteye.
Beyond that, you should probably cut back on your sleep hours.
It’s normal to oversleep during certain situations like when you are sick or very tired. In fact, it can help your body heal and recover faster.
But sleeping in just because you want to get some extra sleep has a surprising effect of making you feel lethargic and tired throughout the day.
Why does that happen? Shouldn’t sleeping longer make you feel more rested?
Why oversleeping causes fatigue
It’s a case of confusing your internal body clock.
Your sleep/wake rhythm is controlled by the circadian pacemaker, a bunch of nerve cells in the hypothalamus part of the brain.
In addition to waking you up and making you sleepy, they also signal other body cells to ramp up energy production (in the morning) or produce less energy (at bedtime).
When you sleep past your usual wakeup time, you throw off your circadian rhythm. This affects your energy levels.
So while you groggily open your eyes at 11am, your body actually woke up at your usual 7am and has been running at full energy since.
The result is a low-energy fatigued experience for most of the day.
You’ll also probably feel more irritable, work less and have trouble concentrating.
If you keep up with the late mornings, the effects can get more serious.
Long term effects of oversleeping
Research has shown a link between chronic oversleeping and various health problems such as obesity, depression, heart disease and diabetes. You might also start experience memory problems.
If you are already suffering from depression, oversleeping (which your depression could be causing) will make it worse.
Oversleeping can also cause or worsen back pain. If you have back pain, being (safely) active is the best way to treat it.
How to stop oversleeping
The first step is to find out what’s causing it.
Perhaps it’s your work hours. People who work until late or during the night shift are more likely to oversleep.
You could also be sick or experiencing the symptoms of depression.
In some cases, it could be a sleep disorder.
If you suspect it is one of the last two, see a doctor to get the root issue diagnosed and treated.
For most people however, it’s simply a matter of poor sleep habits. You don’t sustain a predictable sleeping routine, constantly confusing your circadian pacemaker.
This is especially common during the weekends when we love to justify sleeping in with our new duvet for night sweats.
Sure, you deserve it but it is ruining your sleep routine and making your weekend feel lethargic.
Here are a few tips to stop oversleeping.
- If you sleep in on the weekend, it should not be for more than an hour. This ensures your internal clock stays stable from the weekdays to the weekend.
- Maintain a predictable bedtime every day, even on the weekends. If you want to watch a movie or play a game on Friday or Saturday, do not stay up for more than an hour past your usual bedtime.
- Avoid excess intake of alcohol especially in the evening. It can make you sleep too much. Also avoid caffeine too close to bedtime.