How to Use Target Heart Rate Training Zones

Whether you're doing cardio exercise for health, fitness, or weight loss, it's important to work at a certain level of intensity. Your target heart rate is a more exact method of determining your exercise intensity rather than using your perceived exertion. Learn how different target heart rate zones can be used in your workouts to help you reach your goals.

Find Your Target Heart Rate

Your target heart rate numbers will depend on your age and fitness level. There are a few ways to determine these. You can use the Karvonen formula or a target heart rate chart.

Even more conveniently, heart rate detection is now featured in many activity monitors as well as chest strap heart rate monitors. These devices will ask you for your age, monitor your resting heart rate, and determine your heart rate zones for you.

During exercise, these devices will often indicate which heart rate zone you are in so you can increase or decrease your exertion. In comparing Whoop vs. Fitbit fitness trackers, for example, Fitbit is able to track how long you spent in your optimal heart rate zones. As well, some treadmills, stationary cycles, and elliptical machines will have handgrip heart rate detectors that allow you to monitor your heart rate zones.

The target heart rate zones for aerobic exercise range from 50 to 100% of your maximum heart rate. You will see a confusion of numbers when you check different references. For consistency, the heart rate zones referenced by the U.S. Centers for Disease Control and Prevention and the American Heart Association will be explained.

Low Intensity: 40 to 50% Max Heart Rate

The low-intensity heart rate zone keeps you at a comfortable heart rate and is a good choice for beginners or as a warmup. You should always start an exercise session with a couple of minutes in the low-intensity zone to get your blood circulation going. Beginners may start with low-intensity cardio to build exercise tolerance and get used to walking, cycling, or using cardio equipment.

At low intensity, you are getting the benefits of being active rather than sedentary. Sitting for long periods can raise health risks. The drawback of staying in this zone is that you are not getting the extra benefits of moderate-to-vigorous intensity exercise in reducing health risks or achieving the minimum amount of exercise recommended each day.

Examples of a low-intensity cardio workout are to take a walk at a comfortable, easy pace or use a stationary cycle with little tension in pedaling.

Moderate Intensity: 50 to 70% Max Heart Rate

Experts often recommend working at a moderate intensity to build fitness and lose weight. Cardio workouts in the moderate-intensity exercise zone improve your body's ability to transport oxygen and condition your heart. You'll burn more calories and fat in this zone, as well.

To reduce your health risks, you should get 150 minutes of moderate-intensity cardio per week, with workouts of at least 10 minutes in this zone. The workouts should be spread throughout the week. Examples of moderate-intensity cardio workouts include brisk walking, easy jogging, bicycling under 10 mph, and light weight lifting.

High Intensity: 70 to 85% Max Heart Rate

Working in the high-intensity heart rate zone takes you out of your comfort zone and allows you to burn more calories. You build aerobic fitness in this zone, improving your VO2 max (your maximum rate of oxygen use).

Consistent high-intensity workouts can raise your anaerobic threshold (or lactate threshold), which is the point at which your body must use less-efficient pathways to generate energy for your muscles.To reach the minimum recommended amount of exercise each week you need 75 minutes in bouts of at least 10 minutes in this zone at a time, preferably spread throughout the week.

A combination of high-intensity and moderate-intensity exercise will also meet the guidelines. Examples of high-intensity cardio workouts include running, lap swimming, cycling faster than 10 mph, and high-intensity aerobic intervals workouts.

Maximum Effort: 85 to 100% of Max Heart Rate

Working at this level means you're working as hard as you can, as in all-out sprints or very high-intensity interval training. Most people can only sustain this level of effort for a short period of time, making this the toughest zone and more appropriate for advanced exercisers. A sprint interval workout is an example of training at maximum effort with rests in between work intervals.

A drawback of exercising at maximum intensity is that you are above the anaerobic threshold and producing lactic acid. This by-product leads to "feeling the burn" in your muscles and post-exercise muscle soreness.

A Word From Verywell

Enjoying workouts in each of the heart rate zones will help you build physical fitness in different ways. It's good to mix it up for variety rather than thinking there is one best kind of workout. As well, health authorities such as the CDC note that getting more exercise than the minimum recommendations is better for maintaining weight loss and reducing health risks.