What is the Best Heart Rate for Burning Fat? This question can also be put in another way – is there really a fat burning zone? The answer to this is no. The idea of a ‘fat burning zone is a myth. It is a myth that is circulating amongst the fitness community, and the sad thing is, that many people tend to blindly believe in its existence.
In order to better understand the hollowness of the fat burning zone theory, one must first realize that at a given time, amid some physical activity, the energy supply to the body actually comes from the burning of a mix of fat and carbohydrates, the exact proportion of which in fact may vary with the intensity of the workout. If you look deeper into this final point, there is a hidden piece of fact embedded in it. Which is that, at lower or moderate levels of physical activities, more energy is produced by burning fat than carbohydrates and proteins (mind you, it is also a source for energy to the body). Many have mistook this or have exploited this info and created the fat burning zone theory, which actually is nothing but a block of letters taken out of a sentence that actually conveys the full meaning or sense about the given topic. Actually, what contributes to weight loss is not the amount of fat burnt over a period of time, but the total amount of calories expended as a result of the workout. For a person who is looking to shed a few calories from his/her waist, the focus must be upon burning as much calories as possible in a workout session and not the amount of fat converted into energy, for it is the total calories burnt that matters in the end. And to achieve that goal, moderately intense exercise is always better than low intensity exercises. That again shuts out the fat burning zone theory.
That brings us to the core topic – the standard to measure the intensity of a workout – the heart rate. The ideal heart rate or the intensity zone for an ideal workout session can be determined from the famous Karvonen equation.
The Karvonen equation involves two variables, Max HR (maximum heart rate) and Rest HR (rest heart rate). Max HR is obtained by subtracting one’s age from the constant 220. Rest HR, on the other hand, indicates the pulse rate for a minute, the measurement being taken as the first thing done in the morning with the person in a seated position, at rest. Now, the lower and upper end of the target heart rates are calculated using the formulas, (Max HR – Rest HR) x .50 + Rest HR for lower end and (Max HR – Rest HR) x .80 + Rest HR for upper end respectively.
So, as an example, consider a 30 year old person whose Rest HR is 70. So, his/her Max HR can be calculated as 190 (220-30). Using the Karvonen equation, his/her lower end of range can be calculated as (190-70) x .50 + 70 = 130, and the higher end of range as (190-70) x .80 + 70, which is equal to 166. That is, the target heart beat range or the aerobic zone is between 130 and 166 heartbeats per minute and for maximum calorie burning benefits, the person must ideally maintain his/her heart rates within these limits. It will be difficult to maintain these levels for a longer period of time, in one stretch, and hence it is advisable that one may take breaks in between or revert to a lighter sessions before again stepping on the pedal.
For beginners, it will be better to start near the lower end of your range and gradually increase it to near the maximum range. Taking too much strain in one go is injurious to one’s overall health.