A good heart rate for working out falls between 50% and 85% of your maximum heart rate, depending on how hard you want to push. For moderate exercise like brisk walking or easy cycling, aim for 50% to 70% of your max. For vigorous exercise like running or high-intensity intervals, aim for 70% to 85%. Where you fall in that range depends on your fitness goals, your current conditioning, and the type of workout you’re doing.
How to Find Your Maximum Heart Rate
Everything starts with estimating your maximum heart rate. The formula most people know is 220 minus your age. It’s simple and widely used, but it was published in 1971 without any statistical analysis backing it up. A more accurate version, developed by researcher Hirofumi Tanaka, is 208 minus 0.7 times your age. In studies of adults aged 18 to 25, this formula predicted actual maximum heart rates more accurately across both sexes and different activity levels.
Here’s what that looks like in practice:
- Age 25: Max heart rate of roughly 190 bpm
- Age 35: Roughly 183 bpm
- Age 45: Roughly 176 bpm
- Age 55: Roughly 169 bpm
- Age 65: Roughly 162 bpm
These are estimates. Your true max could be 10 to 15 beats higher or lower. But they’re a solid starting point for calculating your training zones.
Target Heart Rate Zones by Intensity
The American Heart Association breaks exercise intensity into two main categories. Moderate intensity sits at 50% to 70% of your maximum heart rate. This is where brisk walking, casual cycling, and easy swimming land. You can carry on a conversation, but you’re breathing harder than at rest. For a 40-year-old with an estimated max of 180 bpm, that means keeping your heart rate between roughly 90 and 126 bpm.
Vigorous intensity covers 70% to 85% of your max. Think running, fast cycling, competitive sports, or circuit training. At this level, talking becomes difficult. For that same 40-year-old, the target range is about 126 to 153 bpm.
Going above 85% of your max is possible during short bursts like sprints or high-intensity intervals, but it’s not sustainable for long and isn’t necessary for most fitness goals. If you’re new to exercise, staying in the moderate zone gives you meaningful cardiovascular benefits without the injury risk or burnout that comes from pushing too hard too soon.
A More Personalized Calculation
The percentage-of-max approach works fine for most people, but it ignores one important variable: your resting heart rate. Someone with a resting heart rate of 55 bpm has more “room” in their cardiovascular system than someone resting at 80 bpm, even if they’re the same age.
The Karvonen method accounts for this. You subtract your resting heart rate from your max to get your heart rate reserve, then multiply by your desired intensity percentage, then add your resting heart rate back. For example, a 40-year-old with a max of 180 and a resting rate of 60 has a heart rate reserve of 120. To train at 60% intensity: 120 × 0.60 = 72, plus the resting rate of 60, equals a target of 132 bpm. That’s noticeably different from the simpler method, which would put 60% at just 108 bpm.
This method tends to be more accurate for people who are already reasonably fit, because it reflects actual cardiovascular capacity rather than just age. To use it, measure your resting heart rate first thing in the morning before getting out of bed, averaged over a few days.
Why Zone 2 Training Gets So Much Attention
If you’ve spent any time reading about fitness, you’ve probably seen “Zone 2” mentioned constantly. Zone 2 generally corresponds to about 60% to 70% of your max heart rate. It feels easy, almost too easy. You can hold a full conversation. And that’s exactly the point.
Training at this intensity stimulates your cells’ energy-producing machinery to work more efficiently. Your body gets better at burning fat as fuel, preserving its carbohydrate stores for when you actually need them. Over time, this improves your endurance, delays fatigue during longer efforts, and supports better blood sugar control and insulin sensitivity. It also builds what’s called metabolic flexibility, your body’s ability to smoothly switch between burning fat and carbohydrates depending on demand.
This is why elite endurance athletes spend the majority of their training time at low intensities. It’s not because hard workouts don’t matter. It’s because the aerobic foundation built in Zone 2 is what makes hard workouts productive. For recreational exercisers, two to four sessions per week of 30 to 60 minutes in Zone 2 delivers substantial health and fitness returns without beating up your body.
How Fitness Level Changes the Picture
Your fitness level significantly affects what a given heart rate actually means for your body. A beginner might hit 75% of their max heart rate during a light jog, while a trained runner stays at 60% of max at the same pace. As your cardiovascular system adapts to training, your heart pumps more blood per beat, so it doesn’t need to beat as fast to deliver the same amount of oxygen.
This means the standard zones are guidelines, not rules. If you’re just starting out, even the low end of a given zone might feel challenging. That’s normal, and it’s worth respecting. As one exercise physiologist at the Cleveland Clinic puts it, the lower boundary of a zone may actually be your working max for that zone when you’re starting out. Over weeks and months, you’ll notice that the same pace produces a lower heart rate. That’s a reliable sign your fitness is improving.
When Heart Rate Zones Don’t Apply
Certain medications make heart rate an unreliable measure of effort. Beta-blockers, commonly prescribed for high blood pressure and heart conditions, lower your maximum heart rate by roughly 19%. Someone on a beta-blocker might have a true exercise max of 116 bpm instead of the 145 bpm they’d reach without the medication. Using the standard formulas would set targets they could never reach, making heart rate monitoring misleading or frustrating.
If you take any medication that affects heart rate, the perceived exertion method is more useful. Rate your effort on a scale of 1 to 10: moderate exercise should feel like a 5 or 6, vigorous like a 7 or 8. You can also use the talk test. If you can speak in full sentences, you’re in moderate territory. If you can only get out a few words between breaths, you’re in vigorous territory.
How Accurate Is Your Wrist Monitor?
Most people track their heart rate with a smartwatch or fitness band, and accuracy varies more than you might expect. In a study comparing commercial devices against a medical-grade ECG, a chest strap monitor showed 98% agreement with the ECG. The Apple Watch came in at 96% agreement. Other wrist-worn devices like the Fitbit and Garmin models tested at 89% agreement, and some overestimated heart rate by an average of 6 bpm.
The bigger issue is that wrist monitors become less reliable at higher intensities. At running speeds of 8 to 9 mph, none of the wrist-worn devices in that study maintained strong agreement with the ECG. The optical sensors on your wrist struggle when your arm is moving quickly and blood flow patterns change. If you’re doing high-intensity training and want precise readings, a chest strap is the most reliable option. For moderate workouts and general tracking, a wrist device gives you a useful ballpark.
Picking the Right Zone for Your Goals
Your ideal training heart rate depends on what you’re trying to accomplish. For general health and longevity, the moderate zone (50% to 70% of max) delivers most of the cardiovascular benefits with the lowest barrier to entry. The federal physical activity guidelines recommend 150 minutes per week at this level, or 75 minutes of vigorous activity.
For fat loss and improved endurance, spending most of your time in the Zone 2 range (60% to 70%) trains your body to be a more efficient fat burner and builds the aerobic base that supports all other types of exercise. For performance, mixing in sessions at 75% to 85% of max improves your speed, power, and ability to sustain hard efforts. Most experienced coaches recommend spending about 80% of your training time at lower intensities and 20% at higher ones.
Whatever zone you train in, consistency matters more than precision. Hitting the “perfect” heart rate for one workout means far less than showing up regularly at an intensity you can sustain week after week.