Physiologists and coaches describe exercise intensity with heart rate zones. These zones are all relative to your maximum heart rate, which will vary significantly from person to person, and with age. We’ll help you find your maximum heart rate, and then calculate and use your training zones.
First Find Your Maximum Heart Rate

You may have read that your maximum heart rate can be estimated by subtracting your age from 220. This is better than nothing, but there’s such a good chance that the result will be wildly inaccurate that we can’t recommend it. You really should find your maximum heart rate through testing.

Get a go-ahead from your doctor, especially if you haven’t been doing much intense exercise lately. Finding your maximum heart rate is extremely high-stress.

You’ll need a reliable heart rate monitor that logs data. The standard method is to use a treadmill and to progressively raise the incline, However, a study done in Oslo found a simpler method that reliably raises the heart rate even higher.

This method also uses a treadmill. Warm up, and then run for 3 minutes at the maximum pace you can sustain for this time. Recover with 2–3 minutes gentle running. Then repeat the 3 minute maximal effort again, at the same pace as before. That’s it. Your heart rate should peak sometime before the end of the second 3 minute interval. It’s ok if you can’t complete the full second set, but you should try as hard as you can.

Ideally, your heart rate monitor should sample your heart rate every 5 seconds, or more frequently. The heart tends to reach its peak and then drop back down very quickly. See if this is a setting you can adjust. It’s also important that you be well rested, and thoroughly recovered from previous workouts.

All the training zones are calculated as percentages of your maximum HR.

Very Light: 50 to 60% MHR

This is the easiest training zone, suitable for warming up, cooling down, or recovery days. While in this zone, you should be able to carry on a normal conversation, or even sing along with the music on your headphones.

Light: 60 to 70% MHR

This training zone is ideal for extended endurance workouts. You should be able to speak in full sentences, but probably won’t be able to sing well. This intensity level works your aerobic system, but doesn’t demand extensive recovery the next day.

Moderate: 70 to 80% MHR

Many athletes naturally gravitate toward this intensity zone. Which is not ideal-you’ll get benefits from this exercise, but you’ll do better to spend more time either at higher or lower intensities. Coaches sometimes refer to this zone as “the mediocre middle.”

In the Moderate zone you’ll be able to talk, but probably only in shorter sentences.

Hard: 80 to 90% MHR

Somewhere in this zone, you’re likely to hit your anaerobic threshold, which is the intensity beyond which your muscles start to burn and you’ll have to slow down or stop within the next several seconds or minutes. Your anaerobic threshold will vary depending on your genetics, how well-trained you are, and to what degree you’ve done high-intensity training at or above the threshold. This is the intensity range for tempo training and short to moderate races (5K and 10K). In the Hard zone, you’ll have trouble saying more than a few short phrases before having to catch your breath.

Maximum: > 90% MHR

This zone is the province of high-intensity interval training. Training here offers the maximum benefit to your oxygen uptake, your anaerobic threshold, and your ability to quickly recover from short efforts. It’s also very demanding, both physically and mentally. Generally, you’ll only want to do one workout in this range per week. At the very most two. And you’ll need a recovery day afterwards, with much lower intensity activity. You’ll only be able to sustain efforts in this zone for ten seconds to two or three minutes, depending on how close to 100% you’re pushing yourself. You won’t be able to talk, but gasping, whimpering, and moaning are popular. We will post soon about how to structure high-intensity interval workouts.

How to Use This Knowledge

Once you know your maximum heart rate and your training zones, you’ll have a much easier time designing a training program, or following a program designed by someone else. While the zones are necessarily imprecise, they make it easy and repeatable to get into the correct general range for any given type of training. And they help you stay out of the wrong ranges, so you’ll be less likely to overtrain.

We hope you enjoy putting this knowledge to good use!