What are Heart Rate Zones? Here’s a Quick 411.

What do you think of when you hear a trainer tell you to do cardio? I don’t know about you, but I immediately start trying to figure out what they mean. For most, the term “cardio” is such a generic term that it means nothing and everything all at once. The worst part is, that the more you hear it, the less your brain even realizes the lack of information it is receiving.

But what if there was a common language for cardio? There is, and that’s where heart rate zones come in!

Five heart rate zones help us figure out how hard we are working, what kind of fuel we are burning, and how long to work out. Depending on the heart rate zone, your body burns either fat or sugar. Did you know that burning sugar for too long can make you crave sugar? That’s probably not what anybody wants.

So, what happens if you don’t know your heart rate zones? You could be missing out on getting the results you want!

Watch the video below for a seven-minute primer on heart rate zones.

Here’s a quick overview of the five heart rate zones.

Zone 1 - Easy pace. On a 1-10 (10 is hardest) scale it feels like your working between 1 and 4. Zone 1 is good for recovery, either recovery workouts or recovery between segments of more intense work within a workout. The body burns the most fat here, but also the fewest calories.

Zone 2 - Moderate pace. Should be a little more challenging, but if you were talking to someone you would be saying full sentences and not out of breath. 4 to 6 out of 10. Zone 2 is good for building mitochondria, which increases the aerobic base. This is a primarily fat-burning zone. About 80% of cardiovascular exercise should be done in Zones 1 & 2.

Zone 3 - Faster pace.  You're pushing yourself a little more. If you were talking to someone, the sentences become a little shorter and you're a little out of breath. 7 out of 10. Zone 3 builds exercise tolerance and helps us develop endurance. The body uses a bit more stored sugar as it starts to approach the anaerobic threshold (AT). About 12% of Cardiovascular exercise should be done in Zone 3.

Zone 4 - Difficult pace. Out of breath. 1–2-word sentences. 8-9 out of 10. Zone 4 helps us develop speed, strengthens the heart, and further improves our ability to push ourselves. The body is above its AT and is now burning sugar as a primary fuel source. There is a benefit because the body will burn additional fat in the hours after exercise is stopped. For most people, 8% of cardiovascular exercise time should be spent in zones 4 & 5.

Zone 5 - You might feel like you're dying. Can't speak because you have to breathe instead. 10 out of 10. Zone 5 helps us develop power and push our maximum output a little bit further. Here, the body is burning tons of calories, but zero of them are coming from fat.

that’s a very brief overview, and there’s a lot more to learn about heart rate zones, including how to find yours. Want to know more? Check out this blog post for more.