Your intention when you lose weight is to drop fat, not lean muscle tissue. Certain types of exercise expend more energy than other types, improving your capacity for burning more calories and therefore more fat.
You can't really directly measure the number of fat grams burned through cardio; cardio burns calories, which helps deplete your fat stores. And, exactly how many calories you burn in a workout depends on the intensity, your size, your body composition, your metabolism and your genetics.
The number of fat grams burned during cardio depends on several factors, including your weight, metabolism and the intensity of your exercise.
Fat vs. Calories
The intensity of cardiovascular exercise determines how many calories you burn from fat and how many you burn from carbohydrates. In general, a lower intensity exercise tends to burn a greater percentage of fat calories, but fewer total calories overall. For weight loss, focus on total calories burned rather than a special "fat-burning" zone.
Exercise Intensity and Fat
According to a July 2016 article published by independent researcher Dr. Philip Maffetone, low-intensity cardio workout that raises your heart rate to 50 to 70 percent of your maximum heart rate utilizes more fat for energy than carbohydrates. The higher the intensity of your workout, the less fat you will burn.
As you get closer to your maximum heart rate, the percentage of fat burned progressively decreases. However, if you exercise for longer periods of time, you will burn more fat. For example, if you burn 100 calories in a workout at a low intensity, 60 calories came from fat. But, if you burn 250 calories in a workout at a higher intensity, up to 75 calories may have come from fat — even though it burned a lower percentage of fat calories.
Read more: The Burn Fat Faster Workout
What It All Means
If you're truly concerned with determining fat grams burned, consider the following equations. To burn 1 gram of fat, you need to burn 9 calories from fat. Since moderate-intensity exercise such as moderate bicycling, burns roughly 210 to 311 calories in 30 minutes, you can estimate that 50 to 60 percent of those calories comes from fat.
That translates to 105 to 155 calories burned from fat. At nine calories per gram, you burn approximately 11.7 to 17.2 g of fat in 30 minutes, or two times that amount in 60 minutes. This is an extremely rough estimation, however.
Although you may have heard a great deal about the fat-burning zone — then supposed level of exercise intensity that burns the most fat — the number of fat grams you burn or the percentage of fat you burn during exercise is not the key to losing weight or fat with exercise.
The key is to burn more calories than you take in. As long as you're not severely limiting your caloric intake below 1,200 calories per day for women or below 1,800 for men, and causing your metabolism to rebel and slow down, you'll lose fat if you create a calorie deficit. Watch what you eat, particularly the number of total calories and the overall quality of your food and beverage choices.
Read more: The Ultimate Guide to Fat Loss
- Centers for Disease Control and Prevention: Physical Activity for a Healthy Weight
- Centers for Disease Control and Prevention: "General Physical Activities Defined by Level of Intensity"
- Harvard Health Publishing: "Calories burned in 30 minutes for people of three different weights"
- Dr. Philip Maffetone: "MAF Heart Rate: How it can help improve health and sports performance"