A bedside lamp shines on an empty bed, abandoned due to insomnia.
Centr Team

How did you sleep last night?

Centr Team

You’re losing your smarts. Your strength is decreasing. You're feeling down in the dumps. And fellas... your testicles are shrinking.

No, it's not the end of the world. You're just not getting enough sleep.

None of this is going to happen after just one late night. But consistently poor sleep can have a compounding negative effect on your well-being.

Most sleep problems have straightforward fixes. You can learn about the most common issues and solutions here.

We’re so underslept that the CDC has labeled it a ‘public health epidemic’.

Let’s take a look at 10 things that can happen when you don't get enough shut eye and – on the other side of the pillow – how good things can be when you make sleep a priority.


Luke Zocchi may look good when he’s underslept, but he’s definitely not operating at 100%.

How much sleep do you really need?

As a society, we’re so underslept that the CDC has labeled it a “public health epidemic”. More than one-third of adults aren’t getting enough sleep each night in the US, while almost two-thirds of adults worldwide feel they don’t sleep well.

So how much is enough? Here are the Sleep Foundation’s baseline recommendations:

  • Newborns (0-3 months): 14-17 hours each day
  • Infants (4-11 months): 12-15 hours each day
  • Toddlers (1-2 years): 11-14 hours each day
  • Preschoolers (3-5): 10-13 hours each day
  • School age children (6-13): 9-11 hours each day
  • Teenagers (14-17): 8-10 hours each day
  • Younger adults (18-25): 7-9 hours
  • Adults (26-64): 7-9 hours each day
  • Older adults (65+): 7-8 hours each day

10 ways a lack of sleep is bad for you (and getting sleep is good!)

There isn't really a downside to getting adequate sleep. But a consistent lack of sleep can impact your health and performance in more ways than you might think.


Shhh… memory downloading in process.

1. Your brain deletes memories

When you dream during the REM (rapid eye movement) stage of sleep, your brain is sifting through all the information you came across during the day and processing memories. Sleep poorly and you won’t just struggle to learn new info (so much for that test you were studying for…), but will actually begin forgetting stuff you already know.

A good night’s rest will help you to bank today’s information on your internal hard drive and set you up for a solid day of new learning tomorrow.

2. You’re more likely to get injured

Ever notice that you’re more clumsy when you’re tired? This is because a lack of sleep leads to cognitive impairment, slowing your reaction time and hampering decision-making.

On the workout mat, this could lead to sloppy form and injury. On the job, the consequences can be even more serious. Sleepy employees are “70% more likely to be involved in workplace accidents”, while drivers who get behind the wheel with 6 hours of sleep or less “are 33% more likely to have an accident”.

But if a short ‘power nap’ of 20-30 minutes can improve alertness, reaction time and concentration, just picture what a full night’s sleep can do for your cognitive performance.


Luke’s tips: 1) Go to bed early to avoid injury. 2) Find friends who don’t laugh at your pain.

3. Your brain gets dirty

Your brain has a waste management system and the trash (toxins that build up while you’re awake) gets taken out during deep sleep. Scientists believe disruption to this trash disposal system may contribute to brain disorders.

While research on these connections is ongoing, it’s another good reason to prioritize sleep and let your waste disposal system do its thing.

4. You’re more prone to depression

Just one bad night’s sleep is enough to make you more irritable, angrier, sadder and more stressed. A pattern of poor sleep is linked to severe mental health problems, including higher rates of depression.

On the flip side, your emotional and mental well-being is improved during the REM stage of sleep, helping you to wake up in a better mood.

Sleep and your immune system have a codependent relationship.

5. Your immune system struggles

Drink all the immune-boosting tea you like – if you don’t get enough sleep, you’re probably going to get sick.

This is because sleep and your immune system have a codependent relationship: immune response to an illness (such as a fever) can impact your sleep, while getting plenty of sleep can boost your immune system functioning.

While you’re sleeping, your immune system releases little protective cells that help counter inflammation, infection and the effects of stress. Ahh, feeling better already.

When the donuts start talking back, it’s time to get more sleep.

6. Your hunger hormones are affected

You already know that you’re not going to train at your best when you’re exhausted. This poor performance can mean double trouble for your goals, compounding the impact a lack of sleep is having on your hormones – specifically, a hormone called ghrelin.

When you’re underslept, ghrelin levels go wild, driving your hunger up and sending you into snacking overdrive. Next thing you know, your fitness goal is going backward.

By staying on track with your sleep, you’re setting yourself up to stay on track with your fitness goals.

Let cortisol run wild through your body and you will start to lose muscle, instead of gaining it.

Angie Asche

7. You can lose muscle

Good sleep is essential to repairing and growing muscles. Bad sleep can undo your hard work. That’s because sleep deprivation increases cortisol production.

As our dietitian Angie explains: “Let cortisol run wild through your body and you will start to lose muscle, instead of gaining it.”

That’s why Luke Zocchi takes rest seriously. “We all get caught up on smashing ourselves in the gym, but muscle growth only happens when we rest and get enough sleep.”


Bask in the impressive biceps of a guy who knows how to sleep.

8. Your risk of serious illness increases

When you consistently don’t get enough sleep, you’re increasing your risk of serious illnesses such as obesity, type 2 diabetes, high blood pressure, stroke and heart disease.

Many of these medical issues are weight and diet-related, so you can see how a lack of sleep piles up.

However, experts are increasingly focusing on using sleep to manage and prevent chronic illnesses. For example, optimizing sleep duration and quality may help people with diabetes control blood sugar.


The serene face of a woman who loves to sleep.

9. Your sex drive plummets

If you’re not getting busy sleeping, you’re less likely to be getting busy in bed! And it’s not just because you’re probably too tired for sex.

Sleep is essential for regulating the sex hormones which control libido in both men and women. Get a good night’s rest and you’re more likely to be interested in sex the next day.

10. Your sex organs shrink

Yes, you read that right, gents. It’s not just cold water that can cause shrinkage. Less sleep is associated with smaller testes, fewer sperm and lower-quality sperm.

Keep that in mind next time you hear a dude in the office bragging about how he gets by on just 4 hours of sleep.

Sleep is essential for men’s health, as this is when most of your testosterone is released. A lack of testosterone can impact everything from your fertility to bone density and muscle mass.

So what are you waiting for? Find the sleep visualization that is right for you and get yourself off to bed.

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