What is Zone 2 heart rate as a percentage of max heart rate?

Zone 2 heart rate is 60–70% of your maximum heart rate. For most adults, this produces a moderate, sustainable effort where conversation is easy but breathing is noticeably elevated.

How do I find my Zone 2 without a heart rate monitor?

Use the talk test. If you can speak in full sentences but cannot sing comfortably, you are likely in Zone 2. An RPE of around 4 out of 10 is the corresponding perceived effort.

Is the Karvonen formula better than the 220 minus age method?

Yes. The Karvonen formula accounts for your resting heart rate, which reflects your fitness level, producing a more personalized and accurate Zone 2 range than age-based estimates alone.

Does Zone 2 training actually burn fat?

Zone 2 burns a higher percentage of fat as fuel compared to higher intensities, but total calorie burn over time determines body composition outcomes more than training zone alone.

What Is My Heart Rate Zone 2? Calculate Yours Now

Q: How long should a Zone 2 session last?

Sessions of 45–90 minutes produce the strongest aerobic adaptations. Shorter sessions still provide benefit, but longer aerobic exposure generates a stronger mitochondrial response.

Zone 2 heart rate is moderate aerobic exercise at 60–70% of your maximum heart rate. For a 40-year-old man that is roughly 108–126 bpm; for a 30-year-old man, 112–131 bpm. This guide compares the three main calculation methods and shows how to structure Zone 2 into your week.

How to Calculate Your Zone 2 Heart Rate

Tanaka (208 − 0.7 × age) — our default for men: A 40-year-old: HRmax ≈ 180 bpm, Zone 2 ≈ 108–126 bpm. A 50-year-old: HRmax ≈ 173 bpm.
Fox (220 − age) — historical reference: Fast and popular, but ±10–12 bpm variability and it overestimates for active adults.
Karvonen (uses resting HR): Zone 2 = (HRmax − HRrest) × 0.60–0.70 + HRrest. A 40-year-old with HRmax 180 and HRrest 55 gets 130–143 bpm — a personalized range that shifts with fitness.

Why Zone 2 Works: The Physiology

Zone 2 sits just below the lactate threshold. Consistent training in this range increases mitochondrial density in slow-twitch muscle fibers, improves fat oxidation, and produces eccentric cardiac hypertrophy — the heart chambers enlarge and stroke volume rises. Trained endurance athletes often see resting heart rates in the low 40s as a result.

How to Verify You Are in Zone 2

Talk test: full sentences yes, singing no.
RPE ≈ 4/10: steady, sustainable, not comfortable.
Watch for HR drift on longer sessions — heat and fatigue push HR up at the same pace.
Use walk breaks when HR climbs above the ceiling. Not a failure — a legitimate reset tool.

Structuring Zone 2 Into Your Week

Follow the polarized 80/20 model: ~80% of weekly training in Zone 2, ~20% in Zones 4–5. Aim for 3–5 sessions per week of 45–90 minutes each. Track pace or power at the same heart rate over weeks — when you go faster at the same Zone 2 HR, your aerobic base is growing.

Zone 2 FAQ

What is Zone 2 heart rate as a percentage of max?

60–70% of your maximum heart rate.

How do I find Zone 2 without a monitor?

Use the talk test and target RPE 4/10.

Is Karvonen better than 220 − age?

Yes — it personalizes the range using resting heart rate.

How long should a Zone 2 session last?

45–90 minutes maximizes mitochondrial adaptation.

Does Zone 2 burn fat?

Higher fat percentage per minute than harder work, but total energy balance drives body composition.

Disclaimer: This calculator is for informational purposes only and does not provide medical advice. Always consult with a healthcare professional before starting any new exercise program.

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