Burning fat while exercising isn't just about putting in a lot of effort; it's also about being smart with your workout. One key strategy is to focus on your fat-burning heart rate zone. This article explains what the fat-burning zone is, how to find it, how to check your heart rate during workouts, and other important factors that affect fat loss.

Calculating Your Fat-Burning Zone

To find your fat-burning zone, you'll need two equations. The first one will calculate the lower limit, and the second will determine the upper limit of that zone.

Your fat-burning heart rate zone typically ranges between 50% and 70% of your maximum heart rate.

• Lower limit: Max heart rate × 0.50

• Upper limit: Max heart rate × 0.70

What Is a Fat Burning Zone?

The fat-burning zone is a heart rate range where your body mainly uses fat for energy instead of carbs. This usually happens when you exercise at a moderate intensity, which is about 60–70% of your maximum heart rate (MHR). At this level, your body leans more on fat for fuel.

While it might seem logical to work out harder to lose more fat, studies show that lower-intensity workouts in the fat-burning zone can actually help with long-term fat loss. This is especially true for beginners or those who are concentrating on building endurance.

Determining Your Maximum Heart Rate

Maximum heart rate is the highest number of times your heart can beat in a minute, usually during exercise or stress. You'll need this number to figure out your fat-burning zone, as shown in the equations above.

There is some discussion among experts on the best way to figure out maximum heart rate. One common method is the Fox formula. While it can be helpful, it doesn't take into account personal differences, especially factors like gender and fitness level that can affect your maximum heart rate.

Still, it is the recommended method of the American Heart Association. The Fox formula is calculated as follows:

Maximum Heart Rate (MHR) = 220 − your age

For example, if you’re 40 years old:

MHR = 220 − 40 = 180 bpm

Your fat-burning zone would be:

60% of MHR = 180 × 0.60 = 108 bpm 70% of MHR = 180 × 0.70 = 126 bpm

So, a 40-year-old would aim to keep their heart rate between 108 and 126 bpm to stay in the fat-burning zone.

Note: More accurate methods, such as the Karvonen formula or lab testing, take into account your resting heart rate and personal fitness levels. However, the 220-age method is commonly used for general guidance.

Fat-Burning Zones by Age

This chart shows fat-burning heart rate zones based on age. If you don't want to do the detailed calculations, you can use this chart to find a general target heart rate for burning fat.

Monitoring Heart Rate During Workouts

To get the most out of fat-burning workouts, monitoring your heart rate is crucial.

Tools to Use:

Heart Rate Monitors (HRM): Chest straps (like the Coospo Heart Rate Monitor) offer precise readings in real time.

Smartwatches & Fitness Trackers: Convenient, though slightly less accurate for intense workouts.

Manually (Pulse Check): Find your pulse on your wrist or neck and count the beats for 15 seconds × 4.

✅ The Coospo Heart Rate Monitor is a reliable and affordable tool to track your heart rate across zones. When connected to a fitness app or cycling computer, it helps you stay within your desired intensity range, improving workout efficiency.

Exercises for Fat-Burning

Energy sources for exercise depend on how intense the activity is. When the activity is less intense, the body gets more of its energy from fat.

Some examples of lower-intensity exercise include:

Walking

Cycling

Swimming

If you’re not sure whether an activity qualifies as low-intensity, you can do the talk test. Most people can talk and sing during low-intensity activity. If you can talk but you can’t sing, then the activity can be considered moderate intensity.

During intense exercise, most people can't speak a whole sentence without pausing to catch their breath.

If you want to burn fat, look for a low-intensity exercise that you enjoy and can do regularly, most days of the week.

It's important to understand that exercising at a lower intensity burns fewer calories each minute compared to higher intensity workouts. If you don’t have much time to exercise, a more intense workout might help you burn more calories, as long as you are healthy and able to handle that level of effort.

Other Considerations When Trying to Lose Weight

Exercising in the fat-burning zone can help use up fat, but losing weight really depends on burning more calories than you take in. Here are some other important things to consider:

Caloric Intake

To lose weight, you need to burn more calories than you eat. Even if you're exercising in the fat-burning zone, eating too much can undo your progress.

Insoluble Fiber

Insoluble fiber helps with digestion and makes you feel full. Foods such as whole grains, leafy greens, and seeds can keep you satisfied longer, which may help prevent overeating.

A 2015 study in Annals of Internal Medicine showed that simply increasing fiber intake led to weight loss, even without strict dietary changes.

Health Conditions

Conditions like hypothyroidism, PCOS, or insulin resistance can make it harder to lose fat. If you’re working out regularly but not seeing changes, it’s a good idea to speak with a healthcare provider to check for any underlying issues.

Resting Metabolic Rate (RMR)

Your RMR (resting metabolic rate) is the number of calories your body uses when you're not doing anything. It can be influenced by your age, muscle mass, and genes. By building more lean muscle through weight training, you can boost your RMR, which helps you burn more calories all day long.