Your heart rate is the number of times your heart beats per minute. For most adults sitting or lying down calmly, a normal resting heart rate falls between 60 and 100 beats per minute (bpm), with the average landing around 72 bpm. That number shifts throughout the day based on what you’re doing, how you’re feeling, and even whether you’re asleep or awake.
What Controls Your Heart Rate
A small cluster of cells in the upper right chamber of your heart acts as a natural pacemaker, sending electrical signals that trigger each heartbeat. Your nervous system adjusts how fast or slow those signals fire depending on what your body needs. When you’re exercising, stressed, or startled, your “fight or flight” system speeds things up. When you’re resting or digesting a meal, your “rest and digest” system slows things down. This is why your heart rate can swing from 50 bpm on the couch to over 150 during a hard run, all within the same hour.
Average Resting Heart Rate by Age and Sex
Heart rate changes dramatically from birth through adulthood. Infants average about 129 bpm, which drops to around 96 bpm by age 5, then settles near 78 bpm in early adolescence. By adulthood, the average plateaus at roughly 72 bpm and stays remarkably stable through old age. CDC data shows adult men average 71 bpm across every age group from 20 to 80+, while adult women average 74 bpm, running slightly higher at younger ages (76 bpm in their 20s and 30s) before settling to 73 bpm after 40.
Girls and boys show this same pattern. Female infants average 130 bpm and female teens 79 bpm, while male infants average 128 bpm and male teens 72 bpm. The sex-based difference of a few beats per minute persists throughout life.
Why Athletes Have Lower Heart Rates
Endurance training physically enlarges the heart’s chambers, allowing them to hold and pump more blood with each beat. Because each contraction pushes out a larger volume, the heart doesn’t need to beat as often to deliver the same amount of oxygen. Trained endurance athletes can have resting heart rates below 40 bpm, a number that would be considered abnormally slow in a sedentary person but is perfectly healthy in someone who runs, cycles, or swims regularly. During maximum effort, a young athlete’s heart rate can exceed 200 bpm.
What Happens to Your Heart Rate During Sleep
Your heart rate doesn’t stay flat overnight. During deep sleep, it drops to about 20% to 30% below your normal resting rate. If you typically rest at 70 bpm, that means your heart could slow to the high 40s or low 50s during your deepest sleep cycles. During REM sleep, the stage where vivid dreams occur, your heart rate becomes more variable. A stressful or active dream can push your heart rate up as if you were awake and moving.
What Raises Your Resting Heart Rate
Several everyday factors push your resting heart rate higher. Dehydration forces the heart to work harder to circulate a reduced blood volume. Caffeine and nicotine both stimulate the nervous system. Emotional stress, anxiety, fever, and heat exposure all raise the baseline. Some medications, particularly decongestants and certain asthma drugs, can also increase it. Even body position matters: your heart rate is slightly higher when standing than when lying down, which is why proper measurement calls for sitting quietly first.
A consistently elevated resting heart rate carries real health implications. Large-scale studies show that every 10 bpm increase in resting heart rate is associated with roughly a 9% increase in the risk of dying from any cause. Even within-person changes as small as about 3 bpm over time have been linked to measurably higher risk. A resting heart rate that creeps upward over the years can be an early signal worth paying attention to.
How to Measure Your Heart Rate
The simplest method requires nothing but your fingers and a clock. Sit quietly for a few minutes first, then turn one hand palm up. Place the tips of your index and middle fingers on the inside of your opposite wrist, between the bone and the tendon on the thumb side. Press lightly until you feel the pulse, then count beats for 60 seconds. You can also count for 15 seconds and multiply by four, though the full 60 seconds is more accurate.
You can also check at your neck by placing two fingertips in the groove beside your windpipe. Press gently. Don’t press hard, as that can actually slow blood flow, and never press both sides of your neck at the same time, which can cause dizziness or fainting. Wearable fitness trackers and smartwatches use optical sensors to estimate heart rate continuously, which is useful for spotting trends over days and weeks even if individual readings aren’t perfectly precise.
Target Heart Rate During Exercise
Your maximum heart rate is roughly estimated by subtracting your age from 220. A 40-year-old, for example, has an estimated max of 180 bpm. From there, exercise intensity is measured as a percentage of that max. Moderate exercise, like brisk walking or easy cycling, falls between 50% and 70% of your maximum. For the 40-year-old, that’s 90 to 126 bpm. Vigorous exercise, like running or high-intensity intervals, targets 70% to 85%, or 126 to 153 bpm.
The general guideline is to accumulate either 150 minutes per week at moderate intensity or 75 minutes per week at vigorous intensity. These are targets to build toward gradually, not starting points.
When Heart Rate Signals a Problem
A resting heart rate consistently above 100 bpm is called tachycardia. A rate consistently below 60 bpm is called bradycardia, though as noted, this is normal for fit individuals. Some cardiologists have proposed tighter thresholds, with rates above 90 or below 50 warranting closer attention in sedentary people.
The number alone isn’t always the concern. What matters more is whether an unusual heart rate comes with symptoms: feeling your heart pounding or fluttering, lightheadedness, dizziness, chest pain, shortness of breath, or near-fainting. Any of these paired with a heart rate that feels too fast, too slow, or irregular deserves prompt medical attention.