The Correlation Between Heart Rate & Fat Burn During Exercise

fasting for weight loss

Training in an optimal heart rate zone will allow you to burn more fat while spending less time in the gym. 

Burning fat and weight loss are integral components of bodybuilding. In the cutting phase, you carefully manage your diet and employ training techniques to shed fat while preserving muscle mass (1). Besides nutrition, the significance of your heart rate (HR) during exercise cannot be overstated for it’s fat-burning ability. In this post, we look at how your heart rate during exercise affects fat burn and dive into the best heart rate for weight loss.

Have you ever wondered about the increase in how fast your heart beats when you exercise? For most people, this is a sign of how tired they are. However, your heartbeat is much more than a fatigue barometer and can indicate how many calories you burn during physical activity. An optimal heart range while training can help you improve your fitness level and physique. 

Heart Rate & Exercise 

best heart rate for weight loss

Your heart rate refers to the number of times your heart beats in a minute. This rate can show when you’re in the fat-burning zone when training. On this premise, most athletes use high-intensity training to lose weight since that’s when their heart rate is the most elevated (2)

Best Heart Rate for Weight Loss 

Your heart rate is also a fact-based way to measure exercise intensity. Everyone has a maximum heart rate, calculated by subtracting your age from 220. For moderate-intensity activities, the goal is often to hit 50-70% of your maximum heart rate. High-intensity exercises could hit as high as 70-85% of your maximum rate, and your fat-burning zone falls in this range. 

However, note that being in the fat-burning zone doesn’t guarantee you’ll lose weight. Losing weight involves multiple factors, such as diet and metabolism. But training in the proper heart range will surely help, especially if you’ve been stuck at a plateau. Additionally, it’ll help you burn fat and calories faster, meaning you can spend less time training if you’re in the optimal zone.  

Fat Burning Heart Rate Calculator 

To fully understand the heart rate that leads to fat burn, it’s essential to look at the other heart rate classes when exercising. 

Very Light Heart Rate Training

You typically start with the very light class, where you do low-intensity training. This raises your heart rate just above your resting heart rate. Very light heart rate training hits 50-60% of your maximum heart rate.

Light Heart Rate Training

Light heart rate training raises your heart rate to around 60-70% of your maximum. This is the range where traditional aerobic activities take you. Training at this point uses energy stored as glycogen in your muscles or unused calories that could have ended up stored as fat.

Moderate Heart Rate Training

Moderate heart rate training hits about 70-80% of your maximum heart rate. This is one of the most optimal fat-burning ranges (3). During this time, your workout stays where you can sustain them without gassing out. As a result, you can maximize your capacity and keep that high heart rate steady for better fat-burning results.

Heavy Heart Rate Training

You hit around 80-90% of your maximum heart rate during heavy heart rate training. While you burn fat at this point, you can only sustain your efforts for a maximum of 10 minutes at once. However, this isn’t the highest, although it’s still considered high-intensity training.

Maximum Heart Rate Training

At the maximum heart rate training, you hit a solid 90-100% of your maximum heart rate. At this point, your body will burn a considerable amount of calories in just a short time. However, this training level is hard on your endurance, and most athletes cannot sustain it for over 15 seconds.

How to Measure Your Heart Rate

fat burning heart rate calculator

Exercising at the optimal level of intensity can help you burn fat quickly and maximize your gains. So, measuring your heart rate and determining when you hit that level is essential if you’re trying to burn fat. There are two primary ways to measure your heart rate:

Checking Your Pulse Manually

While exercising, you can use the following method to check your heart rate and determine which zone you are in:

  1. Pause briefly and take your pulse for about 15 seconds. You can check using either your neck or your wrist.
  2. For your neck, place your index and third finger on your neck at the side of your windpipe.
  3. If checking at your wrist, put two fingers on your radial artery, located between the bone and tendon on the thumb side of your wrist. 
  4. Time yourself, and at the end of 15 seconds, multiply whatever your score is to know your heartbeat per minute. 
  5. Compare this to the answer of 0.7 x your maximum heart rate to know if you’re in the 70% range.  

Using Fitness Trackers

There are multiple versions of fitness trackers to use for your heart rate. There are heart rate monitors that you can wear during your workouts to check your range. Machines like ellipticals or treadmills come with a pulse tracker, which also works here. In addition, multiple smartphone apps can measure your heart rate using camera technology. 

Wrapping Up

Your heart rate during exercise is vital to weight loss. An optimal fat-burning zone is when you hit a heart rate of around 70-80% of your maximum heart rate. Most athletes can sustain their routine for longer than 10 minutes at this level and keep burning fat. You can still lose weight with a lower heart rate, but you’ll need to workout longer to burn the same amount of calories. On the contrary, if your HR is too high, you’ll spend too little time exercising needed to burn fat since you’ll tire out quickly. 

You can lose weight in traditional aerobic, moderate-intensity, and high-intensity training. You’ll lose weight if you burn more calories than you consume. High-intensity training, however, enables you to do this in significantly less time. 

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  1. Lenzi, J. L., Teixeira, E. L., de Jesus, G., Schoenfeld, B. J., & de Salles Painelli, V. (2021). Dietary Strategies of Modern Bodybuilders During Different Phases of the Competitive Cycle. Journal of strength and conditioning research, 35(9), 2546–2551.
  2. Maillard, F., Pereira, B., & Boisseau, N. (2018). Effect of High-Intensity Interval Training on Total, Abdominal and Visceral Fat Mass: A Meta-Analysis. Sports medicine (Auckland, N.Z.), 48(2), 269–288. 
  3. Carey D. G. (2009). Quantifying differences in the “fat burning” zone and the aerobic zone: implications for training. Journal of strength and conditioning research, 23(7), 2090–2095.
Terry Ramos
As a personal trainer and writer, Terry loves changing lives through coaching and the written word. Terry has a B.S. in Kinesiology and is an ACSM Certified Personal Trainer and ISSA Certified Strength and Conditioning Specialist. He enjoys playing music, reading, and watching films when he's not writing or training.