What Are Heart Rate Zones? How to Use Them for Weight Loss

Understanding heart rate zones (or HR zones for short) is a great way to make the most out of your workouts.

Sometimes called cardio zones, the tiers are based on how many times your heart beats every minute, helping you gauge the intensity of exercise. Knowing what the zones are might help you optimize your workouts, ultimately boosting your cardiovascular health and potentially supporting weight loss.

Let’s explore how these zones work and how they can help you assess your fitness level. We also have tips for crafting a training plan that aligns with your weight loss and fitness goals. You’ve got this!

Let’s start with the basics. The Centers for Disease Control and Prevention (CDC) says to aim for 150-300 minutes (or two and a half hours) of moderate-intensity physical activity spread over a week. If you’re short on time, you could do 75-150 minutes of vigorous-intensity activity each week instead.

The CDC also suggests throwing some strength training into the mix a couple of days a week.

Though target heart rate zones vary from person to person, the American Heart Association says to aim for 50 to 60 percent of your maximum heart rate during moderate-intensity activity. During vigorous exercise, shoot for 70 to 85 percent of your maximum heart rate.

So, where do the zones come into play? Well, heart rate zones can help you understand these different intensity levels, making it easier to meet those weekly fitness goals.

Some models use three heart rate zones, while others use five. Either way, they’re separated to reflect various intensity levels.

For example, you might tap into a couple of heart rate zones within one workout session. All zones require proper fuel, but they burn through different fuel sources, like energy from carbohydrate or fat stores in your body.

The five heart rate zones to remember are:

• Zone 1: Light activity (e.g., walking) for warming up; burns fat

• Zone 2: Aerobic heart rate zone for improving cardiovascular health; supports fat metabolism

• Zone 3: Challenging but sustainable for about 20 minutes; taps into carbohydrates and proteins for fuel

• Zone 4: High intensity; best for short bursts; pushes your limits

• Zone 5: Peak effort; perfect for interval training; primarily uses carbohydrates for fuel

Keep scrolling for details.

Heart Rate Zone 1

You’ll most likely have a zone 1 heart rate during a warm-up or with very light physical activity, like going for a walk.

This zone is an essential part of a healthy lifestyle, especially if you’re just starting to get into exercise. Light-intensity workouts usually use fat as a source of fuel.

Heart Rate Zone 2

This cardio zone is often called the aerobic or endurance zone. Reached with low-intensity or moderate-intensity workouts, it’s your base level where you feel like your heart is pumping but you can keep up the pace for a while.

Zone 2 heart rate is great for improving cardiovascular health and the way your body metabolizes fat. It keeps your heart rate at 60 to 70 percent of its maximum. This allows for longer, sustained exercise without feeling super worn out after.

Zone 2 aerobic exercise helps boost endurance and supports heart health.

Heart Rate Zone 3

With a zone 3 heart rate, the intensity is high enough to challenge you, but it shouldn’t be so intense that you’re exhausted after a few minutes.

You should be able to sustain this level of intensity for about 20 minutes.

Since your body is working harder than in zones 1 and 2, it’ll also start tapping into extra energy sources — like carbohydrate and protein — as fuel. This helps you push through tougher workouts.

Heart Rate Zone 4

Now we’re entering the extra-challenging zones. That’s why zone 4 is best for shorter bursts of exercise.

The goal is to push yourself harder, but for less time. Zone 4 heart rate involves vigorous intensity, though it’s still not quite as intense as the next stage.

Heart Rate Zone 5

With a zone 5 heart rate, your heart rate will be at its peak because you’re working your absolute hardest. Since the intensity is so high, it’s not something you can sustain for long, making it perfect for interval training.

During those short bursts of max effort, your body mostly uses carbs and protein for fuel. This is where you really challenge yourself and push your limits.

Remember to listen to your body and allow for adequate rest and recovery between those intense intervals.

Let’s talk about how to figure out what your heart rate should be in each of the different heart rate zones.

To calculate your personal target heart rate zones, you’ll need to look at a few key data points:

• Maximum heart rate

• Resting heart rate

• Recovery heart rate

• Heart rate reserve

Let’s break down what each variable means and why it can be helpful.

Maximum Heart Rate

Sometimes called max HR, this is the highest number of beats per minute (BPM) your heart can safely handle during intense exercise.

Keep in mind your maximum heart rate can vary due to several factors, including altitude, genetics, body size, medical conditions, or medications you might be taking.

How to Figure Out Your Maximum Heart Rate

There are a few ways to determine your max heart rate:

• Lab stress test. This is the most accurate way to find your maximum heart rate. You wear a heart rate monitor while running on a treadmill or pedaling on a stationary bike at increasing levels of intensity until you can no longer keep going. The highest heart rate recorded during an intense push is your max HR.

• DIY test. If a lab test isn’t an option, you can recreate something similar at home or at the gym with a wearable heart rate monitor, like a wrist or chest strap. Just make sure to give it your all while also being safe.

• 220 test. You can get a good estimate of your maximum heart rate with a basic calculation: Subtract your age from 220. While this method is simple, it has its limitations. And it’s primarily based on data from men, so it might not be as accurate for everyone.

For instance, a 30-year-old guy who’s very fit might have a different max heart rate than a less-fit 20-year-old. Still, the 220 calculation can be a helpful starting point to figure out heart rate zones by age.

Resting Heart Rate

Resting heart rate is how many times your heart beats while you’re at rest — when you’re not being physically active. It’s a helpful indicator of your heart health.

To find your resting heart rate, you can manually check your pulse. Using a timer, count how many beats you feel in 60 seconds.

You might be curious if someone’s resting heart rate changes with age. The answer is yes. As you age, your heart rate will gradually slow down.

Generally, a resting heart rate ranges from 60 to 100 beats per minute. A lower resting heart rate often indicates better fitness levels, meaning as you become fitter, the number will decrease.

Recovery Heart Rate

Recovery heart rate is how quickly your heart rate and blood pressure return to their normal resting rates after a vigorous workout. While this metric isn’t always used to determine heart rate zones, it can be a helpful indicator of a person’s fitness level.

To figure out your recovery heart rate, look at the time it takes for your heart rate to drop back down to its resting rate after you finish exercising. This would happen during your cool-down period.

If you notice your recovery time getting shorter, that’s a good sign. It usually means your fitness is improving.

Just like with your resting heart rate, a quicker recovery points to better heart health. So, as you keep working out regularly and building your stamina, keep an eye on how fast your heart rate recovers — it’s an excellent reflection of your progress.

Heart Rate Reserve

Heart rate reserve is calculated by subtracting resting heart rate from maximum heart rate.

This number gives you valuable insight into how hard you can push yourself during exercise, especially anaerobic activities — those workouts that really get your heart pumping.

Some studies on men show that having a good heart rate reserve might help identify risk factors for death related to heart issues and type 2 diabetes.

Generally, a lower resting heart rate corresponds to a higher heart rate reserve, which suggests better overall fitness. In other words, the higher your reserve, the more fit you are.

Understanding your heart rate reserve can help you set effective workout targets and track your progress.

Once you have all the above components figured out, you can apply them to this formula to calculate how intensely you should be working out and what each zone will look like for you:

1. Maximum heart rate - resting heart rate = heart rate reserve

2. (Heart rate reserve x percent of intensity) + resting heart rate = training zone

The results can help you determine your target heart rate for each of the five heart rate training zones. It’s a little complicated, so consider using an online tool or calculator to crunch the numbers.

As far as tracking your heart rate while you’re working out, most people use wearable monitors, like a Fitbit or Apple Watch.

Different zones offer unique benefits, and what works best can vary from person to person.

Here are some general tips to help you figure out your own zone training approach.

Start Slow in Zone 1

The U.S. Department of Health & Human Services recommends starting with lower-intensity activities.

Gradually increasing the duration and frequency of your workouts helps prevent injuries and burnout. Warming up and stretching are also important.

Work Toward and Focus on Zones 2 and 3

Research suggests that regularly doing zone 2 and 3 workouts — often called sustainable endurance exercise — is particularly effective for supporting weight loss.

This type of training can also improve insulin sensitivity, lower the risk of heart disease, and enhance endurance. Plus, it tends to be easier on your body than high-intensity workouts and is great for burning fat and carbohydrates as fuel.

Splice in Some Zone 4

While zones 2 and 3 are ideal for endurance, zone 4 can be beneficial for building muscle — which can help with fat loss over time. High-intensity interval training (HIIT) fits into this zone.

HIIT alternates between high-energy bursts and short rest periods. It’s highly effective at improving body composition (BMI or body mass index), especially for those with overweight or obesity.

Bear in mind, high-intensity workouts are harder to sustain, so they shouldn’t make up the majority of your weekly physical activity.

Also, everyone’s body responds differently to exercise. What feels like zone 3 for one person might feel like zone 5 for someone else. Your personal target heart rate zones may change as you age, gain or lose weight, or improve your fitness level.

Incorporating heart rate zones into your fitness routine can be a game-changer for optimizing your workouts and supporting your weight loss journey.

Here’s a quick recap of what we’ve covered:

• Heart rate zones are based on the number of times your heart beats per minute. They can help you gauge exercise intensity.

• To calculate your target heart rate for each zone, you’ll need to know your maximum heart rate, resting heart rate, and heart rate reserve. These numbers can change over time, and it might be helpful to work with a medical provider or a fitness trainer to nail down the specifics.

• The five heart rate zones to remember are zone 1 (light activity), zone 2 (aerobic), zone 3 (more challenging), zone 4 (high-intensity), and zone 5 (peak effort).

• It’s best to focus on zones 2 and 3 for sustainable exercise that promotes fat loss and overall wellness. Consider zone 4 for high-intensity interval training to improve body composition, but balance it with lower-intensity workouts to prevent burnout.

• Everyone’s fitness journey is unique, so listen to your body and find an exercise program that feels right for you.

• Aiming for a holistic approach is also key. In other words, weight loss isn’t just about exercise. Eating nutritious foods, drinking enough water, and getting plenty of sleep are all crucial parts of the equation.

• If you have specific questions on how to use this information with your own fitness routine, like how to find zone 2 heart rate by age, you can use the 220 formula or consult a healthcare professional.

Remember, eating a balanced diet, staying hydrated, and making sure you’re well-rested are also critical pieces to the weight loss puzzle. And some people may need extra support, like weight loss medication, to achieve their goals.

If medication is something you’re considering, take our free assessment to find out which weight loss treatments could be a good fit for you.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.