A healthy adult heart beats 60 to 100 times per minute at rest. That number shifts depending on your age, fitness level, what you’re doing, and even whether you’re asleep or awake. Here’s what shapes your heart rate and what the numbers actually mean.
Resting Heart Rate by Age
The 60-to-100 range applies to adults and children over 10. Younger children and babies have significantly faster hearts. A newborn’s heart can beat anywhere from 85 to 205 times per minute while awake, because a smaller heart pumps less blood per beat and needs to compensate with speed.
Here’s how resting heart rate changes with age:
- Newborn to 3 months: 85 to 205 bpm awake, 80 to 160 bpm asleep
- 3 months to 2 years: 100 to 190 bpm awake, 75 to 160 bpm asleep
- 2 to 10 years: 60 to 140 bpm awake, 60 to 90 bpm asleep
- Over 10 years and adults: 60 to 100 bpm awake, 50 to 90 bpm asleep
By the time a child reaches about 10, their heart rate settles into the adult range and stays there for the rest of their life, barring other health changes.
How Sleep Changes Your Heart Rate
Your heart slows down considerably when you sleep, typically running 20% to 30% below your daytime resting rate. If your waking resting heart rate is 70 bpm, you might drop into the low 50s overnight. The deepest phase of non-REM sleep is when your heart rate and blood pressure dip the lowest. During REM sleep (when you dream), your heart rate rises again and can fluctuate more, sometimes approaching waking levels.
What Counts as Too Fast or Too Slow
A resting heart rate consistently above 100 bpm is considered tachycardia. Below 60 bpm is technically bradycardia, though many healthy people, especially those who exercise regularly, sit comfortably in the 50s without any problems. Population studies often use 50 bpm as a more practical cutoff for concern.
Very fit endurance athletes can have resting heart rates near 40 bpm. Their hearts have adapted to pump more blood per beat, so fewer beats accomplish the same work. This is a sign of cardiovascular efficiency, not a problem.
Context matters more than any single number. A heart rate of 55 bpm in someone who runs daily is normal. The same rate in someone who is dizzy, fatigued, or lightheaded warrants attention.
What Raises or Lowers Your Heart Rate
Plenty of everyday factors push your heart rate up or down. Caffeine, nicotine, and alcohol all increase heart rate through different mechanisms. Caffeine and nicotine stimulate your nervous system directly. Alcohol promotes a stress response that speeds the heart and can disrupt its rhythm. Cocaine and amphetamines cause a surge of stress hormones that can push heart rate dangerously high.
On the other side, certain medications deliberately slow your heart. Beta-blockers, commonly prescribed for high blood pressure and anxiety, suppress the electrical signals that set your heart’s pace. Some medications used for memory problems in older adults can also slow heart rate as a side effect.
Other factors that raise resting heart rate include dehydration, fever, stress, and anxiety. High altitude bumps heart rate up by 10% to 30% as your body works harder to deliver oxygen with thinner air. Even standing up after sitting for a while temporarily increases your rate by 10 to 15 beats.
Your Heart Rate During Exercise
During physical activity, your heart rate climbs well above its resting level. A rough estimate of your maximum heart rate is 220 minus your age. For a 40-year-old, that’s about 180 bpm.
The American Heart Association breaks exercise intensity into two broad zones. Moderate-intensity activity (brisk walking, casual cycling) puts you at 50% to 70% of your max. Vigorous activity (running, competitive sports) pushes you to 70% to 85%. For that same 40-year-old, moderate exercise would mean a heart rate of roughly 90 to 126 bpm, while vigorous exercise would land between 126 and 153 bpm.
More detailed training frameworks divide effort into five zones, ranging from a light warmup pace at 50% to 60% of max all the way up to all-out sprints at 90% to 100%. Most people doing regular exercise for health benefits spend most of their time in zones 2 and 3, between 60% and 80% of their maximum.
How to Check Your Heart Rate
The simplest method is a manual pulse check. Place two fingers (not your thumb, which has its own pulse) on the inside of your wrist, between the bone and the tendon on the thumb side. You can also feel your pulse on either side of your neck, just beside your windpipe.
Once you find a steady beat, count for a full 60 seconds. A quicker approach is to count for 15 seconds and multiply by four, though the full minute gives a more accurate reading. Take your resting measurement after sitting quietly for at least five minutes, ideally in the morning before coffee or exercise.
Wearable fitness trackers and smartwatches use optical sensors to estimate heart rate continuously. They’re generally reliable for resting measurements and trends over time, though they can be less accurate during high-intensity exercise or if the band isn’t snug against your skin.
What Your Resting Heart Rate Tells You
A lower resting heart rate generally reflects better cardiovascular fitness. As your heart gets stronger through regular exercise, it pumps more blood per beat and doesn’t need to beat as often. Tracking your resting heart rate over weeks or months can be a useful way to gauge whether your fitness is improving.
A sudden, unexplained increase in resting heart rate, say 10 or more beats above your personal baseline lasting several days, can signal overtraining, illness, poor sleep, or elevated stress. Many endurance athletes use morning heart rate as an early warning system for these issues. If your resting heart rate stays elevated without an obvious cause like caffeine or a stressful week, it’s worth paying attention to what else your body might be telling you.