Heart rate zones explained: what zone 2 means for everyday exercise

Spring is when the running shoes come back out. Fun runs and marathon weekends fill the calendar, the evenings are getting lighter, and suddenly everyone at work seems to be talking about "zone 2".

If you've wondered what heart rate zones actually mean, here's a plain-English explanation: what they are, what zone 2 feels like, why your own numbers won't always match a chart, and how the Thrive Health Band shows your zones without asking you to stare at your wrist.

What heart rate zones are

Your heart rate rises as you work harder. Heart rate zones split that rise into bands, so you can describe how hard a session was.

Most zone systems start from an estimate of your maximum heart rate. The Victorian Government's Better Health Channel gives the common formula, 220 beats per minute minus your age, and notes that because it's an estimate, it should be used with caution.

A common five-zone setup looks like this. Thrive uses the same five zones and numbers them Z1 to Z5 in the app:

Z1: about 50 to 60 per cent of your estimated maximum. Very easy, like a gentle walk.
Z2: about 60 to 70 per cent. Easy and steady; you can still hold a conversation.
Z3: about 70 to 80 per cent. Moderately hard; talking takes more effort.
Z4: about 80 to 90 per cent. Hard; a few words at a time.
Z5: above 90 per cent. Close to flat out, for short bursts only.

Better Health Channel describes moderate intensity as 50 to 70 per cent of your maximum, which takes in Z1 and Z2.

What zone 2 feels like

You don't need numbers to find zone 2. Better Health Channel's talk test is a simple check: if you can talk comfortably but couldn't sing, you're working at a moderate intensity. If you can only manage a few words before you need a breath, you've moved into vigorous territory.

Zone 2 is the "comfortably talking" end of things. It's the brisk walk where you can still chat, or the easy jog that feels like you could keep going for a while. That's a big part of its appeal: it's gentle enough to do often, and it doesn't leave you wiped out for the rest of the day.

You don't need to live in one zone

It's easy to read about zone 2 and decide every session has to sit there. It doesn't. The Australian Government's physical activity guidelines for adults recommend 30 minutes or more of moderate to vigorous activity on most days, plus muscle-strengthening activities on two or more days a week. A good week can include easy walks, a harder session or two, some strength work and plenty of rest.

If you're building towards a fun run, keeping most of your sessions easy can make it more likely you'll still enjoy running by race day. If you're just starting out, our piece on starting running gently, from couch to 5k is a kind place to begin.

Why your numbers won't always match a chart

Charts are a starting point, not a verdict. Better Health Channel lists a range of things that can raise your heart rate, including hot weather, caffeine, the time of day, hormone changes, stress or anxiety, smoking and some medicines. On the first warm days of spring, the same easy jog can show a higher heart rate than it did in winter, and that's not unusual.

That's why your own pattern over weeks says more than any single session. If an easy run starts showing a slightly lower heart rate at the same pace over a couple of months, that's something to notice. If one session looks high, think about what else was going on that day.

Better Health Channel also notes that some medicines can change how your heart rate responds to exercise. If that might apply to you, ask your GP which way of judging effort suits you best. The talk test is a handy backup either way.

How Thrive shows your zones

The Thrive Band has no screen, so there's no number flashing at you halfway up a hill. It measures your heart rate through the day, and the Thrive app does the sorting for you.

Heart Rate Zones. The Activity tab shows how many minutes you spent in each of five zones, Z1 to Z5, across your waking hours, and your workouts show zone time too. Thrive sets your zones from an age-based estimate of your maximum heart rate.
Workouts and GPS. Thrive tracks walks, runs and rides with GPS through your phone, alongside workouts, plans and training programmes if you'd like some structure.
Today's Load and Today's Vitality. Today's Load gives you a sense of how much your body has done. Today's Vitality, a score from 0 to 100, brings sleep and recovery, your heart, your load and your mood together in one place.
Your nights. Thrive shows your sleep, sleep stages and resting heart rate, and the Band measures your HRV itself. Our explainer on HRV covers what that number means.
Your own normal. Thrive learns what's usual for you across nine areas of your health, so you can compare this month's easy runs with your own history rather than a chart.

You can also ask Ask Thrive questions in everyday language, such as "How has my resting heart rate looked this month compared with my usual?" or "How has my resting heart rate looked since I started running three times a week?"

If you train with someone, Thrive Loops lets you share selected information with a participating trainer, health professional or someone you trust. You decide what to share and with whom, and you can change or revoke access at any time.

Taking it to your GP

Heart rate zones are a way to describe effort, not a health check. What Thrive shows isn't a diagnosis, and Thrive isn't designed to tell you that something is wrong.

Better Health Channel suggests seeing your doctor before starting a new exercise program if you have a medical condition, are over 40 or haven't exercised for a long time. If you feel chest pain or pressure, dizziness, or extreme breathlessness while exercising, stop and get medical help. In an emergency, call triple zero (000).

For a routine visit, you can open the Thrive app and show your GP your activity and resting heart rate over recent weeks, and use Ask Thrive to put your questions into words beforehand. Our piece on getting ready for a GP appointment with Ask Thrive walks through it.

Before you buy

You'll need a compatible iPhone or Android phone, because the Thrive app is on the Apple App Store and Google Play, in Australia and eight other countries. The app stores are only for downloading the app, though; they aren't where you buy the Band or a Plan. You can buy at thrivehealthband.com, or at a participating World Gym Australia location or health and wellness clinic.

The Thrive Health Band is A$660 for the first year under the launch offer (usually A$740). That includes the Band, which is yours to keep, and 12 months of the Thrive by Optihealth app, My Health on the web, Health Fingerprint, Ask Thrive, Thrive Loops and your data, paid once upfront. Prices are in AUD and include GST. Free Australia-wide shipping during the launch offer (usually A$14.99).

Nothing renews automatically. After your first year, you can get a new band plus 12 more months for A$660, or keep your band and renew the Thrive Connected Plan for A$240 a year (A$20 a month).

You're also covered by a 12-month Thrive Care Warranty, and consumer guarantees under Australian Consumer Law always apply. See Returns if something is wrong with your purchase.

Common questions

What is zone 2?

In the five-zone setup Thrive uses, zone 2 (Z2 in the app) is about 60 to 70 per cent of your estimated maximum heart rate. It feels easy and steady: you can still talk in full sentences.

Do I need to know my exact maximum heart rate?

No. Age-based formulas are estimates, and the talk test is a simple way to check your effort without any numbers.

Does Thrive show heart rate zones?

Yes. The Thrive by Optihealth app shows your minutes in each of five zones, Z1 to Z5, on the Activity tab, through the day and in your workouts.

For more answers, see Questions.