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9 Reasons You Feel More Energized on Less Sleep

You may feel more energized on less sleep because of a surge in cortisol and adrenaline or because you’ve become used to the feelings of sleep loss.
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Jamie Zeitzer, PhD, Rise Science Scientific Reviewer
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Woman walking and drinking coffee to feel more energized on less sleep

Why Do I Feel More Energized on Less Sleep?

  • You may feel more energized on less sleep due to a surge in cortisol and adrenaline, your brain’s reward system firing up, or subjectively adapting to sleep loss. 
  • Even if you feel more energized, you’re probably performing worse and your health is taking a hit, too. 
  • The RISE app works out how much sleep you need and helps you catch up on lost sleep to get the sustainable energy, better performance, and health benefits that come with getting enough sleep each night.

Ever had a sleepless night but spent the next day feeling wired and alert? 

You’re not imagining it. But even though you feel more energy, your performance, health, and well-being have probably taken a hit.

Below, we’ll dive into why you feel more energized on less sleep and how the RISE app can help you get more sustainable energy – and all of the benefits of healthy sleep – by getting the right amount of sleep for you.

A Sleep Doctor Explains

A Sleep Doctor Explains

“You may feel more energy on less sleep because your body’s producing more of the stress hormone cortisol. This helps you get through the day, but it’s not a good productivity hack. High cortisol can cause sleep problems, weight gain, and an increased risk of strokes and heart attacks. You’ll have more energy and better health by getting enough sleep.”

Rise Science sleep advisor and medical reviewer Dr. Chester Wu.

Here are the many reasons you may feel energized on less sleep. You might feel the effects of one or more of these depending on how sleep deprived you are. 

Your Cortisol and Adrenaline Levels Increase 

When you don’t get enough sleep, your body produces more of the alertness-boosting hormones cortisol and adrenaline to get you through the day.

Research shows pulling an all-nighter significantly increases cortisol, but even sleeping for 5.5 hours can increase cortisol levels the next evening.

This isn’t a good thing, though. 

These hormones give you a false sense of energy and they can make it hard to sleep at night as you’re stuck in fight-or-flight mode, leading to even more sleep loss. 

Plus, high cortisol levels can cause: 

Your Brain’s Reward System Fires Up 

Research shows sleep loss increases reactivity in your brain’s reward system. You may react better to both positive and negative stimuli, or you may experience giddiness or euphoria, making you feel better when you sleep less. 

Sleep loss can even improve the moods of those with depression. 

Research shows an all-nighter can improve depressive symptoms in 40% to 60% of cases. But these improvements disappear when people get more sleep. 

Heads-up: Speak to a healthcare provider if you’re experiencing mental health problems like depression. Don’t try sleep restriction without supervision. 

Beyond your mood, your brain becomes more sensitive and amped up the longer you’ve been awake. One study found the excitability of your frontal cortex (a part of your brain) increases with time awake and decreases when you get more sleep.

So your brain may be working in overdrive. Sleep deprivation is linked to hyperactivity and impulsivity, and to ADHD and symptoms that mimic ADHD, which could make you feel like you have more energy.

We asked one of our sleep advisors, Dr. Jamie Zeitzer, co-director of the Center for Sleep and Circadian Sciences at Stanford University, why some people feel more energized on less sleep. 

“This paradoxical response occurs in some people possibly as a consequence of the brain trying to keep you awake through abnormal mechanisms.” 

This extra energy isn’t healthy sustainable energy, though.

As Dr. Zeitzer puts it, “it could be viewed similarly to a manic state.”

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Your Dopamine Levels Increase 

Sleeping less may also affect dopamine, the “feel-good” hormone.

A 2023 mouse study found sleep loss enhances dopamine release in the brain.

In sleep deprived mice, this led to hyperactivity, aggression, fewer depressive-like behaviors, and more social and sexual behavior.  

More research needs to be done to determine if this also happens in humans and contributes to the tired-but-wired feeling you sometimes get after little sleep.

You Subjectively Adapt to Sleep Loss 

Our brains are good at tricking us. When we don’t get enough sleep, we can subjectively adapt to some of the effects of chronic sleep deprivation. 

We feel fine on less sleep, but we’re not really doing fine at all.

One study found participants’ performance on cognitive tests got significantly worse the more sleep deprived they became. But their ratings of sleepiness only increased slightly at first and then evened out. 

The study stated, “Sleepiness ratings suggest that subjects were largely unaware of these increasing cognitive deficits, which may explain why the impact of chronic sleep restriction on waking cognitive functions is often assumed to be benign.” 

Another sleep study found people who said they got enough sleep slept more than three hours longer when they got the chance — meaning they were probably sleep deprived and didn’t know. 

And you might simply be missing the signs of sleep deprivation.

It’s not just low energy — sleep loss can cause everything from weight gain to acne, digestive issues to mental exhaustion. It’s easy to blame a bad diet or stress over poor sleep for these symptoms. 

You Do Energy-Boosting Things When You Get Less Sleep 

It might not be your reduced sleep time that’s making you feel more energized. 

When you know you’ve had less sleep, you might reach for stimulants like an extra cup of coffee, energy drink, or sugary snack to help you function on no sleep. Or maybe you do something healthy like getting out for a run in morning sunlight.

These things could be making you feel more energized, despite the lack of sleep.

Research from 2016 states that people who think they do fine on little sleep may actually need environmental stimulation to stay awake and underestimate how sleepy they really are. 

And 2023 research highlights how caffeine and alcohol can both impact your sleep. You might use caffeine to perk you up and alcohol to make you drowsy and not realize how poor your sleep is with this self-medication. 

You’re in Sync With Your Circadian Rhythm 

Your circadian rhythm is your roughly 24-hour body clock. When you’re out of sync, your energy levels will be lower. 

You can get out of sync by: 

  • Doing shift work 
  • Having an irregular sleep schedule 
  • Ignoring your chronotype (like a night owl trying to wake up early)

You may be sleeping less, but now be more in sync with your circadian rhythm, which is boosting your energy levels. 

Maybe you were hitting snooze on weekends and waking up during a natural dip in energy, or now you’re honoring your night owl ways or have a regular sleep routine.

Heads-up: Your energy levels rise and fall predictably throughout the day. So you’ll have peaks in energy (usually mid-morning and early evening), even on less sleep.

RISE can predict the timing of your circadian rhythm each day, so you can see when your energy levels are expected to rise and fall. 

RISE users say this helps them plan their day. 

“I love the option to view your energy cycles throughout the day — I can plan more important tasks just when my energy is at its peak.” Read the review

RISE app screenshot showing your energy dip and peak times
The RISE app can predict your daily circadian rhythm.

RISE users on iOS 1.202 and above can see their circadian rhythm on the Energy screen here

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You’ve Caught Up On Sleep 

Let’s say you need eight hours of sleep, but have been regularly getting six hours. Then you spend several nights catching up on sleep with nine hours of sleep or more. 

Now you’re back to eight hours — so you’re sleeping less — and you feel more energized. 

You’ll feel better for catching up on lost sleep, but another reason you feel more energized could be sleep inertia. This is the groggy feeling you get when you first wake up. 

Sleep inertia can feel worse and last longer when you’re sleep deprived. Once you’re caught up on sleep and back on your normal sleep pattern, you may feel less sleep inertia and therefore more energized each morning, even though you’re technically getting less sleep than when you were catching up. 

RISE works out how much sleep debt you have (the sleep you owe your body), so you can see whether you need to catch up. 

RISE app screenshot showing how much sleep debt you have
The RISE app calculates your sleep debt.

RISE users on iOS 1.202 and above can view their sleep debt here.

You’ve Improved Your Sleep Hygiene 

Sleep hygiene is the set of habits that can help you get better sleep. If you’ve improved them recently, you may be sleeping less or spending less time awake in bed (which is easy to mistake for time spent asleep), but feeling better. 

Good sleep hygiene helps you fall asleep faster and wake up less often, so your sleep is less broken (which is more restorative) and you spend less time in bed getting the sleep you need. 

So you may not be sleeping less exactly, but sleeping more efficiently. This means you’re spending less time in bed getting the (same amount of) sleep you need.

Beyond daytime sleepiness, your mood might be better, too. Research shows sleep interruptions impact your mood more than getting the same amount of sleep in less time.

As better sleep hygiene can lead to less restless sleep, you may feel like you got a good night’s sleep, which can make you feel better about your sleep. Research from 2021 found how people feel about their sleep has a bigger impact on fatigue than sleep duration. 

Expert tip: Follow RISE’s 20+ sleep hygiene recommendations each day to more easily get enough sleep and more energy. 

RISE app screenshot showing your sleep hygiene reminders
The RISE app can guide you through 20+ sleep hygiene habits.

RISE users on iOS 1.202 and above can set up their 20+ in-app habit notifications here

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You’ve Fixed an Energy Drain 

Sleep isn’t the only thing that affects your energy levels. Diet, physical activity, stress, health conditions, medications, and hormones all play a role in how you feel each day. 

So you may feel more energized due to something else entirely — like coming off medication, starting a workout plan, or working on a cortisol-spiking presentation.

Or, back to sleep for a second, you might have got treatment for a sleep disorder, like sleep apnea

All of these factors can also influence your sleep hygiene, contributing to less time awake in bed, so you feel like you’re sleeping less, but enjoying more energy. 

Sleep Cycles Have Nothing to Do With It

You’ve probably heard that waking up at the end of a sleep cycle can make you feel more energized than waking up midway through a stage of sleep. This lends itself to the theory that you’re sleeping less, but waking up at the end of a sleep cycle and feeling better for it.

Unfortunately, it’s not that clear-cut. 

Research is mixed on whether waking up in deep sleep compared to rapid-eye-movement sleep (REM sleep) or light sleep will make you feel groggier. And even if it does, wearable devices aren’t that accurate at tracking sleep cycles, so you can’t really tell when you’re waking up.

Plus, sleep cycles look different for everyone and can change from night to night and throughout the night. So you time your sleep to match sleep cycles anyway.

Short Sleep Syndrome Has Nothing to Do With It 

Some people genetically need very little sleep. This is known as short sleep syndrome. 

This is very unlikely to be the reason you feel more energy on less sleep. 

It’s hard to oversleep and get more sleep than you need. So those who are natural short sleepers wouldn’t have been getting more sleep to begin with — it’s a lifelong trait for them. 

You can learn more about short sleep syndrome here.

Expert tip: We all need a different amount of sleep. We looked at how much sleep 1.95 million RISE users aged 24 and older need and found it ranged from five hours to 11 hours 30 minutes. 

RISE can tell you how much sleep you need exactly.

The RISE app can tell you how  much sleep you need.
How much sleep RISE users need.

RISE users on iOS 1.202 and above can view their sleep need here

You Can Feel Even Better With Enough Sleep 

You may feel more energized on less sleep, but this may be short term. Plus, your performance will probably be impaired, and you’ll be at risk of the negative side effects of sleep deprivation — which includes a lowered immune system, obesity, type 2 diabetes, and heart disease. 

There is a way to get more energy and better performance and overall health, and that’s by getting enough sleep. 

Check RISE to find out how much sleep you need, catch up on sleep debt if needed, and then follow the app’s 20+ healthy sleep habit recommendations each day to make falling and staying asleep easier. 

Good sleep is the ultimate energy boost and it doesn’t take long — 80% of RISE users feel more energy within five days.


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Rise is the only app that unlocks the real-world benefits of better sleep.

Instead of just promising a better night, we use 100 years of sleep science to help you pay down sleep debt and take advantage of your circadian rhythm to be your best.

Over the past decade, we've helped professional athletes, startups, and Fortune 500s improve their sleep to measurably win more in the real-world scenarios that matter most.

Rise Science is backed by True Ventures, Freestyle Capital, and High Alpha; investors behind category winners Fitbit, Peloton, and Salesforce Marketing Cloud.

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