Definitions
Energy systems
Energy systems can be defined as systems that help resynthesis the
production of adenosine triphosphate (ATP) (Amezdroz et al, 2004).
Energy systems can be defined as systems that help restore adenosine
triphosphate (ATP) stores (Amezdroz et al, 2004).
These systems provide energy aerobically or anaerobically that allows an
individual to continue the contraction of their muscles by resynthesising the
production of ATP. The aerobic system does this by using oxygen and is
called the cardiorespiratory system. The anaerobic system does not require
oxygen and can be broken down into the two pathways of creatine phosphate
and lactic acid systems (Amezdroz et al, 2004).
These systems provide energy aerobically or anaerobically that allows an
individual to resynthesis adenosine phosphate stores required for various
exercises involving continued muscle contraction. The aerobic system
requires oxygen and the anaerobic system does not require oxygen for its two
pathways of creatine phosphate and lactic acid (Amezdroz et al, 2004).
ATP
ATP is a chemical compound that breaks down to release the energy
responsible for muscle contraction. It is the only useable form of energy in the
body (Quinn, 2007).
ATP is also responsible for important functions such as “secretion by organs,
cell division, active transport, nerve transmission, and muscular contraction”
(Amezdroz et al, 2004).
When ATP is broken down it releases energy for body functions such as
“secretion by organs, cell division, active transport, nerve transmission, and
muscular contraction” (Amezdroz et al, 2004).
ATP is a special chemical compound formed by the energy contained
in carbohydrates, fats and proteins to produce muscle contraction
(Amezdroz et al, 2004).
Aerobic system
The aerobic system can be defined as a system that is used for longer, less
intense, continuous activities of two minutes or more. It is also used during
rest periods after more intense activity in which aerobic energy is required to
rapidly repay oxygen debt and provide a complete recovery (Amezdroz et al,
2004).
The aerobic system is used during low intensity activities such as walking and
slow jogging (60% - 85% heart rate). Studies have shown that netball players
spend 23.5% of the match standing or resting which means that netball
players have an average work-to-rest ratio of 1:3 (Amezdroz et al, 2004).
The aerobic system can be defined as “exercise that uses oxygen to create
energy. It is usually sub-maximal and lasts for five minutes or more
(Amezdroz et al, 2004).
The aerobic system is used during rest periods where the minimal intensity
allows the heart rate to drop below 85% (Amezdroz et al, 2004).
Creatine phosphate system
The CP system can be defined as “ one of the basic muscle energy stores,
particularly in fast twitch glycolytic fibres. During exercise it is thought to be an
immediate source of high-energy phosphate groups with which to replenish
ATP, but only for the first few seconds of intense activity (Muscle
Physiology, 2006).
The CP system only supplies energy for high intensity activity such as sprints
that last no longer than ten seconds at 95% - 100% heart rate and do not
require oxygen (Amezdroz et al, 2004).
The CP system can be defined as a system in which the supplies are
exhausted after ten seconds of high intensity exercises and are not
replenished until after two minutes of rest (Amezdroz et al, 2004).
The CP system is present when activities are of maximal effort of 95% - 100%
heart rate. Activities of this intensity are generally short, fast, explosive
movements. (Amezdroz et al, 2004).
Lactic acid system
The lactic acid system can be defined as capable of releasing energy to
resynthesis ATP without the involvement of oxygen and is called anaerobic
glycolysis (Brian Mac, 1986).
The lactic acid energy system only provides energy for activities lasting from
thirty seconds to two minutes at 80% - 95% heart rate (Amezdroz et al,
2004).
The lactic acid system can be defined as the system that takes over from the
CP system when high intensity activity lasts longer than 20 – 30 seconds.
ATP is manufactured when glucose is broken down to lactic acid. Efforts are
of high intensity around 85% - 95% heart rate and lasts for 30 seconds to 2
minutes which draw energy (ATP) primarily from this system. (Amezdroz et
al, 2004).
2. Give a netball example to show the use of the following:
Aerobic system
An example is when I require high intensity energy when defending the ball
but will spend more time resting or shuffling back and forth, guarding the
opposition or getting into a good position.
An example is when I am substituted during a game, allowing the oxygen debt
to be repaid as the oxygen stores become available and the ATP stores are
replenished.
Creatine phosphate system
An example is when I sprint to defend the ball for five seconds or intercept a
pass by bursting out between the catcher and ball, only lasting for two to three
seconds
An example is when attacking the ball my dodges and rolls become quick and
explosive to break free from my opponent.
An example is when I use fast movements of the feet and a quick burst or
leap to intercept a ball when I am defending the ball.
Lactic acid system
An example is when the ball is turned over, play can be extended and efforts
of high intensity last longer than 20 seconds.