Do you know how fast your heart beats when you’re sleeping? If not, it might be time to find out. Countless studies have shown that resting heart rate is a key indicator of longevity. How fast or slow your heart beats during sleep can determine your risk of certain diseases and disorders, all while shedding light on your overall physical health.
Tapping into this knowledge is also important for determining your target heart rate zones, which can guide you to peak athletic performance. Here’s everything you need to know about your sleeping heart rate — plus how to identify and improve it.
What Is Resting Heart Rate?
Heart rate is a metric used to evaluate a person’s cardiovascular health and heart function. While most healthy adults have a resting heart rate between 60 and 80 beats per minute (bpm), factors such as obesity, medications, stress, and your emotional state can increase or decrease your heart rate. Physical fitness levels matter too. In fact, a trained athlete’s resting heart rate may be much lower than average, clocking in somewhere around 40 bpm.
People who exercise often have a lower heart rate because their heart muscle is healthy and strong, meaning it has to pump less to circulate a sufficient amount of blood throughout the body. For people who don’t have a strong heart muscle, their heart has to work extra hard to maintain normal blood flow, resulting in a faster than normal heart rate.
Slow Resting Heart Rates
A slow resting heart rate can mean different things, depending on the circumstances. For example, it sometimes suggests that a person has a healthier heart says Dr. Jason Wasfy at Massachusetts General Hospital Heart Center. “In certain cases, a lower resting heart rate can mean a higher degree of physical fitness, which is associated with reduced rates of cardiac events like heart attacks.”
In other cases, having a slow heart rate could signify something more serious — it all depends on your activity level and age. It’s normal for the elderly to have a lower than average resting heart rate, for example. So what if your resting heart rate is well below 60 bpm, but you’re not an athlete or a senior?
According to the American Heart Association, this could suggest the presence of bradycardia — when a person’s heart rate is lower than it should be. Bradycardia doesn’t always cause symptoms, but when it does, it can cause lightheadedness, weakness, confusion, and lack of energy when exercising. Having these symptoms in addition to a low heart rate may mean it’s time to seek medical advice.
High Resting Heart Rates
In contrast, Wasfy adds that having a high number of beats per minute (above 60 bpm) could increase a person’s risk of cardiac diseases. When the heart has to work harder to pump the same amount of blood throughout the body, it wears out faster. A chronically high heart rate — above 100 bpm — is called tachycardia, and it can be caused by anxiety, fatigue, electrolyte imbalance, overconsumption of alcohol or caffeine, drug use, or other underlying medical conditions.
The negative effects of a fast heart rate were demonstrated in a heart rate study conducted by Copenhagen University Hospital. This study found that a higher resting heart rate (RHR) was directly correlated with health problems and a higher risk of death. Specifically, the risk of mortality increased by 16% for every additional 10 beats per minute.
Sleeping Heart Rate
Understanding your resting and target heart rates can cue you into your night-time heart rate. And when you know how your heart rate varies during sleep, you can gain better insight into disorders that may be affecting your sleep and overall heart health.
Sleeping Heart Rate and Sleep Apnea
One of the most common sleep disorders — and one that’s directly correlated with heart rate — is sleep apnea. This is when a person experiences airway blockages that cause them to involuntarily stop breathing during sleep.
Also called obstructive sleep apnea (OSA), this sleep disorder is most commonly caused by obesity, body mass index, chronic sinusitis, large tonsils or adenoids, large neck circumference, and smoking, says nurse practitioner Kathleen Davis. So how do you know if you have OSA? Davis says that loud snoring, accompanied by restless sleep and daytime fatigue, could indicate the presence of sleep apnea.
The pauses in breath caused by this disorder can last anywhere from a few seconds to a few minutes. People with sleep apnea don’t return to regular breathing gracefully: The transition is often marked by a gasp, snort, or choke, which tends to startle the sleeper (and their partner) awake. These sleep disruptions are why people with sleep apnea often experience daytime tiredness, even after a full night’s sleep.
Fatigue and frustration aside, sleep apnea also affects sleeping heart rate. “When you stop breathing while you sleep, your heart rate drops, and then your involuntary reflexes make you startle into a micro-arousal, which causes your heart rate to accelerate quickly,” says The National Sleep Foundation. In addition to increasing blood pressure, this rapid decrease and increase in heart rate leads to an irregular heart rhythm, or cardiac arrhythmia.
Irregular Heart Rate and Risks
While irregular heartbeats can be caused by a variety of factors, more studies are revealing the direct relationship between irregular heartbeat and atrial fibrillation (AF). One of the most common types of arrhythmia, AF is marked by irregular contractions of the upper heart chambers.
Findings from a sleep apnea study, conducted by the University of Ottawa, suggest that obstructive sleep apnea can increase the risk of atrial fibrillation. The most common symptoms of AF include palpitations, lightheadedness, weakness, fatigue, shortness of breath, and chest pain. Still, many people who have AF may not experience any symptoms at all.
Since AF is associated with stroke, heart failure, and other cardiovascular problems, its link to sleep apnea is pertinent. Such findings also shed light on the importance of learning about sleep disorders like sleep apnea, and its impact on sleeping heart rate.
Current estimates say that over 1 billion people worldwide (and 22 million in America) suffer from sleep apnea, meaning that more people may be at risk of this disorder — and its associated cardiovascular diseases — than realize in waking life.
Understanding and Improving Heart Rate
Having a healthy heart matters — but what can you do to keep your heart rate in a healthy range? Tracking your heart rate with a heart rate monitor is the best way to evaluate your sleeping heart rate. These tools provide you with important heart rate data that can help determine long-term health outcomes.
You can also use the old fashioned method of measuring your pulse rate with your fingertips — just make sure you’ve had ample time to rest after a stressful event or a bout of exercise. Measuring your pulse in cooler, drier temperatures can also ensure a more accurate reading, as heat and humidity can increase heart rate.
Electrocardiograms are another test that can be used to measure the heart. Often administered by a cardiologist, these can be especially useful for people suffering from irregular heart beats, chest pain, heart palpitations, or other heart-related issues. This is a fast, simple method to measure the electrical activity of the heart in its resting state.
When it comes to improving your heart rate and aiming for a healthy range, physical activity is key. Regularly meeting your target heart rate while exercising helps strengthen your heart and improve your aerobic capacity, says Harvard Health Publishing. While this is one of the most effective ways to lower your sleeping heart rate and increase your maximum heart rate, it’s best to proceed with caution.
“Because it’s impossible to maintain a maximum heart rate for more than a few minutes, physiologists have advised setting a percentage of your maximum heart rate as a target during exercise.”
If you’re new to understanding and meeting your target heart rate zones, it’s best to set your target rate at 50% of your maximum target heart rate. Then you can gradually intensify your workout until you reach a higher percentage of your target heart rate.
Improve Your Sleeping Heart Rate, Reduce Your Risks
Sleeping heart rate is an important metric that helps measure the strength of your cardiovascular system. This metric can be influenced by factors like age, weight, and lifestyle habits, and it can determine whether or not you’re more susceptible to heart-related illness.
Knowing your average heart rate can also shed light on the existence of sleep disorders such as sleep apnea and irregular heartbeat, both of which can negatively impact your long-term health. Boosting your exercise efforts and using an activity tracker can offer a more in-depth picture of your heart health to keep your most vital muscle strong.