A heart rate of 57 beats per minute is just slightly below the standard “normal” range of 60 to 100 bpm for adults, and in most cases it’s perfectly fine. The medical term for a heart rate under 60 is bradycardia, but that label alone doesn’t mean something is wrong. What matters far more than the number itself is whether you feel okay.
Why 57 BPM Is Usually Normal
The 60-to-100 range is a general guideline, not a hard cutoff. Plenty of healthy adults sit comfortably in the mid-to-upper 50s without any issues. If you exercise regularly, a resting heart rate in the 50s is expected. Exercise strengthens the heart muscle so it can pump more blood with each beat. That means the heart doesn’t need to beat as often to deliver oxygen to your body, which naturally lowers your resting rate. Endurance athletes sometimes dip below 40 bpm.
Even if you’re not particularly athletic, genetics, body composition, and overall fitness can all push your resting heart rate into the 50s. During sleep, heart rates of 50 to 75 bpm are typical for healthy adults, and rates as low as 40 can be normal depending on the person. So if you noticed 57 on a fitness tracker overnight or while relaxing on the couch, that reading is well within what’s expected.
When a Heart Rate in the 50s Needs Attention
A heart rate of 57 becomes a concern when it’s paired with symptoms that suggest your brain and organs aren’t getting enough blood flow. Those symptoms include:
- Dizziness or lightheadedness
- Fainting or near-fainting
- Unusual fatigue, especially during physical activity
- Shortness of breath
- Chest pain
- Confusion or trouble focusing
If you have none of these symptoms, a heart rate of 57 generally doesn’t require any treatment. The American Heart Association’s clinical guidelines for bradycardia focus on rates that are causing measurable problems like low blood pressure, signs of shock, or altered mental status, and those situations typically involve rates well below the 50s.
Common Causes of a Slower Heart Rate
Beyond physical fitness, several other factors can bring your heart rate into the 50s. Certain medications, particularly those prescribed for high blood pressure or heart conditions, are designed to slow the heart down. If you recently started a new medication and noticed your rate dropping, that’s likely the intended effect, but it’s worth mentioning to your prescriber if you feel sluggish or dizzy.
An underactive thyroid can also slow the heart. If a lower heart rate is new for you and comes with other changes like weight gain, feeling cold, or low energy, a simple blood test can check your thyroid function. Less commonly, issues with the heart’s electrical system or damage from prior heart disease can slow the rate, but these conditions usually produce noticeable symptoms rather than a quiet reading of 57.
Sleep apnea is another factor. Repeated pauses in breathing during sleep can alter heart rhythm and rate. If you snore heavily, wake up feeling unrested, or a partner has noticed you stop breathing at night, that connection is worth exploring.
What Testing Looks Like
If your doctor wants to investigate a slower heart rate, the process is straightforward and noninvasive. The primary tool is an electrocardiogram (ECG), which records your heart’s electrical activity through sensors placed on your skin. It takes a few minutes and shows whether the electrical signals controlling your heartbeat are traveling through the heart normally.
Because a single ECG only captures a snapshot, your doctor may ask you to wear a portable monitor. A Holter monitor records your heart rhythm continuously for a day or two. An event recorder works similarly but can be worn for up to 30 days, capturing episodes that come and go. Blood work is common too, checking thyroid levels, potassium, and other markers that influence heart rate. In some cases, a stress test on a treadmill or stationary bike helps reveal rhythm problems that only appear during exertion.
For someone sitting at 57 bpm with no symptoms, most of this testing isn’t necessary. It’s typically reserved for people whose rates are consistently low and accompanied by the warning signs listed above.
The Bottom Line on 57 BPM
A resting heart rate of 57 sits just below the textbook range, but it falls squarely within what’s normal for many adults, especially those who are physically active or measuring during rest or sleep. If you feel fine, have good energy, and aren’t experiencing dizziness or fainting, 57 is a sign of a heart that’s working efficiently rather than one that’s struggling. The number only becomes meaningful when your body tells you something is off.