While a lot has been made of that particular heart rate zone being the best to optimally burn fat, we are going to reveal why you should understand the whole picture when it comes to training heart rate zones and exercise production, and then before choosing to do one particular exercise intensity specifically to burn fat. While there is a certain heart rate training zone that will technically burn more fat than others, itas not necessarily a good idea to try to hit this HR zone in an effort to lose fat. It is only natural for individuals looking to lose weight to attempt exercise with intensity that keeps their heart rate in one of these zones. As a result, Fat Burning Zone Theory encourages longer, lower-intensity aerobic training sessions that keep the heart rate in the Fat Burning Zone.
When exercising with lower intensity and staying in one of the zones, you are burning fat more slowly, which is why you need to exercise longer in order to burn as many calories as you would through aerobic training. While it is true the body does burn fat in lower-intensity training, your rate of fat burning remains lower, and you need to exercise for a longer period of time to burn the same number of calories as you would in higher-intensity training. With walking, your body will be burning fat for energy, but you will be burning less calories than if you were running, which is higher-intensity exercise. The rate at which fat is burned starts to drop off with higher intensity, because your body needs the energy faster.
You are burning fat constantly to generate energy, but fat may burn more quickly as your activity intensifies. When you are exercising at a low to moderate intensity, the body uses fat, a slower-burning energy source, to power your muscles. If you raise your workout intensity too high, the body switches from burning fat to burning carbohydrates, so there is a middle ground if burning fat is your goal.
It is true that your body burns a higher percentage of fat at lower intensity levels compared to higher ones, but this does not mean slower, steady-state exercise is the most effective way to lose weight and keep it off. While the body burns a higher percentage of calories from fat when working out at lower intensities, higher-intensity workouts burn more total calories, which leads to more weight loss. High-intensity training has a number of benefits, burning overall calories effectively, both while exercising and afterwards, while keeping the heart healthy.
Generally speaking, your heart rate increases the more intense the workout, so you can theoretically estimate when your body is burning more fat by the number of strokes per minute that your heart is pumping. This is simply the number of times per minute that your heart is beating at a full stop, such as when you first wake up. This is the highest beats per minute (BPM) that your heart can hit in one really intense burst of activity – think, jogging up a hill. Sometimes called the fat-burning heart rate, your goal heart rate is essentially how many times per minute your heart needs to beat while exercising in order to make sure that you are burning enough calories, while also working hard enough to keep your ticker healthy.
Imagine your fat-burning heart rate falls somewhere between 135 and 174 beats per minute, so exercising somewhere in the middle of these numbers would burn maximum fat. Given that optimal fat burning heart rates are in the range of 67.6-87.1% of your maximal heart rate, you can define your Fat Burning Heart Rate Zone by multiplying your maximal heart rate by your smallest and largest percentiles.
Yes, lower-intensity exercises burn fat at the fat-burning heart rate zone, but higher-intensity exercises at the aerobic heart rate zone will also burn body fat, it is just not the main source. While exercising in that fat-burning zone will aid in fat loss, this may also help to explain why it takes longer for some people to lose fat with exercise.
All it really means is that, with lower intensities and over long periods of sustained exercise, of the calories burned, a greater percentage of them will be from fat. In low-intensity aerobic activity, such as walking, the fraction of fat used as energy might be higher, but you need to spend a lot more time burning that much calories than in vigorous 20-minute running. Any effort above a substantial amount of energy will burn more calories, which are obtained through the breakdown of carbohydrates and fat.
Since the technique was first used by researchers, studies have shown that when the intensity increases from about 40-70% of the persons VO2max–which is the maximum amount of oxygen the individual can use in a workout–there is a greater utilization rate of carbohydrates and fat. This is a broad range, ranging between resting heart rates around 70 bpm and about 160 bpm in medium-effort exercises (such as cycling at a steady pace, when holding a conversation becomes difficult), and it is here where a cross-over occurs from using fats to carbohydrates for energy. The graph illustrates the various heart ranges for your exercise program depending on your ultimate goal, whether that is increasing your aerobic endurance or burning fat.
Another thing to think about is how much fat we are actually burning while exercising (if we are talking grams per minute). We need to look at the whole picture of the output from the exercise over time, not just the initial burning of fat at a given time.
If you are sticking with lower- or moderate-intensity exercises in order to remain in a certain zone, then ultimately, you are burning less calories. Thatas why, if youare in your skill range for doing harder exercises for fat loss, youall be better off pushing yourself in a higher Zone than if you stayed within a lower Fat Burning Heart Rate Zone. According to a February 2011 review published in Clinical Nutrition, exercising around 70 percent of your max heart rate will motivate your body to burn more energy from fat, whereas exercising higher heart rates will motivate your body to burn more energy from carbohydrates.
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