Zone 2 training: how to find your zone 2 heart rate, and why lifters need it too

Zone 2 is the most hyped boring thing in fitness. Podcasts call it a longevity cheat code. Lifters call it the thing that steals their gains. Runners do it too fast and call it zone 2 anyway.

The truth is less dramatic and more useful. Your zone 2 heart rate is the band where you can work for a long time, recover quickly, and come back tomorrow. That's it. It's the base of almost every serious endurance program, and it's the cardio a lifter can add with the least downside. Here's what zone 2 cardio is, how to answer "what is my zone 2 heart rate", and how to fit it around a barbell, whether you plan it yourself or use a running coach app.

What is zone 2 cardio?

Zone 2 is the second of five intensity zones. In the model we use across this blog it's 60–70% of your max heart rate, roughly 3–4 out of 10 on effort. If you'd rather not do the math by hand, work out your zones here. For the full five-zone picture, including what zones 1, 3, 4 and 5 are for, start with how heart rate zones work.

Physiologically, zone 2 sits below your first lactate threshold: the point where blood lactate starts climbing above resting levels (Faude, Kindermann and Meyer, 2009). Below it, you can keep going for a long time without accumulating much fatigue. Research on how well-trained endurance athletes train describes the bulk of their sessions at this kind of low intensity, at or under about 2 mmol/L of blood lactate (Seiler, 2010).

What zone 2 feels like:

• ›You can talk in full sentences. Not gasping between words.
• ›Breathing is noticeably up, but controlled. Nose-breathing might even be possible.
• ›It feels almost too easy for the first 20 minutes. That's correct.
• ›You finish feeling like you could do it again.

Zone 2 isn't a running thing. It's an intensity. Cycling, rowing, incline walking, the ski erg, swimming: if your heart rate and effort are in the band, it counts.

What is my zone 2 heart rate?

There are three ways to find it, from fast and rough to slow and accurate.

Option 1: an age formula

Estimate your max heart rate, then take 60–70% of it.

• ›220 − age is the old rule of thumb.
• ›208 − 0.7 × age comes from Tanaka, Monahan and Seals (2001), who found the older formula underestimates max heart rate in older adults.

These are estimates of an estimate. Your actual max can be well above or below the formula. Treat the table as a starting point.

Option 2: the talk test

Run, ride or row and try to speak a few sentences out loud. If you can talk comfortably, you're at or below your first threshold. If speech becomes uncertain, you're right around it. Researchers have used this exact approach: the point where talking stops being comfortable tracks the ventilatory threshold, and the talk test can be used on its own to regulate training intensity (Woltmann et al., 2015; Bok, Rakovac and Foster, 2022).

The talk test is free, works for every machine in the gym, and doesn't depend on an age formula. It pairs well with effort ratings: zone 2 is roughly RPE 3–4, which is how hard a session should feel when the goal is volume, not suffering.

Option 3: a test

A lab test with blood lactate or gas analysis gives you an actual first threshold and the heart rate that goes with it. It's the most accurate route and the least necessary for most people. If you have the data, use it. If you don't, options 1 and 2 cross-checked against each other are plenty.

When the formula and the talk test disagree

Believe the talk test. If your "zone 2" by formula leaves you unable to finish a sentence, the formula is wrong for you. If you can chat freely at the top of your formula zone 2, your max heart rate is probably higher than estimated, and that's fine too.

What zone 2 actually does (and doesn't)

What it does: it lets you accumulate a lot of aerobic work at a low recovery cost. Fitter endurance athletes handle easy intensities with less strain. In one comparison, professional endurance athletes oxidized more fat and built up less blood lactate at the same submaximal intensities than moderately active people (San-Millán and Brooks, 2018). That's a cross-sectional comparison, not proof that zone 2 alone made the difference, but it's the kind of fitness easy volume is meant to build.

What it doesn't do: magically burn body fat. Fat oxidation during exercise does peak at moderate intensities. In Achten, Gleeson and Jeukendrup (2002), trained cyclists hit their maximal fat oxidation around 64% of VO2 max, or about 74% of max heart rate, which by our zone table is the top of zone 2 and into zone 3. But burning a higher proportion of fat during a session isn't the same as losing more body fat over months. That depends on far more than which fuel you used on Tuesday.

It also doesn't replace hard training. Zone 2 builds the base. Faster running, VO2 max and race performance need some work in zones 4 and 5 on top of it.

Why lifters need zone 2 too

This is where zone 2 earns its keep for people who mostly lift.

It barely interferes with strength or size

The fear is that cardio eats gains. The best current evidence says the effect is smaller than gym folklore claims. An updated meta-analysis of 43 studies found concurrent aerobic and strength training didn't compromise maximal strength or muscle growth compared with lifting alone; explosive strength was the exception, especially when both were done in the same session (Schumann et al., 2022).

An older meta-analysis found interference grew with the frequency and duration of endurance work, and was larger for running than for cycling (Wilson et al., 2012). The newer one didn't find a difference by modality. Either way, the practical answer is the same: moderate amounts of easy cardio, kept away from your heaviest sessions, are a small cost. Running and muscle loss is mostly a programming problem, not a physiology sentence.

It's the cheapest conditioning you can buy

Lifting programs leave your aerobic system mostly untrained. Zone 2 fills that gap without leaving you sore for leg day, which is the core principle of how to combine running and lifting: the easy work goes anywhere, the hard work gets placed carefully. If you want the full evidence picture, including the exceptions, that's the concurrent training research side of things.

How to fit it in

For a lifter adding zone 2 for the first time:

Two practical rules: keep zone 2 away from the 24 hours before your heaviest lower-body session if your legs feel it, and cut it back before you cut lifting when you're short on recovery. Morning numbers like resting heart rate and heart rate variability can tell you when recovery is running behind.

How much zone 2 do you need?

There's no magic minute count. Some coaching conventions:

• ›Beginners: two or three 20–40 minute sessions a week is a solid start. If you're new to running specifically, how to start running covers walk-run progressions that naturally land in this zone.
• ›Hybrid athletes: most of your running volume should be easy. A common target, borrowed from how endurance athletes train, is around 80% of sessions easy (Seiler, 2010).
• ›Lifters adding cardio: 60–120 minutes a week spread over two or three sessions is a reasonable place to start, adjusted to how your lifting responds.

Build up gradually. Add time before you add speed.

The most common zone 2 mistakes

• ›Going too hard. The most common one by far. If you're breathing too hard to talk, it isn't zone 2.
• ›Trusting a default max heart rate. Most watches start you on an age formula. Cross-check with the talk test.
• ›Making every session zone 2. It's the base, not the whole house. Keep some hard work in the week.
• ›Confusing zone 2 with zone 1. Recovery runs are slower still, mostly zone 1. Zone 2 is easy, but it's still training.
• ›Chasing heart rate on hot days. Heat pushes heart rate up at the same effort. Slow down rather than fighting it.

How exrsz handles zone 2

exrsz builds a periodized plan from your goal, schedule, level and equipment, with easy aerobic sessions as the base. It balances them against your lifting in one plan so they don't land where they'll hurt your heavy days, adapts the week to how you actually trained, and reshuffles missed sessions instead of stacking them up.

FAQ

What is zone 2 cardio?

Zone 2 cardio is easy, steady aerobic exercise at about 60–70% of your max heart rate, where you can still talk in full sentences. It can be running, cycling, rowing or incline walking.

What is my zone 2 heart rate?

Estimate your max heart rate (for example 208 − 0.7 × age) and take 60–70% of it. Then cross-check with the talk test: if you can't speak comfortably, slow down.

Does zone 2 cardio kill muscle gains?

Current evidence says moderate concurrent cardio doesn't compromise maximal strength or muscle growth, though explosive strength can be slightly blunted, especially when both are done in the same session. Keep it easy and away from your heaviest days.

Is zone 2 the fat-burning zone?

Fat oxidation peaks at moderate intensities, around the top of zone 2 and into zone 3 in lab studies. But the fuel you burn during a session isn't the same as long-term fat loss.

How long should a zone 2 session be?

For most people, 30–60 minutes is a practical range. Beginners can start at 20 minutes and build.