Your target heart rate during exercise depends on your age and how hard you want to work. For moderate-intensity exercise like brisk walking, aim for 50 to 70 percent of your maximum heart rate. For vigorous exercise like running, aim for 70 to 85 percent. Your maximum heart rate is roughly 220 minus your age, which means a 40-year-old has a max of about 180 bpm and a target zone of 90 to 153 bpm during exercise.
Target Heart Rate by Age
The American Heart Association provides a straightforward chart based on age. These ranges cover the full 50 to 85 percent exercise zone:
- Age 20: 100 to 170 bpm (max: 200)
- Age 30: 95 to 162 bpm (max: 190)
- Age 35: 93 to 157 bpm (max: 185)
- Age 40: 90 to 153 bpm (max: 180)
- Age 45: 88 to 149 bpm (max: 175)
- Age 50: 85 to 145 bpm (max: 170)
- Age 55: 83 to 140 bpm (max: 165)
- Age 60: 80 to 136 bpm (max: 160)
- Age 65: 78 to 132 bpm (max: 155)
- Age 70: 75 to 128 bpm (max: 150)
If you’re between ages on the chart, just use the formula: subtract your age from 220 to get your estimated max, then multiply by 0.50 and 0.85 to find the lower and upper ends of your zone. A 52-year-old, for example, has an estimated max of 168 bpm and a target zone of roughly 84 to 143 bpm.
Moderate vs. Vigorous Intensity
The full target zone spans a wide range, so it helps to break it into two tiers. Moderate intensity, the kind you get from a brisk walk, cycling on flat ground, or water aerobics, falls between 50 and 70 percent of your max. This is where most general health benefits live. You should be able to carry on a conversation at this level, though you’ll be breathing harder than normal.
Vigorous intensity, from activities like running, swimming laps, or cycling uphill, pushes you into 70 to 85 percent of your max. You’ll be breathing hard enough that talking in full sentences becomes difficult. If you’re new to exercise, start in the moderate range and work up over several weeks. Jumping straight to vigorous intensity increases injury risk and makes workouts feel miserable, which means you’re less likely to stick with them.
A More Personalized Calculation
The standard “220 minus age” formula gives a rough estimate, but it doesn’t account for your individual fitness level. A more precise approach uses your resting heart rate to calculate what’s called heart rate reserve.
Here’s how it works. First, find your resting heart rate by checking your pulse first thing in the morning before getting out of bed. A normal adult resting heart rate falls between 60 and 100 bpm. People who are very fit often have resting rates in the 40s or 50s, because a stronger heart pumps more blood per beat and doesn’t need to work as hard.
Next, subtract your resting heart rate from your maximum heart rate. That difference is your heart rate reserve. Then multiply that number by the percentage of intensity you want (say, 0.60 for 60 percent), and add your resting heart rate back in. For a 45-year-old with a resting heart rate of 65 bpm who wants to exercise at 60 percent intensity: max is 175, reserve is 110 (175 minus 65), 60 percent of 110 is 66, plus resting heart rate of 65 gives a target of 131 bpm. Compare that to the simpler method (60 percent of 175 equals 105 bpm), and you can see the reserve method produces a meaningfully different, and typically more accurate, number.
This approach is especially useful if your resting heart rate is unusually high or low, because it adjusts the target to reflect your actual cardiovascular starting point rather than just your age.
How to Check Your Heart Rate
The easiest spots to feel your pulse are your wrist and neck. For your wrist, place two fingers (index and middle) on the inside of your opposite wrist, between the bone and the tendon on the thumb side. For your neck, press lightly on either side of your windpipe. Don’t press too hard on the neck, as that can slow your pulse and give an inaccurate reading.
Count the beats for 60 seconds for the most accurate number. If you’re mid-workout and want a quicker check, count for 15 seconds and multiply by four. Fitness trackers and smartwatches with optical heart rate sensors also work reasonably well for steady-state exercise, though they can lag during interval training or be thrown off by sweat and movement.
Why Resting Heart Rate Matters Too
Your resting heart rate is one of the simplest indicators of cardiovascular fitness. A rate at the lower end of the 60 to 100 bpm range generally reflects a heart that pumps efficiently. Very fit athletes often have resting rates closer to 40 bpm. As you get fitter over weeks and months of regular exercise, you’ll likely notice your resting heart rate drop. That’s a sign your heart is getting stronger, even if you don’t feel dramatically different during workouts.
Tracking your resting heart rate over time can also flag when something is off. A sudden jump of 10 or more beats from your baseline, sustained over several days, can signal that you’re overtraining, fighting off an illness, or dehydrated.
When Heart Rate Targets Don’t Apply
Certain medications make standard heart rate zones unreliable. Beta blockers, commonly prescribed for high blood pressure and some heart conditions, keep your heart rate artificially low. You may never reach your calculated target no matter how hard you push. There’s no simple formula to adjust for this because the effect varies from person to person.
If you take a beta blocker or any medication that affects heart rate, a better alternative is the perceived exertion method. Rate how hard the exercise feels on a scale from 6 (no effort at all) to 20 (maximum effort). Most workouts should feel “somewhat hard,” around 12 to 14 on this scale. A practical shortcut: if you can talk but can’t sing, you’re in the moderate zone. If you can only get out a few words at a time, you’re in vigorous territory. If you can’t talk at all, you’re likely working too hard.
Signs You’re Pushing Too Hard
Exercising above 85 percent of your max heart rate doesn’t provide significant additional health benefits for most people and raises the risk of overexertion. Warning signs that you should stop and rest include chest pain, lightheadedness or dizziness, heart palpitations (a fluttering or pounding sensation), shortness of breath that feels disproportionate to the effort, or feeling faint. These symptoms during exercise, particularly if they’re new for you, warrant a conversation with a healthcare provider. A resting heart rate that stays above 100 bpm without an obvious explanation like caffeine, stress, or illness is also worth getting checked.