Why do my muscles tighten up when I sleep?

2021-02-12 - Zana Ali

Sleep helps your muscles recover, detoxifies your organs and rejuvenates your body - With that said, everyone should be looking forward to this ritual right?

Well if you are not waking up well rested and in pain rather than ease, sleep might not be something you are looking forward to, but rather something that keeps you awake and anxious.

We don't want that to happen, so we're here to explain why your muscles might be tightening up and give you some actionable advice on how you can make your muscles relax and recover during night in our 3-part sleep series.

Relationship Between Sleep and Muscle Recovery

Before diving into the correlation between sleep and the muscles, we must understand the two key sleep stages (deep sleep and REM sleep) and the intention of each phase.

Deep Sleep which is the restorative phase for muscle growth and recovery tends to make up anywhere 1-1.5hrs (15-20% of your sleep) on average among adults. It is during this phase your blood pressure drops, muscles relax, and your tissue repairs. Lack of deep sleep may be an indicator of why your body’s muscles tighten up when you sleep.

REM (rapid eye movement) plays an important role in the cognitive function and helps consolidate memory and re-energizing your mind. Although most muscle recovery is associated with deep sleep, the central nervous system (CNS) is transmitting signals to the different parts of your body, thus REM is an important factor that cannot be overlooked in relation to your muscle function and coordination.

As you can tell, both stages are important for your muscles to recover properly. Therefore, you need to make sure you enter these stages enough during your sleeping hours.

Below is an example of how a typical nights sleep looks like. (notice how you enter the deep stage more in the beginning and the REM sleep closer to when you wake up)sleeping-cycles-rem-deep-sleep

So what does this mean for you?

If you don’t enter the deep sleep stage enough, your muscles might be tightening up because they don't fully recover. A sleep tracking device such as the Oura ring will give you insights to your sleep data so that you can better understand the quality of your sleep. 

If you know that your sleep quality is already good and you are getting enough deep sleep, there might be other reasons to why your muscles tighten up.

So… Why does your muscles tighten up when you sleep?

Although it is not easy to pinpoint exactly the reason since each individual case is unique, it could be caused by a couple of main reasons such as: 

Due to inactivity that has weakened your muscles and joint function overtime which can cause soreness from the lightest activities and movements.

Your posture is static during the day for long periods of time. This is even more common nowadays when working remote without proper ergonomic office equipment.

Your body is dehydrated. There is a reason why athletes emphasize staying hydrated, else their muscles would suffer severely and develop cramps. 

Wrong mattress or pillow that does not support your sleep type and body composition.

Arthritis which may limit your mobility and joint function.


Identifying the cause of the issue does not help if you don’t know how to prevent it. Keep reading our 3-part series on sleep to learn what method you can try to help alleviate the muscle tightness and improve your overall sleep quality.

Next Blog: Part 2/3: Sleep and Muscle Recovery Explained

This article is not written by a doctor. At Acies Ideal we are passionate about health, productivity, and balance. We are continuously optimizing these pillars of our lives and are sharing some of our own tips, breakthroughs, and techniques that we have tested and learned from. This may not work for everyone and we recommend consulting with a doctor to get expert and certified advice to diagnose the symptoms and get the right treatment.