Energy Systems
The body’s ability to extract energy from food and transfer it to the contractile proteins in the
muscles determines your capacity to exercise for different durations at different intensities.
The body maintains a continuous supply of energy through the use of adenosine
triphosphate. Which is often referred to as the energy currency of the body. Adenosine
triphosphate is a molecule that stores and releases chemical energy for use in the body.
Energy is required in order to make the muscle fibres contract. Carbohydrates are broken
down into a simple sugar called glucose, which if not required immediately by your body is
converted into glycogen and stored in the liver and muscles. Fat is broken down to form free
fatty acids.
Phosphate Creatine - Adenosine triphosphate and phosphocreatine make up the ATP-PCr
system. It is a high energy compound, and when you exercise at high intensities or are in
need of energy instantly the creatine phosphate which is stored in muscles is broken down
to provide energy and make adenosine triphosphate. It is usually made without the presence
of oxygen. Explosive work can be achieved for only 10 seconds at maximum intensity as the
supply of PCr is limited.
ADP + creatine phosphate ---> ATP + creatine
Lactic acid energy system - This is a short term energy system. To meet energy
requirements of higher intensity over a longer period, such as during a 400 metre race, ATP
can be made by the partial breakdown of glucose and glycogen. This is an anaerobic
process that does not require oxygen and therefore is not sustainable over a long duration.
Around 60-90 seconds of maximal work is possible using this system.
Lactic acid production is the limiting factor of the anaerobic system. It accumulates and
diffuses into the tissue fluid and blood. If this substance is not removed by the circulatory
system, it builds up to impede muscle contraction and cause fatigue. This is when your
muscles have a burning sensation during an intense exercise which usually occurs nearing
the end of the football game when muscles are fatigued and tired.
Aerobic Energy - This is the long term energy system. If plenty of oxygen is available, as it
is during everyday movements and light exercise, glycogen and fatty acids break down to
yield large amounts of ATP. This produces carbon dioxide and water, which do not affect the
ability of muscles to contract. Aerobic energy production occurs in the mitochondria of the
cells. These are the power stations of the cells, responsible for converting food into energy.
The production of energy within the aerobic system is slow to engage because it takes a few
minutes for the heart to deliver oxygenated blood to working muscles. Long, continuous and
moderate exercise produces energy using this system.
Sport Creatine phosphate Lactic acid energy Aerobic energy
The body’s ability to extract energy from food and transfer it to the contractile proteins in the
muscles determines your capacity to exercise for different durations at different intensities.
The body maintains a continuous supply of energy through the use of adenosine
triphosphate. Which is often referred to as the energy currency of the body. Adenosine
triphosphate is a molecule that stores and releases chemical energy for use in the body.
Energy is required in order to make the muscle fibres contract. Carbohydrates are broken
down into a simple sugar called glucose, which if not required immediately by your body is
converted into glycogen and stored in the liver and muscles. Fat is broken down to form free
fatty acids.
Phosphate Creatine - Adenosine triphosphate and phosphocreatine make up the ATP-PCr
system. It is a high energy compound, and when you exercise at high intensities or are in
need of energy instantly the creatine phosphate which is stored in muscles is broken down
to provide energy and make adenosine triphosphate. It is usually made without the presence
of oxygen. Explosive work can be achieved for only 10 seconds at maximum intensity as the
supply of PCr is limited.
ADP + creatine phosphate ---> ATP + creatine
Lactic acid energy system - This is a short term energy system. To meet energy
requirements of higher intensity over a longer period, such as during a 400 metre race, ATP
can be made by the partial breakdown of glucose and glycogen. This is an anaerobic
process that does not require oxygen and therefore is not sustainable over a long duration.
Around 60-90 seconds of maximal work is possible using this system.
Lactic acid production is the limiting factor of the anaerobic system. It accumulates and
diffuses into the tissue fluid and blood. If this substance is not removed by the circulatory
system, it builds up to impede muscle contraction and cause fatigue. This is when your
muscles have a burning sensation during an intense exercise which usually occurs nearing
the end of the football game when muscles are fatigued and tired.
Aerobic Energy - This is the long term energy system. If plenty of oxygen is available, as it
is during everyday movements and light exercise, glycogen and fatty acids break down to
yield large amounts of ATP. This produces carbon dioxide and water, which do not affect the
ability of muscles to contract. Aerobic energy production occurs in the mitochondria of the
cells. These are the power stations of the cells, responsible for converting food into energy.
The production of energy within the aerobic system is slow to engage because it takes a few
minutes for the heart to deliver oxygenated blood to working muscles. Long, continuous and
moderate exercise produces energy using this system.
Sport Creatine phosphate Lactic acid energy Aerobic energy
