If you’re new to tracking your fitness with one of the best Apple Watches, or you’re wondering how to use the heart rate zones on your Apple Watch Series 8 or Apple Watch Ultra, we’ve got you covered.
Below, we’ll take a look at what the different heart rate zones on your Apple Watch mean, how they work, and how to manually edit them if you think they might be incorrect.
Heart rate zones refer to the number of times your heart beats per minute. While a lot of the best fitness trackers have incorporated heart rate zones into their fitness tracking for a while, Apple only introduced it to its products in the WatchOS 9 update last year.
Your heart rate zones are a percentage of your maximum heart rate (the maximum number of times your heart can beat per minute) and are automatically calculated based on the health data your Apple Watch has collected.
How to use heart rate zones on Apple Watch
It’s important to note, heart rate zones will only work on Apple Watch once you have inputted your date of birth, either in the Health app, or on your iPhone. Your maximum heart rate is calculated by subtracting your age from 220.
If your Apple Watch heart rate zones are set to "automatic," Apple will automatically update them using its ‘Heart Rate Reserve’ method. This basically means your maximum heart rate and resting heart rate are updated on the first day of every month, to ensure your data is up to date.
If, however, you’re switching from one of the best Garmin watches to an Apple Watch, you might already know your heart rate zones, and prefer to manually input them into your Apple Watch.
To do this, go to Settings, then Workout, then Heart Rate, then select Manual. You can then set your heart rate zones from 1-5 manually.
But what do the different zones mean and how can you use them in your training?
Zone 1: 50-60% of your maximum heart rate
This zone refers to very light activity. You will be able to talk in full sentences and could continue exercising in this zone for hours.
Zone 2: 60-70% of your maximum heart rate
This zone is an easy effort. You should still be able to talk in full sentences but will be breathing a little harder.
Zone 3: 70-80% of your maximum heart rate
This zone refers to moderate effort-level activities, and is often referred to as a ‘steady-state’. It’s a good zone to work in if you’re looking to build endurance. You’ll still be able to talk in full sentences, but it’s more difficult to do so, and you might need to take pauses.
This zone is important for building endurance. Other wearable devices might refer to it as a "fat burning zone," as research has found that when the heart beats between 64-76% of its maximum rate, the body burns fat as its primary fuel source. During harder efforts, the body’s primary fuel source switches to carbohydrates.
Zone 4: 80-90% of your maximum heart rate
This is a hard effort, like a running tempo session. It’s hard to talk, and while you’d be able to hold this for a while, it’s not comfortable. This is an important zone to train in if you’re looking to build speed and endurance. Your body will start using carbohydrates for energy.
You'll also continue to burn calories after you've finished exercising when you work out in zones 4 and 5 thanks to what's called Non-Exercise Activity Thermogenesis (NEAT). Read more about NEAT here.
Zone 5: 90%+ of your maximum heart rate
This is your maximum effort when your heart, lungs, and muscles are working as hard as possible. You’ll only be able to stay in this zone for a few minutes, you’ll be breathing heavily, and speaking more than a few words is difficult.
What are the benefits of heart rate training?
The benefit of heart rate training is that it helps you establish what’s right for you — your heart rate zones will be personalized to you, so it’s often an easier metric to look at compared to pace or cadence. It’s also a metric that’ll improve as you get fitter, so it’s one to keep an eye on.
Watching your heart rate can also prevent you from pushing yourself too hard on easier days. If you set out for a run and focus on staying in zones 2 and 3, you’ll ensure you’re not getting swept up and pushing yourself too hard on a day when you should be recovering.
On the other hand, it can also make you push yourself a little harder — if you’re working out to lose weight, staying in zone 1 might not get you the results you’re looking for.