Heart Rate Training Zones: The Complete Guide for Runners
How to calculate your training zones, what each zone trains, and how to use heart rate data to run smarter — not just harder.
Pace can lie — a 9:00/mile on a hot day is harder than 8:30 on a cool morning. Heart rate reveals the true effort. When you pair HR with pace, you train smarter and avoid the common mistake of running too hard on easy days.
Use heart rate to:
- Keep easy days easy: Drift into Zone 3 and you're not recovering
- Hit the right effort on hard days: HR confirms you're in the threshold zone, not just guessing
- Track fitness over time: Same pace at lower HR = you're getting fitter
- Spot fatigue early: Rising resting HR is a warning sign before you feel overtrained
The Five Training Zones
Most heart rate training systems use five zones, each targeting different physiological adaptations:
| Zone | % Max HR | Feel | Training Benefit |
|---|---|---|---|
| Zone 1 | 50-60% | Very easy, conversational | Active recovery |
| Zone 2 | 60-70% | Easy, can hold conversation | Aerobic base, fat burning |
| Zone 3 | 70-80% | Moderate, short sentences | Aerobic capacity |
| Zone 4 | 80-90% | Hard, few words at a time | Lactate threshold |
| Zone 5 | 90-100% | Max effort, can't talk | VO2max, speed |
Example: Zones for Max HR 188
How to Find Your Max Heart Rate
Your max heart rate (Max HR) is the foundation for calculating zones. There are several ways to estimate it:
Method 1: Age-Based Formula (Simplest)
The classic formula is 220 - age. Simple, but it's a population average with significant individual variation (±10-12 bpm). A 40-year-old could have a true max HR anywhere from 168 to 192. Many runners underestimate their max HR, which skews all their zones too low.
Method 2: Field Test (Most Accurate)
The best way to find your true max HR is to test it:
- Warm up thoroughly (15-20 minutes easy running)
- Find a hill or track
- Run 3-4 intervals of 2-3 minutes at increasing intensity
- Final interval: all-out effort for 2 minutes
- Sprint the last 30 seconds as hard as possible
- The highest number you see is approximately your max HR
Safety Note:
Max HR tests are extremely demanding. Only do them if you're healthy and have a solid fitness base. Consider consulting a doctor first, especially if you're over 40 or have any cardiac concerns.
Method 3: Race Data
Check your highest HR from a recent all-out 5K or shorter race. This is usually within 5 beats of your true max.
Two Ways to Calculate Zones
Percentage of Max HR (Simple)
Multiply your max HR by the zone percentages. If your max is 190:
- Zone 2 (60-70%): 114-133 bpm
- Zone 4 (80-90%): 152-171 bpm
Heart Rate Reserve / Karvonen Method (More Accurate)
This method accounts for your resting heart rate, giving more personalized zones. The formula:
Target HR = ((Max HR - Resting HR) × % intensity) + Resting HR
If your max is 190, resting is 50, and you want Zone 2 (60-70%):
- HRR = 190 - 50 = 140
- Zone 2 low: (140 × 0.60) + 50 = 134 bpm
- Zone 2 high: (140 × 0.70) + 50 = 148 bpm
Notice how Karvonen gives higher numbers for the same zone? That's because it accounts for fitness — a lower resting HR shifts the zones up appropriately.
Matching HR Zones to Training Paces
Heart rate zones align with Jack Daniels' training pace system. Here's how they map:
| Training Pace | % Max HR | % HRR (Karvonen) |
|---|---|---|
| Easy | 65-79% | 59-74% |
| Marathon | 80-90% | 75-84% |
| Threshold | 88-92% | 83-88% |
| CV (Critical Velocity)* | 92-96% | 88-92% |
*CV efforts are short enough that HR may not fully stabilize
For VO2max and Repetition paces, heart rate isn't as useful — the intervals are too short for HR to stabilize and accurately reflect effort.
Run Studio tip: Enter your HR data once and you'll see targets alongside your VDOT training paces automatically.
Common Heart Rate Training Mistakes
1. Easy runs aren't easy enough
Most runners go too hard on easy days. If you're constantly in Zone 3 on "easy" runs, you're accumulating fatigue without the recovery benefit. Slow down until you're solidly in Zone 2.
2. Using the wrong max HR
If your zones feel way off, your estimated max HR is probably wrong. Do a field test or use race data to get a more accurate number.
3. Ignoring cardiac drift
Heart rate naturally rises during long runs even at constant effort (cardiac drift). Don't chase the same HR for 2 hours — accept that late-run HR will be higher for the same pace.
4. HR obsession during intervals
For short, hard efforts (400s, 800s), pace matters more than HR. Heart rate lags behind effort, so it won't give you useful real-time feedback during these workouts.
When to Ignore Heart Rate
Heart rate is useful most of the time, but not always. Ignore it when conditions distort the signal:
- Heat and humidity: HR rises 10+ bpm for the same effort in hot weather
- Hills: HR spikes on climbs and drops on descents — use effort, not HR
- Altitude: Reduced oxygen = elevated HR at the same pace
- Caffeine or poor sleep: Both raise resting and working HR
- Short intervals: HR lags 30-60 seconds behind effort — pace matters more for reps under 2 minutes
On these days, trust perceived effort over the number on your watch.
Practical Tips for HR Training
- Trust the process: Running slow feels wrong at first. Do it anyway — easy runs build your aerobic engine
- Use HR for easy days, pace for hard days: The combination gives you the best of both worlds
- Check resting HR regularly: A consistent reading 5+ bpm above normal can indicate overtraining or illness
- Account for conditions: Heat, humidity, caffeine, and stress all elevate HR independent of effort
- Be patient with the data: HR training takes 4-6 weeks before you see clear patterns emerge
Calculate Your Heart Rate Zones
Enter your heart rate data in the Heart Rate Zones tab, then calculate your VDOT — you'll see HR targets for each training pace automatically.
Open Heart Rate Zone Calculator