What Is Cardio Zone 2 and How Should I Actually Do It?
Low-intensity cardio, sometimes called LISS or “zone 2,” is an underrated form of exercise. It’s finally coming back into fashion after years of absence while HIIT and lifting-only exercises dominated. But what is cardio zone 2? Why should you do this? And how do you know if you’re doing it right?
What is Zone 2 training?
Zone 2 training is cardio performed at a constant low intensity. It’s useful for aerobic training (so you can run faster), anaerobic training (helps you recover faster between reps and sets or between intervals), and is an effective way to burn calories without getting tired .
“Zone 2” is a term taken from the five-zone heart rate training system, and the same concept is also known by other names and metrics. For runners, this is “easy pace” or “slow pace for long distances.” For cyclists, this corresponds to zones 2 and 3 of the seven-zone mechanical power system . In other sports such as swimming and rowing, they are often referred to simply as “light” or “low-impact” exercise.
The great thing about zone 2 workouts is that they are relatively slow and done at a steady pace. You’ll be aiming for your heart rate to be around 70%, but that doesn’t mean you should do intervals at 90% and then rest at 50%. This means maintaining a level of 70% throughout the entire workout. Zone 2 cardio can be performed using any sustained, repetitive movement. Popular methods include running, cycling, swimming, rowing, brisk walking, brisk walking, or riding an elliptical machine. (Walking can be helpful if you’re new to exercise; as you get better, you may need to choose a more challenging form of exercise .)
To be clear, it’s still work —it’s not the same as sitting and relaxing—but it should feel like you could keep working forever if you wanted to. You don’t stop a zone 2 session when you’re tired, you stop because you scheduled a 30, 45 or 60 minute session and your time is up.
What are the benefits of zone 2 cardio?
Working in zone 2 builds your aerobic base. When you do cardio at such an easy pace, your body adapts by increasing the number of capillaries (tiny blood vessels) to more efficiently deliver oxygen and nutrients to your muscles. You get more mitochondria to power each muscle cell (you have thousands of mitochondria per cell) and you produce more enzymes that convert food into usable energy. Your heart and lungs become more efficient at absorbing oxygen and transporting blood to your muscles, and your muscles become able to store more carbohydrates (in a form called glycogen), so more of the carbohydrates you eat are ready to go. jogging or traveling.
For runners, Zone 2 work, often called “easy pace,” should make up the majority (some say 80%) of your weekly mileage. The fitness you achieve from easy running is what allows you to benefit and recover from harder efforts like interval training.
For people whose primary sport is more strength-oriented (like me), zone 2 cardio strengthens the same body systems that help us recover between sets and even between reps. This increases our productivity, allowing us to get more work done overall. If you eat enough, adding cardio to your daily routine will allow you to do more work in the gym, not less. (And no, cardio doesn’t kill your results .)
And for people who simply exercise for health, Cardio Zone 2 is the ideal “moderate” exercise that we should all be doing at least 150 minutes a week . It’s good for the heart, and even people with medical conditions that limit their ability to exercise can often do low-intensity cardio exercise safely . (Of course, check with your doctor to be sure.)
It is important to note that zone 2 training is very low fatigue . More time-efficient forms of cardio and conditioning like HIIT, hill sprints, or CrossFit WODs are great for your aerobic fitness, but these workouts need to be high-intensity to work, and then you’ll poop. They are good in small doses, but they need to be taken in small doses.
On the contrary, working at an easy pace is practically free. You can do easy zone 2 workouts every day in addition to your regular workouts and feel good. Once you get used to it, you will be able to do zone 2 work on your “rest” days without defeating the purpose of the rest day. If you have the time for it, it’s kind of a cheat code for achieving aerobic results.
How do you know if you are in zone 2?
The best way to know if you’re in zone 2 is to pay attention to your efforts and how they feel. Even though “zone 2” is determined by heart rate, I don’t recommend that beginners calculate it by heart rate percentage first. Unless you’ve actually pushed your heart rate up to your maximum effort level and know what that number is, you won’t actually know your maximum heart rate .
Instead, let’s talk about how it should be. On a scale of 0 to 10, where 0 is nothing and 10 is sprinting, low-intensity cardio is about a 3. You’re working out, but not very hard.
This pace is conversational , and is sometimes called the “conversation test”. If you could tell a friend about your day while working out, you’re probably on the right level. This doesn’t mean spitting out a few words here and there, but speaking in complete sentences without getting out of breath. If you find yourself stopping to catch your breath or feel like you need to take a break, you’re overdoing it.
However, it shouldn’t be too easy: Zone 2 is more like a brisk walk or light jog than a leisurely stroll. If you stop, you should feel like you’ve taken a break from something. Maintaining the pace requires some work and focus.
Run
Runners often have trouble with this as the line between walking and running is sometimes too high to maintain an easy pace while running if you are a beginner. The next best option is to jog as slowly as possible, and when you feel out of breath, switch to a brisk walk. For some people, brisk walking throughout your workout is an ideal zone 2 workout. As you get fitter, light jogging will be possible.
Here’s a real-life example of how to maintain a zone 2 pace: If I’m going for an easy run, I start at a nice, easy jog pace. But I live in a hilly area, so pretty soon I’ll be walking up a hill and I’ll notice my breathing getting heavier. At this point I switch to power walking. Running on flats and walking uphill is a great way to maintain a consistent level of effort, rather than accidentally turning an easy run into a hill sprint.
A ride on the bicycle
Cyclists often measure their training using a seven-zone system, which is based on how much power, in a physical sense, you put into your bike’s gears. These are called Coggan Power Zones , and cycling training systems like Zwift and Peloton use the same basic idea. To calibrate these zones, you’ll take an FTP (functional threshold power) test—essentially a 20-minute race against yourself. From here, you (or your workout app) calculate power ratings for your zones.
Zones 2 and 3 in this system generally correspond to our “zone 2” cardio. (By the way, your heart rate at the end of the FTP test will be pretty close to your maximum heart rate if you really went all out.) If you’re training with both a heart rate monitor and a bike power meter at the same time, don’t worry if they don’t match exactly. Riding in power zones 2 and 3 will satisfy your low-intensity cardio needs, even if your heart rate starts in zone 1 and skyrockets to zone 3 by the end.
Miscellaneous Cardio
For other forms of cardio, go by sensation or heart rate if you actually know your heart rate percentages. When you’re on the elliptical, rowing, or airbike, you should feel like you can easily continue a conversation and stop because time is up, not because you’re running out of gas.