Your heart rate while running should generally fall between 50% and 85% of your maximum heart rate, depending on your goal for that run. For most people, that translates to somewhere between 100 and 170 beats per minute, though your specific numbers depend on your age, fitness level, and what kind of run you’re doing. An easy jog and an all-out sprint place very different demands on your heart, and understanding where your rate should land for each type of effort helps you train smarter and avoid pushing too hard.
How to Find Your Maximum Heart Rate
Every heart rate target starts with knowing your maximum, the fastest your heart can beat during all-out effort. The simplest way to estimate it is to subtract your age from 220. A 35-year-old, for example, would get a max of 185 beats per minute. A 50-year-old would land at 170.
This formula (known as the Fox equation) has been around for decades and remains the most widely used. A slightly newer version, 208 minus 0.7 times your age, was developed to improve accuracy. In practice, a 2020 study in the International Journal of Exercise Science found both formulas performed similarly, with roughly the same margin of error of about 11 beats per minute in either direction. That’s a significant spread, which means these formulas give you a starting point, not a precise number. If your calculated zones feel way off from your actual effort, trust your body. The only way to know your true max is through a supervised maximal exercise test.
Here are estimated maximum heart rates by age using the 220-minus-age formula:
- Age 25: 195 bpm
- Age 30: 190 bpm
- Age 35: 185 bpm
- Age 40: 180 bpm
- Age 45: 175 bpm
- Age 50: 170 bpm
- Age 55: 165 bpm
- Age 60: 160 bpm
Heart Rate Zones for Running
Once you have your estimated max, you can break your effort into five zones. Each zone corresponds to a percentage range of that max and serves a different training purpose.
- Zone 1 (50% to 60%): Very light effort. Think warm-ups, cool-downs, and recovery jogs. You can hold a full conversation without any strain. For a 35-year-old with a max of 185, this is roughly 93 to 111 bpm.
- Zone 2 (60% to 70%): Easy, sustainable running. This is where most of your weekly mileage should happen. You can talk in complete sentences but notice you’re working. For that same 35-year-old, about 111 to 130 bpm.
- Zone 3 (70% to 80%): Moderate effort, often called “tempo” territory. Conversation becomes choppy. You’re working harder, but it’s sustainable for 20 to 40 minutes. Roughly 130 to 148 bpm.
- Zone 4 (80% to 90%): Hard running. You can manage only a few words at a time. This is interval and threshold training, typically done in bursts of a few minutes. About 148 to 167 bpm.
- Zone 5 (90% to 100%): All-out, race-finish effort. Unsustainable for more than a minute or two. Reserved for short sprints and max-effort intervals. Roughly 167 to 185 bpm.
Where Most Runners Should Spend Their Time
The biggest mistake recreational runners make is running too hard on easy days. Most training plans call for 70% to 80% of your runs at a conversational, Zone 2 pace. This builds your aerobic engine: your heart gets more efficient at pumping blood, your muscles develop more blood vessels, and your body gets better at burning fat for fuel. It feels slow, and that’s the point.
The remaining runs (roughly 20% to 30% of your weekly volume) should include harder efforts in Zones 3 through 5. These sessions improve your speed, raise the intensity you can sustain before fatigue sets in, and train your body to clear lactic acid more efficiently. Without that Zone 2 base, though, hard sessions become harder to recover from and easier to overtrain on.
If you’re new to running, Johns Hopkins Medicine recommends starting at around 50% of your max heart rate and gradually building intensity over weeks. There’s no rush to push into higher zones. Fitness gains at lower intensities are real and sustainable, and they reduce your risk of injury while your muscles, tendons, and cardiovascular system adapt.
Your Anaerobic Threshold and Why It Matters
As you increase your pace, there’s a tipping point where your body can no longer fuel the effort with oxygen alone. Below this threshold, your muscles burn fuel aerobically, and you can keep going for a long time. Above it, your muscles start relying more heavily on anaerobic energy, producing lactic acid faster than your body can clear it. Fatigue builds quickly.
For most runners, this threshold falls somewhere around 80% to 90% of max heart rate, roughly in the Zone 4 range. Trained endurance athletes tend to have a higher threshold, meaning they can run at a faster pace before crossing that line. One of the main goals of consistent training is to push this threshold upward so you can sustain a harder effort for longer.
You don’t need a lab test to get a rough sense of where yours is. If you can run at a given pace for about 30 to 60 minutes before your legs feel heavy and your breathing becomes labored, you’re likely near your threshold. A pace you can only hold for 10 to 15 minutes before hitting a wall is probably above it.
Using Resting Heart Rate for More Accuracy
A more personalized approach factors in your resting heart rate, which reflects your baseline fitness. This method, called the Karvonen formula, works like this: subtract your resting heart rate from your max, multiply by your target percentage, then add your resting heart rate back.
For example, a 40-year-old with a resting rate of 60 bpm would have a max of 180. Their “heart rate reserve” is 120 (180 minus 60). To find a Zone 2 target at 65%, they’d calculate 120 times 0.65, getting 78, then add back 60 for a target of 138 bpm. Someone the same age with a resting rate of 75 (heart rate reserve of 105) would get a Zone 2 target of about 143 bpm using the same percentage. The difference is small but meaningful over time, especially if your resting heart rate is notably high or low compared to average.
To find your resting heart rate, check your pulse first thing in the morning before getting out of bed, ideally averaged over several days. Most adults land between 60 and 100 bpm, with fitter individuals often falling in the 50s or even 40s.
Why Your Heart Rate Drifts During a Run
If you’ve noticed your heart rate climbing during a long run even though your pace stays the same, you’re experiencing cardiac drift. This is normal. As you exercise, your body temperature rises, blood vessels near the skin dilate to release heat, and your blood volume effectively decreases through sweat. Your heart compensates by beating faster to maintain the same output.
Heat and humidity accelerate this effect significantly. Research from the National Institutes of Health found that cardiovascular drift begins roughly 20 minutes before the body reaches the point of uncompensable heat stress, meaning your heart rate starts climbing well before you feel overheated. On a hot, humid day, a pace that normally puts you in Zone 2 might push you into Zone 3 or higher. This is one reason experienced runners adjust their pace downward in warm weather rather than chasing a specific speed. Targeting heart rate instead of pace on these days keeps the actual training stress where you want it.
Dehydration, sleep quality, caffeine, and stress can all shift your heart rate upward on any given day, sometimes by 5 to 15 beats per minute. If your numbers seem unusually high for the effort, those factors are often the explanation.
Signs Your Heart Rate Is Too High
Pushing hard during a run is normal. But certain symptoms signal that your body is under more stress than it can handle safely. Chest pain, dizziness, lightheadedness, feeling faint, or unusual shortness of breath that doesn’t match the effort are all reasons to stop running immediately. Palpitations, a sensation of your heart racing, pounding, or flopping in your chest, also warrant stopping.
Less dramatic but still important: if you consistently find yourself unable to complete runs, feel wiped out for hours afterward, or notice your resting heart rate trending upward over days, you’re likely training at an intensity your body hasn’t adapted to yet. Pulling back to lower zones for a few weeks lets your cardiovascular system catch up.