The document describes the three main energy systems in the body: 1) The immediate/ATP-CP system provides energy for bursts of intense activity lasting 1-10 seconds through breaking down creatine phosphate. 2) The short-term/anaerobic system provides energy for higher intensity exercise lasting 10-120 seconds through breaking down glycogen and glucose to produce lactic acid. 3) The long-term/aerobic system provides sustained energy for activities lasting 2-10 minutes through aerobic breakdown of glucose and fatty acids to produce the most ATP.

1. Three energy systems:
Immediate energy system
(Creatine phosphate)
Short term energy system
(Lactic acid)
Long term energy system
(Aerobic)
(Figure 1) By Elizabeth Snodgrass

2. • Energy is a property of objects which can be transferred to
other objects or converted into different forms. The "ability of
a system to perform work" is a common description, but it is
misleading because energy is not necessarily available to do
work. (Wikipedia, 2016)
(Figure 2)

3. Law of Thermodynamics: Energy
is neither created of destroyed,
it is only transferred from one
form to another. - Boundless
Chemistry. Boundless, 02 Jun. 2016.
(Figure 3)
(Figure 4)
(Figure 5)
(Figure 6)
Light and
heat energy
Photosynthesis
Chemical
carbohydrates
Carbohydrates,
lipids, proteins
ATP

4. • Energy is in the form of ATP
• ATP is found in every cell, mainly in the
mitochondria
Energy released
when bond breaks
(Figure 7)

5. • When energy is released, Adenosine Triphosphate (ATP) loses
a phosphate due to the bond breaking, becoming Adenosine
Diphosphate (ADP). ADP then loses a phosphate, becoming
Adenosine Monophosphate (AMP)
• Each time the bond breaks, energy is released
Adenosine Triphosphate
Adenosine Diphosphate
(Figure 7)
(Figure 8)

6. • ATP is easily regenerated due to phosphate
molecules being readily available
• Therefore, more energy can be generated in the
muscles during exercise
(Figure 9)

7. • Also known as the Immediate energy system or the phosphocreatine system
• ATP is stored in the muscles and can be made without the presence of oxygen making it anaerobic
• A phosphate bond is then broken, creating energy therefore, ATP becomes ADP.
• A creatine phosphate molecule then bonds to the ADP, exchanging the phosphate molecule and becoming
ATP, the creatine is then on its own
• The Creatine phosphate system is used when energy is required instantly during high intensity exercises
• For example, power sports such as shot put and high jump will use this energy system because ATP is
required immediately to perform the burst of movement
ADP + PCr → ATP + Cr
Training and diet increase the levels of Creatine phosphate, as well as Creatine supplements
(Figure 10)

8. • Also known as the short term energy system
• This system is used for higher intensity exercise and last over a longer period of time
• For example, at the start of a cross country race this energy system is accessed to get in to a good
position
• It uses glycogen which is stored in the liver and muscles. The glycogen is then transferred in to glucose.
• Glycolysis then takes place, which produces ATP, transferring glucose in to pyruvic acid then lactic acid.
• This lactic acid then builds up in the blood as intensity increases
• This is an anaerobic energy system as it is made without the presence of oxygen
• The lactic acid system is required when the intensity is higher than the aerobic capacity. Generally at the
beginning of exercise
Glucose + → pyruvic acid → Lactic acid
Glycogen
Gluconeogenesis (Resting)
Training increases the lactic acid tolerance, therefore increasing performance (Figure 11)
Glycolysis Reduction (gain H+
ADP → ATP

9. • Also known as the long term energy system
• The system is accessed when exercise lasts over a longer period of time at a lower intensity
• For example, exercises that require oxygen such as during a cross country event and a 90
minute football match, which is are aerobic events
• Glycogen is stored in the muscles and glucose is transferred through the blood. Glycolysis
then takes place, which produces ATP, transferring glucose in to pyruvic acid.
• The Krebs cycle then takes place. ADP combines with oxygen forming ATP, carbon dioxide and
water. ATP is used for energy, carbon dioxide and water are both water products of the cycle
Glycogen + Glucose → pyruvic acid
Training increases the number of mitochondria and oxygen supply
O2 + ADP → ATP + CO2 + H2O
(figure 12)
Glycolysis

10. Energy System Molecule ATP produced
Immediate Creatine phosphate 1
Short term Glucose 2
Short term Glycogen 3
Long term Glucose 38
Long term Fatty acids 129
The immediate energy system only produces ATP from creatine phosphate molecules, whereas the
short term energy system produces ATP from both glycogen molecules and glucose molecules, in
contrast to the long term energy system producing energy from both glucose and fatty acid
molecules. Creatine phosphate only produces 1 ATP, glycogen produces 3 ATP and fatty acids
produce 129 ATP.
• Creatine phosphate immediately produces ATP because it is supplied in the muscle.
• Glucose and glycogen in the short term energy system, produces little ATP at a slower rate than
the immediate energy system as glucose is transferred in the blood and glycogen is stored in
the muscles but needs to be transferred in to glucose.
• Glucose and fatty acids in the long term energy system, produces the most ATP, but slowly as
glucose is transferred through the blood and the fatty acids are broken down.

11. Duration Classification Energy supplied
by…
Example
1 to 4 seconds Anaerobic ATP (in muscles) Shot put
4 to 10 seconds Anaerobic ATP + CrP Javlin
10 to 45 seconds Anaerobic ATP + CrP + muscle
glycogen
100 meters
45 to 120 seconds Anaerobic, lactic Muscle glycogen 400 meter hurdles
120 to 240 seconds Aerobic and
anaerobic
Muscle glycogen,
lactic acid
Boxing
240 to 600 seconds Aerobic Muscle glycogen +
fatty acid
3000 meter

12. References
Figure 1 - http://s.hswstatic.com/gif/sports-physiology-atp.gif
Wikipedia, 2016 - https://en.wikipedia.org/wiki/Energy
Figure 2 - https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Energy_and_life.svg/2000px-
Energy_and_life.svg.png
Figure 3 -
https://www.google.co.uk/search?q=outline+of+a+person&biw=1366&bih=673&source=lnms&tbm=isch&sa=X&ved=0
ahUKEwir84Kp6KDQAhXUFsAKHUzlAWsQ_AUIBigB#tbm=isch&q=sun&imgrc=AF41JzlTwMvN4M%3A
Figure 4 -
https://www.google.co.uk/search?q=outline+of+a+person&biw=1366&bih=673&source=lnms&tbm=isch&sa=X&ved=0
ahUKEwir84Kp6KDQAhXUFsAKHUzlAWsQ_AUIBigB#tbm=isch&q=grass&imgrc=3dynYNQxHiWxqM%3A
Figure 5 -
https://www.google.co.uk/search?q=outline+of+a+person&biw=1366&bih=673&source=lnms&tbm=isch&sa=X&ved=0
ahUKEwir84Kp6KDQAhXUFsAKHUzlAWsQ_AUIBigB#tbm=isch&q=cow+clipart&imgrc=Qj-oVH74UePEcM%3A
Figure 6 - http://www.clipartbest.com/cliparts/RTA/6jG/RTA6jGLbc.png
Figure 7 – http://study.com/cimages/multimages/16/ATP.jpg
Figure 8 - http://leavingbio.net/ENERGY%20FOR%20LIFE_files/image001.gif
Figure 9 - http://www.thealevelbiologist.co.uk/_/rsrc/1379087920084/atp/ATP-ADP-CYCLE.gif
Figure 10 - http://pages.uoregon.edu/mdillon1/Energy%20Metabolism/imageIE8.JPG
Figure 11- https://classconnection.s3.amazonaws.com/981/flashcards/598981/jpg/anaerobic1311123983968.jpg
Figure 12 - https://s-media-cache-ak0.pinimg.com/736x/0d/b2/78/0db278ddec05ac11c915a8250c56eb7e.jpg
Boundless Chemistry. Boundless, 02 Jun. 2016. - https://www.boundless.com/chemistry/textbooks/boundless-
chemistry-textbook/thermodynamics-17/the-laws-of-thermodynamics-123/the-three-laws-of-thermodynamics-496-
3601/