Exercise heart rate has been touted for decades as an effective means for determining whether you’re burning fat during exercise, and pundits for tracking heart rate zones have even marketed it as an effective way to lose body fat.
However, the truth about the fat-burning heart rate zone is far different from what you've been led to believe.
Here's everything you need to know about the heart rate to burn fat.
What is the Fat Burning Heart Rate Zone?
If you have ever hopped on a piece of cardio equipment or used a fitness tracker, you're well acquainted with the fat-burning heart rate zone.
The fat-burning heart rate zone is the heart rate zone in which your body uses more fat for generated energy (ATP) than carbohydrates.
Your fat-burning heart rate is about 70% of your maximum heart rate.
Your maximum heart rate is the maximum number of times your heart should beat during exercise.
Fat burning heart rate zone isn't the only heart rate zone that's measured, though. Other heart rate zones are:
- Resting (minimum) heart rate
- Moderate heart rate (50-70% of maximum heart rate)
- Target heart rate
- Maximum heart rate
Typically, moderate and target heart rate zones are defined as percentages of your maximum heart rate and are closely linked with your aerobic and anaerobic thresholds.
To calculate your maximum heart rate, subtract your age from 220.
For example, a 25-year-old’s maximum heart rate is 220 minus 25 — or 195 beats per minute.
How the Fat Burning Zone Works
When you train in your fat-burning heart rate zone, your body uses more body fat for energy than carbohydrates (either muscle glycogen or blood sugar). The theory is that burning more fat from fuel during exercise than doing the same exercise at a higher intensity leads to more significant fat loss.
To put things in perspective, fat accounts for up to 85% of calories burned during rest. That percentage decreases to ~70% when walking at a leisurely pace. If you transition to a moderate-effort run ("jogging"), it's roughly a 50/50 split between fat and carbohydrate supplying energy for exercise. As intensity continues to ramp up, so does the percentage of carbohydrates burned for ATP production.
However, even during high-intensity exercise, a percentage of energy is still derived from body fat.
So, what does all this mean in terms of body fat loss?
Link Between Heart Rate and Fat Loss
While many gurus and influencers would have you believe that training in the fat-burning heart rate zone is "optimal" for losing body fat, the truth is that the heart rate zone doesn't matter.
Burning calories matters, which can be accomplished through a mixture of dietary modification (i.e., calorie restriction) and exercise.
The human body is incredibly adept at modifying and adapting to whatever you throw.
For instance, let's say that you have the most optimal work that keeps you training in your fat-burning heart rate zone for the entire duration of your workout. Well, guess what?
During the other parts of the day, your body will burn a more significant percentage of carbohydrates for energy, even during rest!
Something else to consider is that you burn more calories per minute when exercising at a higher intensity compared to performing the same exercise at a lower intensity.
This becomes especially important for those individuals with limited time to train.
If you only have 20-30 minutes to exercise during the day and want to maximize the amount of calorie burning that takes place, then you better get after it with some intense training.
Sure, you'll burn more carbohydrates for energy than body fat. Still, the net result is an overall more significant energy burn than if you trained at a lower intensity for the same duration.
Remember, calories matter at the end of the day, not how many calories were burned from a specific macronutrient.
If you consistently maintain a calorie deficit, even while eating a high-carb diet and doing intense exercise (e.g., resistance training, circuit training, HIIT, sprinting, etc.), you'll still lose body fat.
Is the Fat Burning Heart Rate Zone Useless?
Not necessarily.
If you're a data junkie who likes to track and log every metric possible of your human existence, then sure, you can track how much of your day you spend in the fat-burning zone. However, for the average individual looking to lose body fat, build muscle, and live a healthy, pain-free lifestyle, tracking your fat-burning heart rate zone is not important or necessary.
If you do want to track something, then several other metrics would be more valuable, such as:
- Daily protein
- Daily calorie intake
- Daily steps
- Weights/sets/reps in resistance-training workouts
- Active minutes
- Time in various stages of sleep (REM, light sleep, deep sleep, etc.)
- Resting heart rate
- Heart rate variability
What Type of Exercise Should I Do to Lose Body Fat?
Want to know another “dirty” secret that most trainers, gurus, and influencers won’t tell you?
You don’t actually “have” to exercise to lose weight.
Remember, a calorie deficit is required for weight loss. That can be accomplished by living an active lifestyle (general movement during the day) and reducing calorie intake.
The reason that exercise is recommended along with calorie restriction is that it is most “optimal.”
Exercise increases the amount of calories you burn during the day (total daily energy expenditure -- TDEE), which means you can consume more calories compared to not exercising, yet still, be in a deficit (and thus lose weight).
Regular exercise also boosts metabolism, improves mood, supports cardiovascular health, bolsters immune function, supports better sleep, and promotes insulin sensitivity.
Certain forms of exercise (resistance training, HIIT, etc.) also help build muscle and strength and combat muscle breakdown, which can happen whenever you diet for fat loss.
As for the “best” type of exercise to lose fat, there are none. Choose the types of exercise that you enjoy and motivate you to show up every week and put in the work.
For some, that could mean just regular walking during the day. For others, it could be a combination of resistance training and traditional "cardio."
And still, for others, it could be a mix of workouts, including high-intensity interval training, walking, fat-burning heart rate workouts, and resistance training.
Scale your workout program to your lifestyle, preferences, and goals, and don't worry about whether you're in the fat-burning heart rate zone or not.
Supplements to Help Support Fat Loss
Any time the subject of fat loss comes up, invariably, there will be questions about whether or not supplements can help.
The truth is that supplements can help support fat loss. The issue is that most individuals expect the supplements to do all the work, and they can continue to live their life as is (which usually means eating whatever they want and exercising sporadically).
The utility and efficacy of supplements are greatly enhanced when paired with diet and exercise.
If you've already got the diet and exercise components of your weight loss plan in place and looking to support fat loss further, here are some options:
Steel Core®
Formulated specifically for those looking to tone and define their midsection (which is most of the gym-going population), Steel Core® is our stimulant-free fat-burning supplement formulated to mobilize fat, improve metabolism, and increase calorie burning.
Shredded Steel®
For those looking to turbocharge your fat loss journey, check out our premium thermogenic fat-burning supplement -- Shredded Steel®.
Shredded Steel® delivers a precise combination of research-backed ingredients to encourage fat burning, increase energy levels, enhance mental focus and clarity, and suppress appetite.
Steel Sweat®
Who doesn’t love to break a sweat during a hard workout?
While a tough training session is all needed to get the sweat rolling, using a thermogenic pre-workout powder can open the flood gates.
Steel Sweat® is our delicious-tasting thermogenic pre-workout powder ideally suited for those cardio sessions where you want to burn extra body fat and those that want a low stim pre-workout supplement for resistance training.
