Energy Expenditure/ Energy Balance
It can be measured in either calories and
joules. One calorie is defined as the amount
of energy, or heat, needed to raise the temp
of 1 litre of water by 1.c. In Britain we use
calories, but should be referred to as
Kilocalories or Kcal. The international unit for
energy is joule or kilojoule
1kcal= 4.2 joules
1g carbs = 4 Kcals
1g Proteins = 4 Kcals
1g fat = 9kcals
The body is composed of two elements:
◦ 1. Lean body tissue (ie. Muscles, organs, bones,
◦ 2. Body fat (or adipose tissue)
The proportion of these two components in
the body is called body composition
This is more important than total weight
This measures you’re
Calorimetry is the
science of measuring
the heat of chemical
reactions or physical
Calorimetry involves
the use of a
Directly measures energy produced by combination
of food with oxygen
Involves the burning of food in a controlled way,
and measuring heat energy produced
Heat energy is measured by observing the rise in
temperature of a quantity of water heated by the
burning food.
Alternative: Measure body’s heat production in a
calorimeter chamber
◦ The heat energy created by the subject radiates to the walls
and heats the water.
◦ Temperatures of incoming and outgoing water and air are
recorded and used to calculate BMR and total energy
Uses the fat that every atom of carbon in food
combines with a molecule of oxygen during
the chemical reaction to produce one
molecule of carbon dioxide and release a
definite and constant amount of energy.
Method involves the measurement of the
amount of oxygen consumed – which can
therefore be related to the amount of energy
released by food
Basal Metabolic Rate (BMR) is the minimal
caloric requirement needed to sustain life in a
resting state. This is the amount of energy
that your body requires if you slept and
rested all day. A variety of factors impact this
affect the BMR, some speed it up and some
slow it down they are;
Age: The older you get the
less you require
Muscle mass: The more
you have, the higher the
BMR as lean tissue needs
more energy that fat
Body size: taller heavier
individuals need a higher
BMR to fuel them
Growth: Children and
Pregnant women need a
higher BMR
If you are ill (high temp)
or stressed, you also
To calculate your BMR you will need to follow
this link;
To work out your total expenditure
throughout your day use this;
Energy is expended in a number of
different ways such as resting metabolic
rate, thermic effect of activity,
Your energy balance is the balance of
calories consumed through eating and
drinking compared to calories burned
through physical activity. What you eat
and drink is energy in. What you burn
through physical activity is energy out.
You burn a certain number of calories
just by breathing air and digesting food.
You also burn a certain number of
calories through your daily routine.
An important part of maintaining energy
balance is the amount of physical activity
that you do. People, who are physically
active, burn more calories than people
who are not as physically active.
A sports person would want to
be in balance when they are at
their normal training day and
not looking so massive gains.
This is mainly referring to any
sports person who wants to
stay at their optimum weight.
When they would want to make
massive gains in their training
they would want to increase the
intake compared to the
When wanting to loose weight
you need to take less in than
you use up
Catabolism refers to the
breaking down of stuctures
in the body. Training
(especially in a gym)
causing a lot of this due to
the damage and stresses
put on the muscles. You
will often feel stiff and sore
after training as your body
is in a catabolic state. You
need to ensure you replace
the energy lost and aid the
recovery/ repair process
with your meals
Post training
meals, rest
and recovery
are when your
body grows
bigger and
stronger. This
is vital to any
Talk through the energy obtained from each
type of food
How you assess body composition
How to measure you requirements
Your BMR and activity contribution to energy
Energy Balance and expenditure (Catabolic,
Anabolic State)

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