Napping is supposed to refresh and re-energise us, right?
However, many people wake up from a nap feeling groggy, sluggish, and even more tired than before they laid down.
The science behind naps
When you sleep, your body goes through different stages known as sleep cycles. A full sleep cycle lasts around 90 minutes and is divided into four main stages:
1. Stage 1: Light sleep – This is the transitional phase between being awake and falling asleep. It lasts only a few minutes, and during this time, you can wake up easily.
2. Stage 2: Deeper light sleep – During this stage, your heart rate slows, and your body starts to relax even more. This stage takes up the largest part of the sleep cycle.
3. Stage 3: Deep sleep – This is the stage where your body does most of its recovery, healing, and immune system strengthening.
4. Rapid Eye Movement (REM) Sleep – This is the dreaming stage. Your brain is active, and this is where much of the mental restoration happens.
When you take a nap, depending on how long you sleep, you may wake up in the middle of one of these cycles. Waking up at the wrong point in the sleep cycle, particularly during deep sleep or REM sleep, can leave you feeling groggy and tired. This grogginess is called sleep inertia.
What Is sleep inertia?
Sleep inertia is that heavy, tired feeling you get when you wake up from a nap. It occurs because your body and brain haven’t had time to fully transition from sleep to wakefulness.
If you wake up during the deeper stages of sleep (like deep sleep or REM), it can be particularly difficult to shake off that groggy feeling. Sleep inertia can last anywhere from a few minutes to several hours, depending on how deeply you were sleeping and how much time your body needs to adjust.
How long should you nap?
To avoid feeling more tired after a nap, timing is essential. Short naps that last 10-20 minutes are generally best because they keep you in the lighter stages of sleep. A short nap helps boost your mood, attention, and performance without leaving you feeling groggy. It’s like a quick reset for your brain.
If you nap for 30-60 minutes, you may enter the deeper stages of sleep, which makes waking up more difficult. These naps are behind feeling tired afterwards because you’re likely waking up during deep sleep.
The best nap length, if you have more time, is around 90 minutes. This allows you to complete a full sleep cycle, so you wake up during a lighter stage of sleep, feeling refreshed rather than groggy.
The role of circadian rhythms
Your body’s internal clock, or circadian rhythm, also plays a role in how you feel after napping. Napping too late in the day can confuse your circadian rhythm and make it harder to fall asleep at night, leading to poorer overall sleep quality.
The best time to nap is usually in the early afternoon when your body naturally experiences a dip in energy levels. This aligns with your biological clock and makes it easier to wake up feeling refreshed.
Other factors that affect post-nap tiredness
- Sleep debt: If you’re not getting enough sleep at night, napping during the day might seem like a good solution. However, it’s not a complete fix. You might wake up feeling tired because your body is still trying to catch up on lost sleep, and a short nap may not be enough to meet your needs.
- Sleep environment: Where you nap matters too. If you nap in a noisy or uncomfortable environment, your body may not be able to fully relax, making it harder for you to wake up feeling refreshed. Try to nap in a quiet, comfortable, and dark space if possible.
How to nap without feeling tired
Napping can be a powerful tool for recharging your energy, but only if done right. To avoid waking up feeling more tired, aim for short naps (10-20 minutes) or longer naps that allow for a full sleep cycle (90 minutes). Be mindful of the time of day when you nap and your sleep environment to ensure you wake up feeling refreshed.
If you’re consistently feeling tired after napping, it might be a sign that you need to focus on improving your overall sleep quality at night. The best rest comes from a good night’s sleep.
