For most runners, a good target is 60% to 80% of your maximum heart rate during easy and moderate runs, with harder efforts pushing into the 80% to 90% range. Your specific numbers depend on your age, resting heart rate, and fitness level. A 35-year-old with an average resting heart rate, for example, might aim for roughly 130 to 160 bpm on a typical training run.
How to Estimate Your Max Heart Rate
The classic formula is 220 minus your age. It’s simple, widely used, and decent as a starting point. But a more accurate version, developed from a meta-analysis of 351 studies involving nearly 19,000 people, puts it at 208 minus 0.7 times your age. For a 40-year-old, the classic formula gives 180 bpm, while the updated formula gives 180 as well (the two happen to converge around that age). But for a 25-year-old, the classic predicts 195 while the updated version predicts 190. For a 60-year-old, the gap flips: 160 versus 166.
Neither formula is perfect. Individual max heart rates vary by 10 to 15 bpm in either direction, even among people the same age. These formulas give you a reasonable estimate to build your training zones around, not a precise ceiling.
A More Personalized Calculation
Percentages of max heart rate treat everyone the same regardless of fitness. A better approach uses something called heart rate reserve, which accounts for your resting heart rate. The formula: subtract your resting heart rate from your max heart rate. That gap is your reserve. Then take the percentage of that reserve and add your resting heart rate back.
Here’s how it works in practice. Say you’re 30 years old with a resting heart rate of 60 bpm. Your estimated max is about 187 (using 208 minus 0.7 times 30). Your heart rate reserve is 127 beats. For a moderate run at 70% effort, you’d calculate 70% of 127 (which is 89), then add back your resting heart rate of 60, landing at 149 bpm.
This method matters because two runners with the same max heart rate but different resting rates are at very different fitness levels. The fitter runner has a larger reserve to work with, and training zones based purely on max heart rate would underestimate their easy pace and overestimate their hard pace. If you know your resting heart rate (measure it first thing in the morning before getting out of bed, for several days, and average them), the reserve method gives you more accurate zones.
Heart Rate Zones for Different Types of Runs
Most running plans organize effort into zones based on percentage of max heart rate or heart rate reserve. The specific labels vary, but the structure is consistent:
- Easy runs (60% to 70%): Comfortable, conversational pace. You should be able to speak full sentences. This is where the majority of your weekly mileage should happen.
- Moderate or tempo runs (70% to 80%): Comfortably hard. You can talk in short phrases but not hold a full conversation. This builds aerobic endurance.
- Threshold runs (80% to 90%): Hard effort, sustainable for 20 to 40 minutes. Speaking is limited to a few words at a time.
- Intervals and speed work (90% to 95%): Near-max effort in short bursts, with recovery between repeats.
One of the most common mistakes newer runners make is running easy days too fast. If your easy runs consistently land above 75% to 80% of your max, you’re likely not recovering enough between harder sessions. The “talk test” is a reliable gut check: if you can’t comfortably hold a conversation, slow down.
Why Your Watch Might Be Wrong
Wrist-based optical heart rate sensors on smartwatches are reasonably accurate during steady-state running. Average heart rate readings often land within a couple of beats per minute of a chest strap. The problem shows up during intervals, hill repeats, or any workout where your heart rate changes rapidly. Optical sensors lag behind real changes, smoothing out the spikes and dips that define interval training. A chest strap responds to heart rate shifts within about a second, while a wrist sensor can take several seconds to catch up.
There’s another quirk worth knowing. Optical sensors can sometimes confuse your running cadence with your pulse. Running cadence typically falls between 150 and 190 steps per minute, which overlaps with plausible heart rate ranges. Most watches filter for this, but none eliminate it entirely. If your heart rate data ever looks suspiciously locked to a round number or jumps erratically, cadence interference is a likely culprit. For everyday training, a wrist sensor is fine. If you’re doing structured interval work and want precise data, a chest strap is the better tool.
When Heart Rate Zones Don’t Apply
Several factors can shift your heart rate independent of effort, making the numbers on your watch misleading. Heat and humidity raise heart rate by 10 or more bpm at the same pace. Dehydration does the same. Caffeine, poor sleep, stress, and illness all push your resting and running heart rate higher than normal. On those days, your pace at a given heart rate will be slower than usual, and that’s completely fine. Trust the heart rate over the pace.
If you take beta blockers for blood pressure or another condition, standard heart rate zones won’t work for you at all. These medications slow the heart rate by design, and you may never reach your calculated target no matter how hard you push. In that case, perceived effort becomes your primary guide. A widely used approach is the Borg Rating of Perceived Exertion scale, where you rate your effort on a scale from 6 to 20. Most training runs should feel “somewhat hard,” meaning they take real work but you could keep going. If you can’t talk at all, you’re pushing too hard.
Signs You’re Consistently Overdoing It
A single hard run won’t hurt you, but chronically training at too high a heart rate without adequate recovery leads to overtraining. Early warning signs include lingering muscle soreness, disrupted sleep, unexpected weight changes, increased anxiety, and catching minor illnesses like colds more frequently. If those are ignored, more serious symptoms develop: persistent insomnia, irritability, and a resting heart rate that’s noticeably elevated above your baseline.
Paradoxically, advanced overtraining can swing in the opposite direction: an abnormally low resting heart rate, constant fatigue, depression, and a total loss of motivation to run. Tracking your resting heart rate each morning is one of the simplest ways to spot trouble early. A sustained increase of five or more beats above your normal baseline, lasting several days, is a signal to ease off. A sudden drop in performance alongside any of these symptoms is worth bringing up with a doctor.
Putting It All Together
Start by estimating your max heart rate with 208 minus 0.7 times your age. Measure your resting heart rate over a few mornings. Use the heart rate reserve method to calculate your personal zones. Run most of your miles in the easy zone, and pay attention to how your body feels rather than obsessing over every beat. If you’re newer to running, expect your heart rate to be higher at slower paces. That’s normal and will improve as your cardiovascular fitness develops over weeks and months. The goal isn’t to hit a specific number on every run. It’s to train at the right intensity for the purpose of that day’s workout.