What Is Zone 2 Heart Rate? (Zone 2 Training Explained)
Your zone 2 heart rate is 60 to 70 percent of your maximum heart rate, the easy aerobic effort where you can still hold a conversation. For a 40-year-old that is about 108 to 126 bpm using the standard 220 minus age estimate. Zone 2 is the aerobic training intensity where your body primarily burns fat for fuel while building mitochondrial density. It's the foundation of endurance fitness and is characterized by:
Zone 2 Indicators
- Can breathe through nose only
- Can hold a full conversation
- Feels "easy" to sustainable
- 60-70% of max heart rate
- RPE 3-4 out of 10
Zone 2 Benefits
- Maximizes fat oxidation
- Builds mitochondrial density
- Improves aerobic base
- Low injury risk
- Fast recovery between sessions
Zone 2 Heart Rate by Age (Complete Chart)
At age 30, a max heart rate of 190 puts Zone 2 between 114 and 133, and this chart lists Zone 2 and MAF targets by age.
| Age | Max HR | Zone 2 Low (60%) | Zone 2 High (70%) | MAF (180-age) |
|---|---|---|---|---|
| 20 | 200 | 120 | 140 | 160 |
| 25 | 195 | 117 | 137 | 155 |
| 30 | 190 | 114 | 133 | 150 |
| 35 | 185 | 111 | 130 | 145 |
| 40 | 180 | 108 | 126 | 140 |
| 45 | 175 | 105 | 123 | 135 |
| 50 | 170 | 102 | 119 | 130 |
| 55 | 165 | 99 | 116 | 125 |
| 60 | 160 | 96 | 112 | 120 |
| 65 | 155 | 93 | 109 | 115 |
| 70 | 150 | 90 | 105 | 110 |
* Max HR calculated using 220-age formula. For more accuracy, use the Karvonen method with your actual resting heart rate.
Zone 2 Calculation Methods
1. MAF Formula (Dr. Phil Maffetone)
Adjustments:
- Subtract 10: Recovering from major illness or injury
- Subtract 5: Inconsistent training or frequent colds
- No change: Training consistently for up to 2 years
- Add 5: Training consistently 2+ years without injuries
Example: 40-year-old consistent runner: 180 - 40 = 140 bpm ceiling
2. Percentage of Max HR (Standard)
Example: 40-year-old: Max HR = 180, Zone 2 = 108-126 bpm
Note: The 220-age formula can be inaccurate by ±10-12 bpm. If you know your actual max HR from testing, use that instead.
3. Karvonen Formula (Heart Rate Reserve)
Example: Max HR 180, Resting HR 60:
Low: ((180-60) × 0.60) + 60 = 132 bpm
High: ((180-60) × 0.70) + 60 = 144 bpm
The Karvonen method is more accurate because it accounts for individual fitness levels through resting heart rate.
Zone 2 by Age and Resting Heart Rate (Karvonen)
| Age | RHR 50 | RHR 60 | RHR 70 | |||
|---|---|---|---|---|---|---|
| 60% | 70% | 60% | 70% | 60% | 70% | |
| 30 | 134 | 148 | 138 | 151 | 142 | 154 |
| 35 | 131 | 145 | 135 | 148 | 139 | 151 |
| 40 | 128 | 141 | 132 | 144 | 136 | 147 |
| 45 | 125 | 138 | 129 | 141 | 133 | 144 |
| 50 | 122 | 134 | 126 | 137 | 130 | 140 |
| 55 | 119 | 131 | 123 | 134 | 127 | 137 |
| 60 | 116 | 127 | 120 | 130 | 124 | 133 |
RHR = Resting Heart Rate. Measure your resting HR first thing in the morning before getting out of bed.
Get Your Personalized Zone 2
Use our Zone 2 Calculator for precise heart rate zones using MAF, Karvonen, and 3 other proven formulas.
Open Zone 2 CalculatorHow to Train in Zone 2
Duration
45-90 minutes per session. The aerobic adaptations require sustained effort. Start with 30-45 minutes if new to Zone 2.
Frequency
3-4 sessions per week. Elite endurance athletes do 4-6 hours of Zone 2 weekly. Start with 2-3 hours total.
Activities
Running, cycling, swimming, rowing, hiking. Any sustained cardio works. Mix activities to reduce injury risk.
Pacing
Slow down on hills to stay in zone. Walk if needed. Zone 2 often feels "too easy" - that's correct!
The Talk Test
If you can't hold a conversation or need to breathe through your mouth, you're above Zone 2. Slow down until you can speak in full sentences comfortably.
Common Zone 2 Training Mistakes
Going Too Fast
The #1 mistake. Zone 2 should feel easy. If your ego says slow down, listen to it. Many people's "easy" pace is actually Zone 3-4.
Too Short
Zone 2 benefits require time. A 20-minute Zone 2 run provides minimal aerobic benefit. Aim for 45+ minutes.
Inconsistency
Zone 2 benefits compound over weeks and months. One session per week won't build your aerobic base. Aim for 3-4 weekly.
Using Wrong HR Zones
Generic watch zones are often wrong. Calculate your personal zones using the formulas above, or use the Karvonen method for best accuracy.
Gear for Accurate Zone 2 Training
The #1 Zone 2 mistake is training off inaccurate heart rate data. A chest strap reads continuously and won't lag like a wrist sensor: essential for staying inside a narrow Zone 2 band.
Polar H10
The gold-standard chest strap. Pairs with Garmin, Apple Watch, Wahoo, and any Bluetooth/ANT+ device. under $250.
Check Backcountry → Check Price on AmazonGarmin Forerunner 265
Live HR-zone alerts buzz you the moment you drift out of Zone 2, plus VO2 max and training-load tracking. under $500.
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More questions answered
How do I calculate my Zone 2 heart rate?
The simplest method is the MAF formula: 180 minus your age. For example, a 40-year-old would have a Zone 2 ceiling of 140 bpm. More accurate methods use 60-70% of max heart rate (220 minus age) or the Karvonen formula which factors in resting heart rate.
How do I know if I'm in Zone 2?
You're in Zone 2 if you can: breathe through your nose only, hold a full conversation without gasping, feel like you could maintain the pace for hours, and your heart rate stays between 60-70% of max. The 'talk test' is the simplest way to verify Zone 2.
How long should Zone 2 workouts be?
Zone 2 workouts should be 45-90 minutes for optimal benefits. The aerobic adaptations that Zone 2 targets (mitochondrial density, fat oxidation) require sustained effort. Aim for 3-4 Zone 2 sessions per week, totaling 4-6 hours weekly for serious endurance athletes.
What is the MAF heart rate formula?
The MAF (Maximum Aerobic Function) formula by Dr. Phil Maffetone is: 180 minus your age, then adjust: subtract 10 if recovering from illness/injury, subtract 5 if inconsistently training, add 5 if training consistently for 2+ years with no injuries.
