Heart Rate Zone Methods Compared: MaxHR% vs HRR vs LTHR
Three methods to calculate heart rate training zones — each with different strengths. Learn which one matches your training approach and available data.
- MaxHR% is the simplest method but least personalized — it ignores your resting heart rate and fitness level.
- Heart Rate Reserve (Karvonen) accounts for resting HR, giving more individualized zones that better reflect your actual fitness.
- LTHR-based zones are the most physiologically accurate, anchoring zones to your actual lactate threshold.
- The "best" method depends on what data you have — MaxHR only, MaxHR + RHR, or actual LTHR from a test.
- Whichever method you choose, consistency in using it matters more than which method is theoretically superior.
Table of Contents
What Are Heart Rate Training Zones?
Heart rate training zones divide your effort range into distinct intensity levels, each targeting different physiological adaptations. Training in specific zones helps you control workout intensity with precision rather than relying on perceived effort alone.
Most systems use five zones, though the exact boundaries and names vary by method. The key insight is that different intensities produce different training effects — and getting these boundaries right determines whether your easy runs are truly easy and your hard runs are hard enough.
| Zone | Name | Effort |
|---|---|---|
| Zone 1 | Recovery | Very easy, conversational |
| Zone 2 | Aerobic / Endurance | Easy, can hold a full conversation |
| Zone 3 | Tempo | Moderate, can speak in short sentences |
| Zone 4 | Threshold | Hard, can only say a few words |
| Zone 5 | VO2 Max | Very hard, cannot speak |
Method 1: MaxHR Percentage
The simplest approach: take a percentage of your maximum heart rate to define each zone. This is what most consumer watches and apps use as the default.
Formula:Zone boundary = MaxHR × percentageThe typical zone ranges are Zone 1: 50-60%, Zone 2: 60-70%, Zone 3: 70-80%, Zone 4: 80-90%, Zone 5: 90-100%. However, these generic percentages often place Zone 2 too low for trained runners, meaning your "easy" zone may actually be below the intensity needed for optimal aerobic development.
Example
For a runner with MaxHR of 185 bpm: Zone 2 = 111-130 bpm (60-70% of 185). Zone 4 = 148-167 bpm (80-90% of 185).
Advantages
- Requires only one data point (MaxHR)
- Simple to calculate and understand
- Widely supported by watches and apps
Limitations
- Ignores resting heart rate and fitness level
- Zone 2 is often set too low for trained runners
- 220-age formula for MaxHR has a standard deviation of ±10-12 bpm
Method 2: Heart Rate Reserve (Karvonen)
The Karvonen method uses Heart Rate Reserve (HRR) — the difference between your max and resting heart rate — to calculate zones. By factoring in resting HR, it accounts for individual fitness level, since fitter runners tend to have lower resting heart rates.
Formula:Target HR = (MaxHR - RHR) × percentage + RHRThis shifts all zones upward compared to straight MaxHR%, which better reflects the usable range of heart rates. The Karvonen Zone 2 more closely aligns with the actual aerobic zone where meaningful endurance adaptations occur.
Example
For a runner with MaxHR 185, RHR 50: HRR = 135. Zone 2 = 50 + (135 × 0.60) to 50 + (135 × 0.70) = 131-145 bpm. Notice how this is higher than the MaxHR% method (111-130).
Advantages
- Accounts for individual fitness via resting HR
- Zone 2 aligns better with actual aerobic intensity
- More personalized than MaxHR% alone
Limitations
- Requires accurate MaxHR AND resting HR
- RHR varies with fatigue, hydration, and stress
- Still uses generic percentages, not physiological thresholds
Method 3: Lactate Threshold Heart Rate (LTHR)
LTHR-based zones are anchored to your actual lactate threshold — the intensity where lactate starts accumulating faster than your body can clear it. This is the most physiologically meaningful reference point because it directly reflects your current metabolic fitness.
Rather than using generic percentages of MaxHR, LTHR zones define each zone relative to your threshold heart rate. Zone 2 sits well below threshold, Zone 4 brackets it, and Zone 5 is above it.
Zone definitions (Joe Friel model):Z1: <85% LTHR | Z2: 85-89% | Z3: 90-94% | Z4: 95-99% | Z5: 100%+The key advantage is that these zones shift automatically as your fitness changes. As your LTHR improves, all zones move up accordingly — your easy pace becomes what used to be moderate, and threshold pace increases.
Example
For a runner with LTHR 168: Zone 2 = 143-150 bpm (85-89%). Zone 4 = 160-166 bpm (95-99%). These zones are anchored to actual physiology rather than estimated maximums.
Advantages
- Zones are anchored to actual metabolic threshold
- Most accurate reflection of current fitness
- Zones automatically adjust as LTHR changes
Limitations
- Requires lab test or field test to determine LTHR
- LTHR can shift over a training cycle
- Less convenient to set up initially
Side-by-Side Comparison
Here is how the three methods compare across key dimensions. The right choice depends on your available data and training goals.
| Feature | MaxHR% | HRR (Karvonen) | LTHR |
|---|---|---|---|
| Data required | MaxHR only | MaxHR + RHR | LTHR (test) |
| Setup difficulty | Very easy | Easy | Moderate |
| Personalization | Low | Medium | High |
| Zone 2 accuracy | Often too low | Good | Best |
| Fitness-adaptive | No | Partially (via RHR) | Yes |
| Best for | Beginners | Intermediate | Serious runners |
| Watch support | Universal | Most watches | Garmin, Polar, etc. |
Which Method Should You Use?
The best method is the one that matches your current data and commitment level. Here is a practical guide:
Just starting out? Use MaxHR%
If you only know your approximate max heart rate (from a recent hard effort or using 220-age as a rough estimate), MaxHR% zones will get you started. They are better than no zones at all. Focus on keeping easy runs in Zone 2 and you will be ahead of most runners.
Know your resting HR? Use Karvonen (HRR)
If you track your resting heart rate (most GPS watches do this automatically), the Karvonen method gives meaningfully better zones. The Zone 2 range will be more accurate, which is critical since most of your training should be there.
Serious about training? Use LTHR
If you have had a lactate threshold test (lab or field test), LTHR zones are the gold standard. They reflect your actual physiology and adjust as your fitness changes. Re-test every 8-12 weeks during a training block.
Common Mistakes to Avoid
Even with properly calculated zones, runners frequently make these errors:
Using 220-age as gospel
The 220-age formula has a standard deviation of ±10-12 bpm. A 35-year-old could have a true MaxHR anywhere from 173 to 197. Use an actual max effort test if possible.
Running Zone 2 too fast
Zone 2 should feel genuinely easy — you should be able to hold a full conversation. If you are breathing through your mouth, you are probably in Zone 3.
Not re-testing periodically
Your MaxHR, RHR, and LTHR all change with fitness. Re-evaluate your zones every 2-3 months, especially if training is going well.
Ignoring cardiac drift
Heart rate rises during a run even at constant effort (cardiac drift). A 60-minute easy run might start in Zone 2 and drift into Zone 3 — this is normal and does not mean you need to slow down.
Mixing methods
Pick one method and be consistent. Mixing MaxHR% for some zones and Karvonen for others creates incoherent training targets.
Frequently Asked Questions
Can I use the same heart rate zones for cycling and running?
No. Heart rate zones differ between sports because different muscle groups are engaged. Running typically produces higher heart rates than cycling at the same perceived effort. Set separate zones for each sport.
How often should I recalculate my heart rate zones?
Every 2-3 months, or whenever you notice a significant shift in fitness. If your resting HR drops noticeably, or if your easy pace at the same HR gets faster, it is time to re-test.
Why does my watch show different zones than what I calculated?
Most watches default to MaxHR% with generic thresholds. Update your watch settings with your actual MaxHR, RHR, and/or LTHR to get personalized zones.
Is Zone 3 really a 'junk zone' to avoid?
Zone 3 is not junk — it has a purpose in tempo and marathon-pace training. The problem is spending too much time there when you intended to be in Zone 2. Polarized training (mostly Zone 1-2, some Zone 4-5) is effective, but Zone 3 has its place in a well-structured plan.
Does heat or altitude affect my heart rate zones?
Yes. Heat and altitude both elevate heart rate at any given effort. In hot conditions or at altitude, your heart rate will be 5-15 bpm higher than normal. Some coaches recommend adjusting zones upward by 5-10% in extreme conditions, or using perceived effort as a secondary guide.
Calculate Your Heart Rate Zones
Use our free HR Zone Calculator to calculate your personalized training zones using any of the three methods discussed in this article.
Try HR Zone Calculator