What is Zone 2? How to work out your heart rate range

Zone 2 is one of those terms you can’t get away from in endurance training these days. Runners do their Zone 2 runs, cyclists ride their long days in Zone 2, and your smartwatch tells you at the end of every session how many minutes you spent there.

If you’re coming across it for the first time, it can be a bit confusing. Once heart rate percentages, maximum heart rate, different ways of calculating it and each watch’s own zones come into it, a simple idea can start to look far more technical than it needs to be.

The core idea is actually very simple: Zone 2 is a controlled aerobic effort you can keep up for a long time. Your breathing picks up, but you don’t run out of breath. You can feel you’re working, but you’re not counting down the minutes until it’s over. You could hold a few sentences of conversation with the person next to you. In short, Zone 2 isn’t very easy, and it isn’t “now I’m doing a tempo run” either. It sits right in between. And that’s exactly where most people go wrong: the point of Zone 2 training is not to go as fast as you can.

What does Zone 2 mean?

Exercise intensity is usually split into five zones based on heart rate. At its simplest, you can think of it like this:

Zone	Intensity	How does it feel?
Zone 1	Very light	Easy walking, warming up
Zone 2	Light to moderate	Comfortable but active
Zone 3	Moderate	Talking starts to get harder
Zone 4	High	A hard, demanding pace
Zone 5	Very high	Close to all-out effort

With the widely used maximum heart rate method, Zone 2 is taken as roughly 60–70% of your maximum heart rate. The important detail is that these percentages aren’t a fixed rule. Different watches, apps and training systems can define the zones slightly differently. The Zone 2 you see on a Garmin screen may not have exactly the same limits as Zone 2 on another platform. So rather than just looking at the colour on your watch, it’s worth knowing how that zone was worked out.

Why is everyone talking about Zone 2?

If you want to build your endurance, not every session needs to be hard. A big part of long aerobic work can be done without keeping your body under constant high stress. That’s a large part of the appeal. You can keep going for a long time, you don’t finish feeling completely drained, and training again the next day is usually easier. The recovery you need after a hard session isn’t the same as what you need after Zone 2. Over time, you build your capacity to keep moving for longer. That’s why you see a lot of work at this intensity in sports where endurance matters, like running, cycling, rowing and skiing — and it’s usually the backbone of the base training phase at the start of a season.

It’s worth a quick word here about the “fat-burning zone”. Online, this zone is sometimes sold as an almost magic formula for burning fat. It’s true that at low and moderate intensities, fat can make up a bigger share of the energy you use. But the heart rate zone you train in doesn’t decide weight loss on its own. How much you move in total, what you eat, how your training is structured and how long you can keep it up are still much bigger parts of the picture.

How do you work out Zone 2?

You’ll come across two methods most often:

Working out Zone 2 from maximum heart rate

This is the easiest method. First you find your estimated maximum heart rate. The best-known formula is:

220 − age

So if you’re 40:

220 − 40 = 180

Your estimated maximum heart rate comes out at 180 bpm. If we take Zone 2 as 60–70%:

• 180 × 0.60 = 108
• 180 × 0.70 = 126

That puts your estimated Zone 2 at 108–126 bpm.

It couldn’t be easier to calculate. The catch is that not everyone of the same age has the same real maximum heart rate. Two 40-year-olds can have very different maximums. So the 220 − age formula isn’t a personal measurement; it’s an estimate to get you started — the American Heart Association’s target heart rate chart is built on the same rough estimate too. That’s exactly where the second method comes in.

What is the Karvonen method?

The Karvonen method doesn’t just look at your maximum heart rate; it takes your resting heart rate into account as well. First, you work out your heart rate reserve:

• Maximum heart rate − resting heart rate = heart rate reserve

Then you apply the intensity percentage you want to that number and add your resting heart rate back on. Let’s stick with the same example:

• Maximum heart rate: 180 bpm
• Resting heart rate: 60 bpm
• Heart rate reserve: 180 − 60 = 120
• For 60%: 120 × 0.60 + 60 = 132
• For 70%: 120 × 0.70 + 60 = 144

With this method, the same person’s Zone 2 comes out at 132–144 bpm. And what did we get with the first method? 108–126 bpm. That’s no small gap. It’s one of the reasons you find such different numbers when you search “what should my Zone 2 heart rate be?” — not everyone uses the same calculation.

Zone 2 calculator

Enter your age, your resting heart rate and, if you know it, your real maximum heart rate to work out your own estimated training zones. You’ll find that last one in the Adjust maximum heart rate section of the calculator.

Seeing the two results side by side in the calculator is particularly useful:

• Zone 2 by percentage of maximum heart rate
• Zone 2 by the Karvonen method

That way you can see for yourself why one method gives you something around 120 bpm and the other something closer to 140. If you just need the numbers, the same tool also lives on the Target Heart Rate Calculator page.

Which one should I use?

There isn’t a single method we can tell you to use, full stop. If you’re new to training, the simple maximum heart rate percentage is a good place to start. If you track your resting heart rate regularly, the Karvonen method gives a slightly more personal result. And if you know your real maximum heart rate from a lab test or a reliable field test, the calculation naturally becomes more meaningful.

But don’t get too hung up on the numbers. Weigh up the calculated heart rate together with how the session actually feels — an effort scale like RPE exists for exactly that. If your watch says you’re in Zone 2 but you need to catch your breath after a few words, there’s not much point in just believing the watch. The opposite is true too: your watch flicking into Zone 3 for a moment doesn’t mean the whole session is ruined.

The talk test: can you find Zone 2 without looking at your watch?

Mostly, yes. Especially at the start, the talk test is one of the most useful tools you’ve got. In this zone you should be able to keep a normal conversation going without breaking it up. You’re breathing faster than at rest, but you’re not fighting for air after a few words.

If you can say something like this to the person next to you:

“It’s warmer than I expected today, let’s slow down a bit.”

you’re probably about right. If it’s starting to come out like this:

“It’s… really… warm… today…”

the intensity has probably crept up. It’s a very simple method, but it works. And on top of that, your heart rate doesn’t behave the same way at every time of day or in every condition.

Why does my heart rate change at the same pace?

Last week you ran at 6:30/km with a heart rate of 135; today, at the same pace, your watch says 147. The first thought is usually: “Is something wrong?” Not necessarily. Your heart rate isn’t only affected by your fitness. Heat, humidity, dehydration, fatigue, stress, caffeine, sleep, the gradient of the route and even some medication can all change the number you see. So on some days, your aim should be to keep the same effort rather than the same pace:

• On a hot day, you can run slower.
• On a hill, you can switch to walking.
• On the bike, you can drop down a gear.

I think this is one of the hardest things to accept about Zone 2 at first. If you’re used to watching your speed when you run, slowing down can feel like you’re having a bad session. But what you’re trying to measure here isn’t speed; it’s intensity.

What is a Zone 2 run?

A Zone 2 run is an easy run where you keep your heart rate or effort at a low to moderate aerobic intensity. But especially if you’re just starting out, it doesn’t have to be one continuous run. For example, you could go:

• 5 minutes running
• 1 minute walking
• 5 minutes running
• 1 minute walking

Some people even jump into Zone 3 the moment they start running. If that’s you, there’s not much point forcing yourself into an awkward pace that’s a bit faster than walking and a bit slower than running just because you’re “doing a Zone 2 run”. Mixing running and walking is completely normal. And it’s one of the things you want to change as your fitness improves anyway. If you’re running at 8:00/km at a given heart rate today, a while later you might see 7:30/km at the same heart rate — tracking that difference with the pace calculator makes your progress tangible. That’s where a lot of the improvement shows up.

What is Zone 2 walking?

Zone 2 isn’t only for running. A brisk walk can make a perfectly good Zone 2 session too. It’s a real option if you’re new to exercise, coming back to running, carrying a higher body weight or having a recovery day. If your heart rate doesn’t rise enough on the flat, you can walk a bit faster or add a gentle incline. That’s one of the reasons brisk walking on a treadmill with the incline turned up is so popular. Don’t get too caught up in what the movement is called; running doesn’t automatically make it a better aerobic session.

What does Zone 2 look like on the bike?

On the bike, Zone 2 usually shows up on long, controlled rides. You’re pedalling and you can feel you’re working, but there’s no constant heavy pressure in your legs. When a climb comes, you may need to drop a gear to keep your heart rate in check.

There’s also an important difference from running here: the heart rate numbers you see on the bike don’t have to match the ones you see when you run. So rather than applying the same heart rate targets to every sport on your watch, you’ll get more out of watching your own data over time. The same goes for cyclists who use a power meter. On the bike, Zone 2 can be tracked by power zones as well as heart rate. But that opens up a whole other topic.

How does Zone 2 feel on the rowing machine?

Zone 2 on a rowing machine can be a little misleading at first, because your legs, core and arms are all working at once. It can feel very comfortable for the first few minutes, then a few minutes later you see your heart rate slowly creeping up.

Rather than constantly pushing up your stroke rate, it makes more sense to find a comfortable rhythm you can repeat. If you try to produce maximum power on every stroke, you’ll be out of Zone 2 pretty quickly. Once you find the rhythm, though, it can turn into a really good aerobic session you can keep up for a long time.

Can you do Zone 2 on skis?

You can, but the answer depends on what kind of skiing we’re talking about. In a straight endurance discipline like cross-country skiing, Zone 2 training makes a lot of sense. Alpine skiing is a different story.

Between the gradient of the piste, short hard efforts, the descents, waiting for the lift and the breaks, your heart rate can be all over the place. So an approach like “today I won’t leave Zone 2 for 45 minutes” isn’t very realistic for alpine skiing. It probably makes more sense to read what your watch shows at the end of the day as your overall activity load.

How accurate is Zone 2 on a smartwatch?

A smartwatch is really handy here. But it’s not the referee.

For a start, the maximum heart rate your watch uses may be wrong. Secondly, you may not know which method it used to set your Zone 2 limits. And thirdly, optical heart rate readings from your wrist have their limits too. With sudden changes of pace, in very cold weather, when the watch sits loose on your wrist or in activities with a lot of arm movement, the reading can sometimes go astray.

So it’s better to read the “Zone 2” on your watch together with how the effort feels to you. If you’ve started taking heart rate training seriously, a chest strap is worth considering; the difference tends to show most in sessions with rapid heart rate changes, like intervals. How accurate a given sports watch is in each sport is another question altogether.

Do you need to keep checking your watch during Zone 2?

At first, you’ll probably look at it quite a lot. That’s normal, because you don’t yet know which speed or which effort matches which heart rate for you. But the goal isn’t to spend the rest of your life turning your wrist over every 15 seconds.

After a while, you start to notice things:

• You feel the rhythm of your breathing change.
• You recognise the point where talking starts to get harder.
• You get a better sense of the load in your legs.
• You learn the level of running where you think, “I could keep this up for a long time.”

And bit by bit, your watch stops being the one making the decisions and becomes a way of checking. I think that’s how it should be.

How much Zone 2 should you do?

There’s no single duration that fits everyone. Your training history, your sport, your goal and your total weekly training all change the answer. For someone just starting out, even a controlled 20–30-minute walk can be well worth it; for a long-distance cyclist, a Zone 2 ride might last several hours.

So don’t get too hung up on the hard-and-fast claims you often see online, like “Zone 2 only works if you do at least 60 minutes”. Especially if you’re just starting, making it a regular habit matters more. A few controlled aerobic sessions that fit your schedule will usually be more sustainable than one two-hour session a week.

Should every session be Zone 2?

No. Zone 2 is a really useful tool, but it isn’t the whole training system. If you want to get faster, you’ll need to go up to higher intensities from time to time. If you want to get stronger, you need resistance training. Different goals, like running economy, speed or threshold, call for different sessions.

It’s better to think of Zone 2 as one of the foundations of your endurance training. Foundations matter. But the foundations aren’t the whole house.

Is Zone 2 really too easy?

Plenty of people have the same reaction the first time they do Zone 2 on purpose: “Do I really have to go this slowly?” Sometimes, yes, you do. Especially if you’ve done every run at a moderate or hard pace for years, Zone 2 can feel surprisingly slow.

• You may need to walk when a hill comes.
• You may have to let another runner go past without chasing them.
• The pace on your watch might be a bit disheartening.

But if the point of that day isn’t to run fast, none of that matters. The really interesting part shows up a few weeks or a few months later. The heart rate you used to see at 8:00/km might start showing up at 7:30/km. On the bike, you might produce a bit more power at the same heart rate. A climb that used to leave you breathless might start to feel easier. It’s hard to see that progress at the end of a single session. It takes a bit of time.

Don’t make Zone 2 more complicated than it is

Think of a controlled aerobic effort you can keep up for a long time. Your breathing is faster, but it doesn’t get out of control. You can talk. You’re not constantly wondering when the session will end. Your watch can give you a heart rate range, and a calculator can show you a good starting point. Over time, you’ll learn for yourself which intensity really feels like Zone 2. I think that’s the healthiest way to approach it.

Don’t ignore the numbers completely. But don’t hand the whole session over to a single number either. Because the real point of Zone 2 isn’t seeing the right colour on your watch screen; it’s building an aerobic base that lets you keep moving, under control, for a long time.

Planning your race-morning warm-up around this kind of effort? How long your race-morning warm-up should be depends on the distance — a 5K calls for a different warm-up from a marathon.