What is Zone 2 training?

Zone 2 is the effort where you can still talk, but you'd rather not. Building an aerobic base takes a lot of easy miles, and Zone 2 is what keeps them easy enough to pile up, week after week. That's what it buys you: volume you can absorb, quicker recovery between hard days, fewer injuries, and hard days you can run hard. Your heart needs about 150 minutes a week of moderate exercise, and Zone 2 is the kind you can keep up.

How do you calculate your Zone 2 heart rate?

Zone 2 sits 60–70% of the way from your resting heart rate to your max. That span is your heart rate reserve, and the Karvonen formula runs on it: target HR = resting HR + 60–70% × (max HR − resting HR).

You need two inputs.

• Resting heart rate: measure on waking, before getting up, averaged over several days; the average your wearable reports is fine.
• Max heart rate: the highest reading from a genuinely maximal effort within the last year, a hard race finish or a max-effort field test.

Without one, 220 minus your age is the fallback, and it's the default your watch already uses. It carries individual spread of roughly plus or minus 10–12 BPM at one standard deviation. It's a starting point to replace with observed data, not a fact about you.

Many watches apply the same 60–70% to max heart rate instead. If your watch's Zone 2 doesn't match the numbers above, that's why:

Is Zone 2 60–70% of max heart rate or heart rate reserve? Both, and that's the problem. The same 60–70% gets applied to two different formulas, and they disagree by about 20 BPM. Use heart rate reserve, which accounts for your resting heart rate.

Is the MAF 180-minus-age formula accurate?

It depends on inputs it never asks for. The MAF formula takes your age and training history and nothing else. It never sees your measured max or resting heart rate, so where it lands against a measured Zone 2 range varies by runner.

Phil Maffetone's published formula: subtract your age from 180, then adjust once. Subtract 10 if you're recovering from major illness, in rehabilitation, on regular medication, or chronically overtrained. Subtract 5 if you're injured, regressed or not improving, inconsistent, or just starting or returning. Make no change if you've trained consistently, at least four times a week, for up to two years without those problems. Add 5 after more than two years of consistent, injury-free, improving training.

The result is one number, a maximum aerobic heart rate. It's a ceiling to train under, not a range, so MAF and Zone 2 aren't the same thing even when their numbers happen to agree.

We use MAF as a cross-check on the Karvonen range rather than a replacement for it, because the range is built from your measured numbers and the ceiling is not. If your MAF number lands far outside your Karvonen range, recheck your inputs before trusting either.

What should Zone 2 feel like?

Full sentences yes, a speech no. That's the talk test, the coaching convention for this intensity: you could answer a question in complete sentences without gasping, but you wouldn't volunteer a monologue. It's a sanity check against your sensor, not a replacement for heart rate.

If holding the zone means slowing way down or walking stretches, that's where most runners start, and the pace you can hold inside the zone rises as the base builds.

Heart rate tends to climb over a long run even at the same effort; the climb is called cardiac drift. Hills and heat both push heart rate up at the same effort, so the same zone means a slower pace on climbs and hot days.

How do you track Zone 2 on Apple Watch, Garmin, Polar, or Whoop?

Every sports watch shows you a live heart rate, and some let you set custom zones and display the current one mid-run. The problem they all share is that holding the zone means watching your wrist or staring at your phone, and Zone 2 only works if you stay in it. Checking over and over pulls you out of the steady rhythm these runs are for. RunBeat takes the monitoring off your wrist and off your screen, from an Apple Watch or any Bluetooth heart rate monitor, so you set the zone and never look at either:

Zone Training in RunBeat RunBeat tells you to speed up or slow down to stay in zone, right over your music or podcast.

A Garmin watch works as a Bluetooth heart rate monitor once Broadcast Heart Rate is turned on, a setting on the watch itself.

How does Zone 2 fit with intervals and harder training?

Zone 2 is the base of the week, not the whole week. The harder work sits on top: threshold runs, and VO₂ max intervals like the Norwegian 4x4. The base is what makes that work absorbable, with recovered legs between hard days and easy days easy enough that the hard days can be hard.

Iñigo San Millán, the physiologist who put Zone 2 on the map for most runners, includes work at and above threshold in the training he describes, alongside the easy volume. Doing only Zone 2 leaves that work undone.

A Zone 2 session typically runs 45 to 75 minutes.

If the harder training you're building toward is a HYROX race, the base works the same but the racing doesn't. Racing HYROX is running under station fatigue, where a zone stops separating going too hard from going correctly.