Are Exercising to Burn Fat and Exercising to Burn Calories the
Same Thing? by Ainsley Laing
The methods that work for each individual vary depending on the individual's weight,
cardiovascular fitness level, activity level, metabolism, muscle development, size and
For all of us, though, if we eat more than our body requires – we either store it as fat
or have to "burn it off".
The body at rest uses energy (calories) to power the organs, brain, cardiovascular
system, immune system and skeletal muscle. In other words, all of the cells of the
body require energy. The rate in which the body uses energy to function is known as
the basal metabolic rate. There are two other areas of calorie requirements, one
known as the thermic effect of eating (energy required to digest food) and the
thermic effect of exercise.
So how does the body convert energy for use during exercise? There are 3 principle
metabolic pathways, which are the ways in which the body produces Adenosine
Triphosphate (ATP). I promise not to go too technical here and risk boring you…
1. The ATP-PCr System
This is used during the first few seconds of exercise. Creatine phosphate (PCr) in the
blood is used to produce ATP which powers the cells.
2. The Glycolytic System
Glycolysis means the breakdown of glucose. The body uses this system for the first
few minutes of exercise. If the exercise is very intense (say sprinting), glucose in the
blood is used without oxygen and the by product of this will be lactic acid. After a
while, the lactic acid accumulates (the burning sensation in the muscle) and leads to
muscle failure. This is known as anaerobic or fast glycolysis. If the exercise is less
intense (jogging), glucose in the blood is used with oxygen to produce ATP and the by
product will be pyruvate which then is used by the oxidative system below. This is
known as aerobic or slow glycolysis.
3. The Oxidative System
This system is has 4 parts which I definitely won't go into except to give you the
names: slow glycolysis (discussed above), the Krebs Cycle, Electron Transport Chain
and Beta Oxidation It is in this system, fats more than carbohydrates (glucose) are
used to generate ATP. This process is called lipolysis. The fat produces more "energy"
(ATP molecules), but also requires more oxygen.
What Does It All Mean?
In order to burn more fat, the intensity level must be kept at a level that is sustainable
for long enough to move into the "fat burning zone" or Oxidative System.
Most people have about 2 hours of stored glycogen (glucose) in the muscle when
exercising at moderate intensity. So it's safe to assume that unless you are running a
marathon, you are using both stored glucose and fat when doing your aerobic
training. This applies to whatever type of aerobic training you choose.Weight training,
on the other hand, relies on stored available carbohydrate (glucose) because the
short duration/high intensity of each lift doesn't call for the body to burn fat for fuel.
The argument that low intensity long duration exercise burns a greater percentage of
calories from fat still stands. Example: a comparison of the calories expended by the
same person walking for 1 hour and jogging for 1 hour reveals that the walking burns
a much greater percentage of calories from fat although the overall calorie
expenditure is lower.
In terms of just pure calorie consumption during exercise – the more oxygen you use
the greater your calorie use. If we look at the Oxidative System which uses fat, but
requires more oxygen to do, we can infer that working out at medium intensity for
longer durations will burn more calories AND a higher percentage of fat.
The current thinking is that the more muscle groups engaged during the activity
(example: aerobic dance with arms and legs), the harder the body works requiring
more oxygen and more calories. Do it long enough, the body will burn a higher
percentage of fat.
There's a lot of discussion about the "afterburn" or the thermic effect of exercise
recovery. Yes, the body does burn energy to recover. A more intense workout
requires more energy to recover – hence more calories burned after the workout.
There are many fitness programs that advocate interval aerobics for fat burning.
There are just as many that advocate long duration aerobics for fat burning. I
advocate a combination of the 2. Both will burn fat. Each has benefits beyond fat
Interval training increases your cardiovascular strength, output, heart rate recovery
and produces a stronger "afterburn".
Long duration trains the cardiovascular system to sustain an increased load for a
longer period of time and teaches the body to convert fat to energy more efficiently
for use during exercise (endurance).
Whatever aerobic activity a person does, the key is to keep doing it. Why? The more
a person exercises, the more efficient the body becomes at converting and using
available carbohydrate and fat. So… regular aerobic exercise over a long period of
time is more important for fat and calorie burning than which method used.
Copyright (c) 2006 Ainsley Laing
About The Author
Ainsley Laing, MSc. has been a Fitness Trainer for 25 years and writes exclusively
Body for Mind eZine. She holds certifications in Group Exercise, Sports Nutrition and
Personal Fitness Training. To see more articles by Ainsley visit
Over the weekend, a really good
friend was discussing how he
"just can't seem to lose 2 kilos".
He feels that it is fat weight and
we discussed ways in which he
can change his workout to
optimize fat loss. This got me
started thinking about how many
different methods of fat loss and
fads have come and gone over
the many years that I have been
a fitness instructor.
If there is one thing I have
learned – exercising regularly
over time will work to burn fat.
|Copyright © EveryNutrient.com
|These statements have not been evaluated by the Food and Drug Administration (FDA). The content on
this website is for educational purposes only. Please consult with your physician before using natural
remedies and before making any drastic changes to your diet or exercise program.
Extra-Virgin Coconut Oil
Coconut Oil Reviews
Coconut Oil Research