Knowing the best heart rate to burn fat is crucial when you do cardio to get rid of some extra weight. Usually we tend to imagine that the more cardio, the more fat we burn. But is it always true?
The answer may surprise you as it surprised me when I found out.
I think it is normal to think that, if some cardio exercise burns some fat, much more cardio will burn much more fat.
It is not true, or at least it is true only in part.
More cardio clearly burns more fat than less cardio but only when you exercises at the same heart rate.
Pushing your body to exercise at a very high heart rate makes you burn more calories, this is true, but not so many from fat.
For example, exercising at 90% of your maximum heart rate will burn only around 15% of calories from fat. Don't get me wrong, it doesn't mean that you shouldn't train at that intensity because it's still a great workout for your heart which is the most important "muscle" of your body.
I think I did lots of cardio at that intensity thinking that it was the perfect heart rate to burn fat, but I was wrong. I don't regret doing it, but for sure I wasn't burning as much fat as I thought.
One day at the gym I was warming up on an elliptical and I started looking at the charts on the display: age|maximum heart rate|65%|80%|90%. All these columns in a nice table that I had never paid attention to before.
While I was panting on that machine I killed some time by trying to read the legend and understand those numbers.
The column 65% was colored red: fat burn.
Translated, it means that the best heart rate to burn fat is 65% of your maximum heart rate.
At that rate most of 50% of the calories that you burn come from fat, which is great. It is the highest percentage of fat burn that you can reach during cardio exercises.
I have to admit that I was very surprised. I thought that the faster I was running the more fat I was burning.
Training at higher heart rates burns more calories, there's no doubt about it, but a smaller percentage comes from fat burn.
For example at 80% of your maximum heart rate 50% of the calories you burn come from fat. With a very high heart rate around 90% you have only 15% of fat burn.
I hope that now you have a better understanding of all those cardio programs that you can choose on the machines. They are specifically designed for different purposes so make sure you don't choose randomly but based on what your goal is between fat burn, endurance, performance training etc.
To summarize a little bit let's have a clear view of different heart rate trainings.
Fat Burning Zone
Heart Rate: 60-70% of maximum heart rate.
It's the best heart rate to burn fat because it allows you to work out for long periods of time.
The percentage of calories burned that comes from fat is up to 85%.
Heart Rate: 70-80% of maximum heart rate.
This is the heart rate that you should train at to improve your cardiovascular and respiratory system. At this rate you can increase size and strength of your heart.
The percentage of calories burned that comes from fat is around 50%.
High Intensity Zone
Heart Rate: 80-90% of maximum heart rate.
At this rate you can raise your metabolism and burn more fat as a consequence.
Although during exercise this is a rate that burns more calories than the previous ones, only 15% are from fat.
At this rate your body burns all the carbs available.
Maximum Effort Zone
Heart Rate: 90-100% of maximum heart rate.
First of all it's dangerous to train at your maximum heart rate. You should consult a physician before attempting this type of training.
When you exercise at your maximum heart rate you burn the maximum amount of calories, but even a smaller part are from fat. Consider that at this intensity you can train only for very short periods of time
There is a very simple formula to calculate what your maximum heart rate should be, actually there is one for men and one for women.
Men's Max Heart Rate = 220 - age
Women's Max Heart Rate = 226 - age
That means that if you are 35 years old, your maximum heart rate is 185 (man) or 191 (woman).
If you want to monitor your heart rate while you exercise, well, you need a heart rate monitor. I personally like this ones, but there are many other types: