For most people, a good workout heart rate falls between 50% and 85% of your maximum heart rate, depending on how intense the exercise is. Moderate activities like brisk walking or cycling should put you at 50% to 70% of your max, while vigorous exercise like running or high-intensity intervals should land between 70% and 85%. Your maximum heart rate is roughly 220 minus your age, which means the actual beats-per-minute targets shift as you get older.
Target Heart Rate by Age
The simplest way to find your range is to start with the formula: 220 minus your age equals your estimated maximum heart rate. From there, multiply by the percentages for the intensity you’re going for. Here’s what that looks like in practice:
- Age 20: 100 to 170 bpm
- Age 30: 95 to 162 bpm
- Age 40: 90 to 153 bpm
- Age 50: 85 to 145 bpm
- Age 60: 80 to 136 bpm
- Age 70: 75 to 128 bpm
The lower end of each range represents moderate effort, the upper end represents vigorous effort. If you’re just starting an exercise routine, staying in the lower half gives you a solid workout without overdoing it. As your fitness improves, you can push into the upper range during harder sessions.
How Accurate Is the 220-Minus-Age Formula?
The 220-minus-age formula has been used for decades, but it can be off by 10 to 12 beats per minute in either direction. A slightly more refined version, sometimes called the Tanaka equation, calculates max heart rate as 208 minus 0.7 times your age. For a 40-year-old, that gives 180 bpm instead of the 180 from the standard formula (they converge at that age), but the gap widens at younger and older ages.
Research on recreational marathon runners found that both formulas overestimated max heart rate by about 5 bpm in women and the standard formula underestimated it by about 3 bpm in men. These aren’t huge errors, but they mean the zones you calculate are estimates. If a workout feels too easy or impossibly hard at your “target” number, trust your body over the math.
A More Personalized Approach: Heart Rate Reserve
The standard percentage method treats everyone with the same max heart rate as identical, but two 40-year-olds can have very different fitness levels. Someone with a resting heart rate of 55 bpm has more cardiovascular headroom than someone resting at 80 bpm. The Karvonen method accounts for this by using your heart rate reserve, which is simply your max heart rate minus your resting heart rate.
To use it: subtract your resting heart rate from your estimated max, multiply by your target percentage (say, 60% to 80% for a solid workout), then add your resting heart rate back. For a 40-year-old with a resting heart rate of 60 and an estimated max of 180, the reserve is 120. At 60%, the target becomes 72 plus 60, or 132 bpm. At 80%, it’s 96 plus 60, or 156 bpm. This method tends to be more accurate than the simpler percentage-of-max approach because it factors in your individual baseline fitness.
To get your resting heart rate, check your pulse first thing in the morning before you get out of bed. Count for a full 60 seconds on a few different days and average the results.
Moderate vs. Vigorous Intensity
Not every workout needs to push you to the upper end of your range. The American Heart Association breaks exercise into two main tiers: moderate intensity at 50% to 70% of max, and vigorous intensity at 70% to 85%. Both provide real cardiovascular benefits, and most fitness guidelines recommend a mix of the two throughout your week.
Moderate intensity feels like effort but still lets you carry on a conversation. Think brisk walking, casual cycling, or water aerobics. Vigorous intensity makes talking difficult. You can get out a few words between breaths, but holding a full conversation isn’t comfortable. Running, swimming laps, and high-intensity interval training all fall here.
If you don’t have a heart rate monitor, the “talk test” is a surprisingly reliable shortcut. If you can chat easily, you’re in the moderate zone. If you can only manage short phrases, you’ve crossed into vigorous. If you can’t speak at all, you’re likely above 85% and pushing beyond what most people need for fitness gains.
The “Fat Burning Zone” Explained
Many cardio machines label the lower-intensity range (roughly 50% to 70% of max) the “fat burning zone,” which is technically true but misleading. At lower intensities, your body does rely more heavily on fat as fuel. As intensity climbs, your muscles shift toward burning carbohydrates because they can convert sugar to energy faster.
Here’s the catch: higher-intensity exercise burns more total calories per minute. So even though a smaller percentage of those calories come from fat, the overall calorie burn is greater, and the effect on long-term fat loss is typically better. You’re still burning some fat at higher intensities; you’re just also burning more of everything else. The best workout for losing body fat is the one you’ll actually do consistently, regardless of which “zone” the treadmill display highlights.
When Heart Rate Targets Don’t Apply
Certain medications change the equation entirely. Beta blockers, commonly prescribed for high blood pressure and some heart conditions, slow your heart rate and can make it physically impossible to reach your standard target no matter how hard you push. There’s no simple formula to adjust for this, because the effect varies from person to person and depends on the dose.
If you take a beta blocker or similar medication, perceived exertion becomes your best guide. The Borg Rating of Perceived Exertion Scale runs from 6 (no effort) to 20 (maximum effort). Most workouts should feel “somewhat hard,” around 13 to 14 on that scale. You’re working, you’re sweating, but you could keep going. If you can’t talk at all, back off.
Pregnancy also changes heart rate responses in unpredictable ways. Some pregnant women see a blunted heart rate response to exercise, while others see normal patterns. Because of this variability, the American College of Obstetricians and Gynecologists recommends using perceived exertion and the talk test rather than chasing a specific number. Moderate-intensity exercise during pregnancy should feel “somewhat hard” while still allowing you to hold a conversation.
What Your Recovery Heart Rate Tells You
How quickly your heart rate drops after you stop exercising is one of the best indicators of cardiovascular fitness, and it’s easy to track over time. A healthy heart rate recovery is a drop of at least 18 beats per minute within the first minute after stopping exercise. The bigger the drop, the better your heart’s ability to shift gears between stress and rest.
To measure it, note your heart rate the moment you finish your hardest effort, then check again after one minute of standing or slow walking. If the drop is consistently below 12 bpm, it may signal that your cardiovascular system isn’t recovering efficiently. Tracking this number over weeks and months gives you a practical way to see whether your fitness is actually improving, independent of how fast you run or how much you lift.
How to Check Your Heart Rate During Exercise
Wrist-based fitness trackers and chest strap monitors are the most common tools. Chest straps tend to be more accurate during intense or high-movement exercises because wrist sensors can lose contact with your skin when you sweat or move your arms rapidly. For steady-state cardio like cycling or elliptical work, wrist monitors are generally reliable enough.
If you don’t have a device, press two fingers against the side of your neck or the inside of your wrist, count the beats for 15 seconds, and multiply by four. This is harder to do mid-sprint, but it works well during rest intervals or immediately after you stop moving. Pausing briefly during a workout to take a manual count can help you calibrate your sense of effort so that over time, you learn what different heart rate zones feel like without needing to check a number.