Every health and weight loss advice stresses importance of regular exercise. But why heart rate has been linked with losing weight? This is for the reason that when you exercise your heart rate increases. Therefore, fitness gurus advise exercising in the fat burning heart rate zone for maximum fat loss.
Fat loss and weight loss
Apparently, both look the same. However, it is possible to lose weight without fat loss too. For example, you might lose weight by creating a calorie deficit. You will lose weight but all of that might not be from fat loss.
This is especially true when you are doing high intensity exercise because most of your burned calories at high intensity physical activity are from carbs and not fats. We will see below that your heart rate while exercising determines how much fat you will be losing during it.
Before we give you your exact fat burning heart rate, there are few terms related to heart rate that you need to understand.
Resting heart rate
This is the average resting heart rate at which your heart beats per minute. It is easy to measure your resting heart rate by counting your pulse for 15 seconds and then multiplying the count by 4. For example, if your pulse count for 15 seconds is 18, then your heart rate at rest would be 18×4 = 72.
It is important to note that you should measure your average resting heart rate when you have not exerted for about half an hour, while sitting peacefully and without taking any coffee or tea in half hour before taking this measurement.
It will be a good news if your resting heart rate will be within the normal heart rate range which is between 60 and 100 beats per minute. However, professional athletes and people with excellent fitness level may have much lower resting heart rates in the 40s. Generally, a lower heart rate at rest indicates better fitness and a healthier heart.
Maximum heart rate
Average maximum heart rate changes with age. But it has a simple formula. All you need to do to find your maximum heart rate is to subtract your age from 220. For example, if your age is 35 you can get your maximum heart rate of 185 by subtracting 35 from 220.
This is the maximum safe heart rate for your body at your age. From here we will calculate the target heart rate for fat loss.
Target heart rate
Once you have your maximum heart rate with you, next you can find your target heart rate (a range in which your fat burning heart rate zone also lies). The target heart rate zone is between 50 and 85 percent of your maximum heart rate. This is the safely elevated heart rate range at which your body gets benefits of exercise. Anything lower than that is not that beneficial and anything higher than that means you are pushing yourself too hard.
This target heart rate can be further sub classified into moderate intensity exercise heart rate zone and vigorous intensity exercise heart rate. For moderate intensity physical activity, the target heart rate zone is between 50 and 70 percent of maximum heart rate and for vigorous physical activity it is between 70 and 85 percent.
So taking forward our above example of a 35-year old whose average maximum heart rate we calculated as 185, we can find that her target heart rate is between 93 and 157 beats per minute.
Optimum fat burning heart rate zone
As we explained above, the target heart rate zones for moderate and vigorous activity are different. But interestingly when you start moderate activity your body burns most of its calories from fat. As you increase intensity of your physical activity, your body starts to get most of its energy from carbs.
So, it might be tempting to say assume that we should only be doing moderate intensity exercise because that’s where the fat burning heart rate zone is. However, high intensity heart rate zone doubles the calories burned in the same time. Therefore, it depends on the time at your disposal as well as your fitness level. Because more calories out of your body would mean greater weight loss.
Our body gets almost 85 percent of its energy from fat in rest. The energy mix changes to about 70 percent from fat while walking. This changes significantly when running because at this stage the body’s energy needs are met half by fat and half by glucose.
But if your main target is reducing body fat, then probably moderate intensity exercise like brisk walking is your best bet. But if your target is not only fat loss but also quick weight loss then a vigorous intensity exercise like running can produce both results in shorter time.
Heart health and heart rate
The target heart rate zone is not only important for fat loss, its main benefit is for improving cardiovascular health. Exercise increases heart rate which strengthens heart, which is a muscle like other body muscles.
From this perspective, fat burning heart rate zone at moderate physical activity is sufficient for improving cardiovascular health. In fact, US Dietary Guidelines recommend minimum 150 minutes of moderate physical activity per week. This recommendation is reduced by half if you undertake strenuous physical exercise like running.
Below is a chart of target heart rate according to your age.
|Age||Target Heart Rate (beats per minute)|