What Is a Normal Sleeping Heart Rate?
8 min read
Last Modified 9 January 2024 First Added 19 December 2023
Age, gender, fitness levels, and health can all affect your sleeping heart rate. And when viewed the opposite way, the number of beats per minute (BPM) you get while sleeping can provide insights into all of those factors too. Here, we’ll explore what constitutes a healthy rate, when to be concerned, and the factors that impact how hard your heart has to work each night.
Before we start, though, it’s important to know that resting and sleeping heart rates aren’t the same thing. Typically, your heart will beat slower while you sleep than it would when you’re awake, no matter how chilled out you feel. That’s because when you reach deep sleep, also known as NREM3, your body goes into a slowed-down mode of restoration that’s not possible while our minds are active. At this point, your sleeping heart rate can drop up to 20% below your resting levels.
On the other hand, nightmares and dreams, which happen during what’s called REM sleep, affect our sleeping heart rate in the opposite direction. Think about when you last jolted awake from a nightmare, did you feel relaxed, or did you feel like your breathing and heart were working hard? That’s totally normal. In the REM phase, it’s not uncommon for your heart rate to be as high as it would be during light exercise.
Just like with your resting heart rate, the number of times your heart beats each minute during sleep can provide insights into your overall health. Take a look at this quote from a study by the Scandinavian Journal of Clinical and Laboratory Investigation, published on the US National Library of Medicine.
Assessment of heart rate has been used for millennia as a marker of health. Several studies have indicated that low resting heart rate (RHR) is associated with health and longevity, and conversely, a high resting heart to be associated with disease and adverse events.
Additionally, it’s tricky to get accurate readings of heart rate while awake because they’re so responsive to our body’s movement and exertion, as well as other factors like stress and anxiety. Monitoring your sleeping heart rate creates a fairer test because you are at your most relaxed and less prone to factors which might skew the reading.
To identify what your sleeping heart rate should be, you first need to know your resting heart rate.
The average resting heart rate for healthy adults is 60-100 bpm. However, many factors can affect your heart rate. Males tend to have a lower heart rate than females as their heart has a greater mass.
Additionally, athletes and physically fit individuals can have a resting heart rate as low as 30 bpm. This is because athletes’ hearts are well-conditioned to pump blood efficiently throughout the body.
To work out your heart rate, follow NHS guidelines or get your figure from a fitness watch or similar piece of smart tech.
During sleep, your heart rate drops roughly between 20-30% of your resting heart rate. Dr Lawrence Epstein, an associate physician at Harvard-affiliated Brigham and Women’s Hospital, states:
“During sleep, the stimulation of your nervous system is reduced and most of your body processes slow down.”
Therefore, if your resting heart rate is 60, your sleeping heart rate should be 40-50 bpm. However, this can vary by age. For example, 1-2 year-olds have an average sleeping heart rate of 80-130 bpm.
While sleeping and resting heart rates are best considered in relation to your active heart rate, rather than following a strict guide, here’s a very general breakdown of resting heart rates by age, from MedlinePlus.
Unsafe heart rates are typically those which are too fast. If your sleeping heart rate is above 100, this is a cause for concern.
When your heart rate is above 100 bpm, it is called tachycardia. But it’s not always a cause for concern. For example, if you’re exercising, you’ll be in a state of tachycardia that’s totally normal and expected.
However, if you feel like your heart rate is high outside of circumstances which require it to be so – such as a prolonged period of sleep – speak to your GP as soon as possible. Dr. Dongfeng Zhang, the primary investigator from the Medical College of Qingdao University in Shandong, China, emphasizes the importance of monitoring resting heart rate:
Available evidence does not fully establish resting heart rate as a risk factor, but there is no doubt that elevated resting heart rate serves as a marker of poor health status.
Within just 5 minutes of falling asleep, your heart rate decreases. During light sleep, your heart rate will be at its average resting rate. Throughout light sleep, you will enter muscle relaxation and your body temperature will drop.
This is your body’s way of preparing you for a deeper sleep. Expect your heart rate to be at its lowest during the deep sleep stage, which can go 20-30% below your resting heart rate.
However, as referenced earlier, entering the REM stage (rapid eye movement) can trigger an increase, especially if you are dreaming. For a deeper understanding of your dreams, check out our article on what dreams mean and why we have them.
Various factors can influence your heart rate during sleep, impacting the quality and restorative nature of your nightly rest.
As mentioned, exercise is one of the factors that can impact your sleeping heart rate. And to truly understand your heart rate, and recognise what’s causing changes to your cardiovascular system while you sleep, you may want to take note of how many beats per minute you reach during exercise. Let’s explore.
When working out, your heart works harder to supply oxygen to the rest of your body. The recommended heart rate depends on the intensity of the workout.
For moderate-intensity activities, you want to aim for 64% and 76% of your maximum heart rate. For more vigorous activities, your heart rate should be between 77% and 93%.
To work out your maximum heart rate, subtract 220 from your age. For example, if you’re 50 years old, you would first calculate 220-50, which is 170 bpm and then apply the percentage provided above. Here are some examples for a 50-year-old:
You can follow the same process to work out your maximum heart rate for more intense exercises. Again, subtract your age from 220. For a 35-year-old, you would calculate 220-35 and then apply the percentages for more intense activity. This would look like this:
So, understanding the nuances of heart rate is crucial for optimising your well-being. From daily fluctuations to how it varies during sleep, our heart rate serves as a barometer of health. For more support with a good night’s rest, explore our article on how to sleep better at night.