Characteristics of the Three Energy Systems.
Characteristics
ATP-PC Energy System
Alternative Name/s
Phosphagen system
ATP-CP system
Creatine phosphate system
Phosphate system
Anaerobic
Aerobic or Anaerobic
Anaerobic Glycolysis
Energy System
Lactic Acid system
Lactacid system
Aerobic Energy System
Oxygen system
Anaerobic
Aerobic
 Carbohydrates which
are stored as glycogen
within the muscles cells
and the liver.
 Carbohydrates- preferred
fuel during exercise.
 Fats- stored as triglycerides in
muscle cells and the liver.
Used predominantly when
body at rest and during lower
intensity exercise (up to about
50-65% of maximum oxygen
uptake).
 Proteins- only in extreme
circumstances such as
starvation or ultra endurance
events.
 Slowest system to provide
energy for ATP resynthesis
due to complex nature of its
chemical reactions, and the
fact that sufficient oxygen has
to be made available to the
muscle cells.
 1.0 mol per minute.
Fuel/s Used
 Phosphocreatine (PC)
also known as creatine
phosphate which is stored
in small quantities within
muscle cells.
Maximal Rate of
Energy Production
 Fastest rate of energy
 Provides energy for ATP
release for resynthesis of
resynthesis rapidly, but
ATP from ADP and Pi.
not as quickly as the
ATP-PC system.
 3.6 mols per minute
 This is because this system  1.6 mols per minute.
is the least complicated of
 This is due to a more
the three energy systems
complex series of
(fewer chemical steps) and
chemical reactions which
because PC is found within
results in glycogen
the muscle cells
breaking down to glucose
themselves.
and then to pyruvic acid
and then eventually to
lactic acid.
Maximum ATP
Production (Yield) per
mole of fuel source
 Small amounts of ATP
produced.
 Less than one mole of ATP
per mole of
phosphocreatine.
 Approximately twice as
much ATP produced as
the ATP-PC system.
 Approximately 2 mols of
ATP per mol of glycogen.
Duration and Intensity
of Peak Energy
Production
 Activated at the beginning
of high intensity exercise.
 Predominant energy
supplier within the first 5
seconds of high intensity
exercise, but its capacity is
depleted after 5-15
seconds of maximal
intensity exercise.
 Also activated at the
beginning of high
intensity activity.
 Predominant energy
contributor for ATP
resynthesis from the time
when the phosphagen
system is rapidly
depleting up until about
30-75 second during high
intensity exercise.
 May also become
predominant producer of
energy for ATP
resynthesis during
repeated short duration
maximal intensity efforts
which have insufficient
recovery time to allow for
full replenishment of
phosphocreatine stores.
Specific Examples
 Athletic field events (eg.
high jump, shot put)
 Short sprints
 Tennis serve
 Gymnastics vault
 Golf drive
 200 and 400 metre
athletic events.
 50 metre swim.
 High intensity tennis rally
of 15-20 seconds
duration.
 Vastly greater amounts of
ATP produced as compared
to the two anaerobic systems.
 38 mols of ATP from one mol
of glycogen.
 Over 100 mols of ATP from
one mol of fat (but more
oxygen required).
 Also activated at the start of
high intensity exercise and will
become the predominant
supplier of energy for ATP
resynthesis during continuous
sub-maximal intensity
exercise which exceeds 1-2
minutes in duration.
 In a maximal effort lasting 75
seconds, equal energy is
derived from the aerobic and
anaerobic systems.
 Predominant supplier of
energy for ATP resynthesis
when at rest and during submaximal activity.
 As every duration increases
and intensity decreases, the
contribution of the aerobic
system to energy production
increases whilst that of the
anaerobic systems
diminishes.
 10 000 m athletic event.
 Marathon
 2000 m rowing event.
Mid field players in many team
sports (eg. Australian Rules,
Soccer).
Major Limiting
Factor/s (when
functioning
maximally)
 Depletion of
phosphocreatine stores
Metabolic ByProducts Produced
 Nil
Links to fitness
components






Muscular strength
Muscular power
Anaerobic power
Speed
Agility
Reaction time
 Changes in the intramuscular environment
associated with (but not
necessarily caused by)
an increase in lactate and
hydrogen ions (H+).
 Lactic acid- lactate and
hydrogen ions (H+).
 Accumulation of lactate and
hydrogen ions.
 Depletion of glycogen stores.
 Anaerobic power
 Local muscular
endurance
 Speed
 Muscular power
 Relevant to all fitness
components because it
provides the basis for
recovery in anaerobic type
tasks (strength, power, speed,
etc) or the bulk of energy
production for sub-maximal
activities.
 Carbon dioxide (CO2)
 Water