The human body is made to move
in many ways
• Quick and powerful
• Graceful & coordinated
• Sustained for many hours
• Quick movements-lasts a few
seconds
• Reduced speed-lasts for several
minutes
• Reduced intensity(50%)-lasts for
several hours
The body uses different energy systems for
each activity dependent upon the capacity to
produce energy
The human body has
three main systems for
producing energy for our
physical activity
1. Anaerobic Alactic
2. Anaerobic Lactic
3. Aerobic
Cells in the body
need energy to
function
FOOD=ENERGY
(E)
Each system works independently or in unison
with the others depending on the type of activity
we are doing
Each these systems provide the body with energy
by producing ATP (energy currency)
Cells don’t get Energy
directly from food, it must
be broken down into:
ATP- Adensosine TRI
phosphate
ATP = a form of energy one
can immediately use, it is
needed for cells to
function & muscles to
contract
Our body cant carry the
amount of energy needed, so
has systems in place to
produce ATP
Our body uses food/fuel to
help produce the ATP required
for our bodies needs
• Glucose = Glycogen
(muscle & liver)
• Fatty Acids = Body fat
• Amino Acids =
Growth, repair or
excreted as waste
ATP is stored in
small amounts,
therefore the rest
is stored as:
• ATP (2-3 seconds)
• ATP-CP Energy System
(8-10 seconds)
• Anaerobic Energy
System (2-3 minutes)
Predominant
Energy Pathways
Aerobic Energy System (3 minutes +)
ATP is stored in the muscle & liver
for “Quick Energy”
• Nerve impulses trigger
ATP-CP Energy
breakdown of ATP into ADP
System
• ADP = Adenosine Diphosphate &
1 Phosphate
• The splitting of the Phosphate
bond = Energy for work
Ex. Muscle Contraction, Moving
hand from a hot stove, Jumping
& Throwing
For contractions to continue… ATP
must be REBUILT
This comes from the splitting of CP
(Creatine Phosphate a Hi energy
source, automatic)
When ATP is used – it is rebuilt – as
long as there is CP
Energy released from CP breaking
down, resynthesizes the ADP & P
ATP-CP = 8-10 sec. of
Energy
The usefulness isn’t the
AMOUNT of Energy but the
QUICK & POWERFUL
movements
For longer periods of work
= The Aerobic & Anaerobic
Energy System must be
utilized
REMEMBER –
only small
amounts of
ATP are
stored = only
2-3 sec. of
Energy
• Without oxygen = Activities that
require a large burst of energy
over a short period of time
• Anaerobic Glycolysis =
Production of ATP from
Carbohydrates without oxygen
(breakdown of glucose) Since
glycogen is stored in the muscle
& liver, it is available quickly
This system provides ATP when
ATP-CP runs out
Anaerobic
Energy System
 1. The process to produce ATP is
not as fast as ATP-CP, which
makes muscle contraction slower
 2. When oxygen is not present
the end product of glycolisis is
lactic acid, which causes the
muscles to fatigue
 3. Anaerobic Glycolisis is less
efficient in producing ATP than
Aerobic Glycolisis, BUT is
needed for a large burst of
energy lasting a few minutes
Again, ATP-CP
lasts for a few
seconds, the
Anaerobic Energy
System allows for
2-3 minutes of work
Glucose = 2ATP + 2LA
(digested component of
carbohydrates)
Glycogen = 3ATP + 2LA (the
storage form of glucose)
Without
Oxygen
 Glucose + O2 = 36ATP + H2O + CO2
 Fatty Acids + O2 = 129ATP
 Body Fat is a great source of ENERGY
With
Oxygen
Oxygen Deficit = The body can not supply
enough O2 to the muscles that the muscles
demand
• When the muscle does not get enough oxygen,
exhaustion is reached causing immediate and
involuntary reduction in intensity
Oxygen Debt = “pays back” the deficit
recovery time
aerobic Energy System
• With Oxygen = Using large muscle groups
continuously over a period of time
• Aerobic Glycolisis & Fatty Acid Oxidation =
The production of ATP from Carbohydrates &
Fat
1. O2 enters the system, stopping the
breakdown of glycogen to lactic acid
2. With oxygen, glycogen breaks down into: ATP +
CO2 + H20
3. These byproducts are easier to get rid of CO2 is
expelled by the lungs H20 is used in the muscle
4. Anaerobic Energy System = Carbohydrates are
the only fuel source
5. With prolonged exercise, Carbohydrates are the
first fuel choice, as exercise continues, FAT
becomes predominant
6. Protein is not a main fuel source except in an
emergency
Each system plays an important role
in energy production
This gives us a variety of movements
The systems interact to supply
Energy for the activity