Working out in the 'fat-burning zone,' also known as your
fat burning heart rate, is when your heart rate is between 70 and 80 percent of
your maximal heart rate.
The usual rule of thumb for losing
weight and staying fit is to increase the intensity of your workouts. But what
about the 'fat burning zone' notion, which suggests that you should instead
exercise at a lesser intensity? Is this concept accurate, and what is the
principle behind it?
Heart rate and fat loss: what's the connection?
Your muscles require glucose as a
source of energy. Glycogen (a carbohydrate-storing molecule) and fat, which
break down to generate glucose, carbon dioxide, and water, are the two major
sources of energy. To feed the muscles, oxygen is necessary to oxidise (break
down) glycogen or fat reserves into glucose.
Your body uses extra energy during
an exercise. As a result, your heart beats quicker and harder to deliver oxygen
to your muscle cells, allowing them to burn down more glycogen and fat for
fuel.
A gramme of carbohydrate contains 4
calories of energy, but a gramme of fat has 9 calories of energy. In comparison
to lipids, glycogen (carbohydrate) is a less dense kind of energy storage that
is easily broken down into glucose. As a result, during activity, glycogen is
your body's initial source of energy. Because high-intensity activities demand
a lot of energy rapidly, you use glycogen instead of fat as a source of energy.
When you run out of glycogen, your body switches to fat as a backup fuel.
The Fat-Burning Zone Myth: Is It True?
The fat-burning zone idea aims to
assist followers in losing weight by utilizing fat storage rather than glucose.
They claim that because the body does not require 'fast energy' from glycogen,
lower-intensity activities burn a bigger proportion of fat than
higher-intensity exercises. As a result, this idea encourages you to do longer,
lower-intensity cardio exercises to keep your heart rate in the 'fat-burning
zone.'
However, this is a common
misunderstanding. While the body does burn fat during low-intensity exercises,
the rate of fat burning remains modest, and you must exercise for longer to
burn the same amount of calories as you would at higher intensities.'
Although your body uses glycogen
stores first for 'fast energy,' a high-intensity workout depletes glycogen
stores quickly enough to require your body to dig into fat storage. This means
that high-intensity workouts burn more total calories – both glycogen and fat
calories – than low-intensity activities. In the end, the overall quantity of
calories you burn determines how much weight (and fat) you lose.
How to use your heart rate to estimate the intensity of
your workout
Your heart rate throughout the
exercise may be used to evaluate the intensity of your workout. The first step
is to figure out what your maximum heart rate is, which is the upper limit of
what your cardiovascular system can manage during exercise.
Subtract your age from 220 to get
your maximum heart rate. A 50-year-old, for example, will have a maximum heart
rate of 170. This suggests that this person's maximal heart rate is 170 beats
per minute on average.
Next, figure out what heart rate
zone you want to be in. This is the point at which your heart is being trained
and conditioned, but not to the point of being overworked. The following heart
rates are commonly suggested as goal heart rates:
50–70% of your maximal heart rate is
considered moderate workout intensity.
The intensity of vigorous exercise:
70–85 % of maximal heart rate
Remember not to hurry towards
attaining a high-intensity workout. Aim for the lower end of your desired heart
rate zone if you're just starting an exercise regimen.
Finally, you may use an activity
tracker or monitor your heart rate using the procedures below to see whether
you're in your goal heart rate zone:
Stop your workout for a few moments.
Place two fingers on your wrist,
closer to the thumb, and take your pulse for 15 seconds.
Calculate your heartbeats per
minute by multiplying this amount by four.
The four zones of training
Functioning out using a heart rate
monitor allows you to see what zones your body is working in and how different
levels of activity benefit your body. Your heart rate can forecast each of the
four primary training zones:
Warming up your cardio-respiratory
system, muscles, and joints prepares you to workout harder. You're working at
60–70% of your maximal heart rate in this position. It's a relaxed pace that
makes you feel like you could keep going for hours.
The so-called fat-burning zone is
just beyond the warm-up zone, and it's where you're working out at 70–80% of
your maximal heart rate. Although it is still a reasonable pace, you may sweat
and breathe more heavily than normal. Although you may burn fatter than
glycogen in this zone, the total amount of fat burned is significantly lower
than in the following phases.
The aerobic zone is still in the
comfortable zone. Your heart rate is between 81 and 93% of its maximum.
You'll be able to communicate, but only in brief bursts. The calories you
expend here are equally distributed between fat and glycogen reserves. You will
burn more calories overall, even if you do not burn more fat calories than
glycogen. (Plus, the aerobic zone gets your heart pumping hard, which is good
for your heart!)
Eventually, you will be in an anaerobic
area at 94–100% of your maximal heart rate. You can't speak because you're
panting. It's difficult to stay here for more than a minute since your glycogen
stores are being depleted quicker than they can be restored. Anaerobic
intervals broaden your fat and aerobic zones while consuming a large number of
calories. The afterburn (temporary increase in metabolism) kicks in at this
point. Excess post-exercise oxygen consumption (EPOC) occurs when your body
burns more calories after a high-intensity workout than after a low-intensity
session.
The amount your heart rate rises is
determined by the intensity of your activities. A running heart rate, for
example, should be between 50% and 85% of your maximal heart rate. Then,
depending on your goals for your run, you can change your pace. If your heart
rate falls below this level, you can pick up the pace to improve your workout
outcomes. Alternatively, if your heart rate hits its maximum, you should slow
down so that you can finish your run.
A high-intensity workout has several
advantages, including efficiently burning total calories both during and after
exercise and keeping your heart healthy. However, if you choose a low-intensity
workout, you will need to dedicate more time to burn the same number of
calories!
References:
The Truth about Exercise and Heart
Rate (n.d.).
http://www.webmd.com/fitness-exercise/features/the-truth-about-heart-rate-and-exercise#1
(accessed August 06, 2017).
P. Waehner, P. Waehner, P. Waehner (2017,
March 30). The Truth About Your Fat Burning Zone - How to Get Out of It and
Lose Weight
https://www.verywell.com/the-truth-about-the-fat-burning-zone-1231545 (accessed
August 06, 2017).
E. Quinn (2016, July 5). "The
Fat Burning Zone" Isn't What It Seems.
https://www.verywell.com/the-fat-burning-zone-3119977 (accessed August 06,
2017).
P. Waehner, P. Waehner, P. Waehner
(2017, May 18). 3 Ways to Increase Fat Burning Through Exercise
https://www.verywell.com/body-into-fat-burning-machine-1231548 (accessed August
06, 2017).
| Paul Rogers A board-certified
physician reviewed it. (February 2, 2017) How to Increase Fat Burning While
Exercising
https://www.verywell.com/how-to-burn-more-fat-secrets-of-exercise-physiology-3498340
(accessed August 06, 2017).
