Zone 2 Cardio for Fat Loss: Heart Rate and Treadmill Settings

Zone 2 cardio is steady, easy-to-moderate exercise where you can still talk in full sentences, usually estimated at 60–70% of your maximum heart rate. For a 30-year-old that's roughly 112–131 beats per minute. It helps with fat loss mainly because it's easy to recover from, so you can do a lot of it, but it doesn't burn fat by magic. Your total calories over weeks still decide whether you lose fat.

Find your own range with the heart rate zone calculator, then use the steps below to turn it into treadmill settings that fit your body, not someone else's.

What exactly is zone 2?

Most fitness watches split effort into five heart rate zones. Zone 2 is the second-easiest. There's no single scientific definition, which is part of the confusion. A 2025 expert panel of 14 sport scientists and coaches agreed zone 2 is best described as the intensity just below your first lactate or ventilatory threshold, the point where breathing starts to pick up noticeably.

You can't measure that threshold without a lab test, so in practice people use two stand-ins:

• Percentage of max heart rate, commonly 60–70% for zone 2.
• The talk test. The CDC's rule of thumb is that during moderate-intensity activity you can talk but not sing; during vigorous activity you can't say more than a few words without pausing for breath. Zone 2 sits at the easier end of "can talk": full sentences, a bit of effort, no gasping.

For context, the American College of Sports Medicine describes moderate intensity as about 65–75% of max heart rate, or an effort of 3–4 out of 10. Zone 2 overlaps the lower part of that.

What is my zone 2 heart rate by age?

Max heart rate is usually estimated from age. The old 220 − age formula is simple, but a large analysis by Tanaka and colleagues found 208 − 0.7 × age fits better, especially for older adults. Here's zone 2 (60–70%) with both:

These are population averages. Your real max can be well above or below the formula, which is why the talk test matters. If 125 bpm feels like you're gasping, you're not in zone 2, whatever the chart says. If you're on beta blockers or any heart medicine, heart rate targets don't apply; ask your doctor what to use instead.

Is the "fat burning zone" real?

Half real. At low intensities, a larger share of the energy you burn comes from fat. In a study of 300 men and women by Venables, Achten and Jeukendrup, the rate of fat burning peaked at about 48% of VO₂max on average, which was about 62% of max heart rate. That's right in zone 2.

But here's the nuance most posts skip:

• Fat lost from your body depends on your energy balance over days and weeks, not on which fuel you used during one session. Burning a higher percentage of fat for 40 minutes doesn't help if the total burned is small or you eat it straight back.
• Harder sessions burn more total calories per minute. A meta-analysis comparing interval training with steady moderate cardio in overweight adults found similar reductions in body fat and waist size, with intervals taking about 40% less time.
• Zone 2 isn't the best option for everything. A 2025 review in Sports Medicine argued the evidence doesn't support zone 2 as the best intensity for fitness or mitochondrial health in the general public, and that some higher-intensity work matters, especially if you don't train many hours.

So why bother with zone 2? Because it's sustainable. You can walk on an incline for 45 minutes four days a week and still lift weights well. You can't do hard intervals that often without wrecking your legs and your mood. For most beginners, the plan that gets done beats the "optimal" one that doesn't.

How do you find your zone 2 treadmill settings?

There's no universal "zone 2 is 6 km/h at 8% incline". It depends on your fitness, weight and leg length. Find yours in about 15 minutes:

1. Wear a heart rate monitor. A chest strap is more reliable than a wrist watch; the treadmill's hand grips are the least reliable.
2. Warm up for 5 minutes at an easy walk, 0–1% incline.
3. Every 2 minutes, raise the incline by 1–2% (or the speed by 0.3–0.5 km/h if you prefer flat).
4. Watch your heart rate and try talking (or count out loud). When you reach the bottom of your zone 2 and can still speak in full sentences, note the speed and incline.
5. Hold it for 10 minutes. Heart rate drifts up over time. If it climbs past the top of your zone, lower the incline a notch.
6. Write the setting down and retest every 4–6 weeks. As you get fitter, you'll need more speed or incline for the same heart rate.

Many beginners land on a brisk walk with some incline. Fitter people often need a slow jog to get into zone 2. Both are fine.

How many calories does it burn?

The 2024 Adult Compendium of Physical Activities gives energy costs in METs, where 1 MET is 1 kcal per kg of body weight per hour. Some walking entries:

The formula is METs × weight in kg × hours. These figures include the energy you'd burn sitting anyway (1 MET), so the extra burn is a bit lower. Lighter people burn less; heavier people more.

How many calories do 10,000 steps burn?

ACSM uses about 100 steps per minute as a marker of moderate-intensity walking. At that cadence, 10,000 steps takes around 100 minutes. For a 70 kg person at 3.8 METs:

3.8 × 70 × (100 ÷ 60) ≈ 440 kcal in total, or about 330 kcal above sitting.

Most of your daily steps are slower than that (walking around the house, to the shop), so treat this as an upper estimate. And 10,000 isn't a magic number. A meta-analysis of 15 cohorts found the risk of death kept falling with more steps up to about 6,000–8,000 a day in adults over 60 and about 8,000–10,000 in younger adults. More steps are still useful for burning calories; it's just not a cliff at 9,999.

A simple weekly plan

WHO guidelines recommend 150–300 minutes of moderate aerobic activity a week for adults, plus muscle-strengthening on 2 or more days. A practical way to fit zone 2 into that:

That's roughly 170–200 minutes of cardio plus three strength days. If you're new to lifting, follow the beginner gym workout plan for the strength days.

Cardio alone won't fix the diet

Here's the honest arithmetic. A 45-minute zone 2 incline walk might burn 300–370 kcal at 70 kg. A plate of chole bhature is around 650–800 kcal (see street food calories). You can't outwalk your plate every day, and you don't need to.

What works is cardio plus a modest calorie deficit. Work out your maintenance and target with the calorie calculator, and read calorie deficit and maintenance calories for how to set it without crash dieting.

Quick checklist

• Zone 2 ≈ 60–70% of max HR; at 30 that's about 112–131 bpm
• Use 208 − 0.7 × age for max HR, then confirm with the talk test
• Find your own speed and incline with a heart rate monitor; retest every 4–6 weeks
• Fat burning peaks at easy intensities, but total calories decide fat loss
• Aim for 150–300 minutes a week plus 2–3 strength sessions
• Add one harder session only once easy cardio feels comfortable

This is general information, not medical advice. If you have heart disease, high blood pressure, diabetes, take heart medicines, are pregnant, are under 18, or get chest pain, dizziness or unusual breathlessness when exercising, see a doctor before starting or changing a cardio plan.