ENERGY SYSTEMSYEAR 13 Physical Education

By the end of today you willBe able to: Understand and explain how ATP is used

to create energy Explain the role of food in the

production of ATP Identify the role each system plays in

exercise

How do we get energy? Food is the basic source of energy

3 basic nutrients: Carbohydrates – Fat – Protein –

Carbohydrates

Broken down as glucose and stored as glycogen in the muscles or liver

Carb’s are preferred source of energy and can be used to produce energy with or without oxygen

Glycolysis – break down of Glycogen

Fats

Broken into triglycerides or Free Fatty acids

Stored as adipose

Used during aerobic exercise (long runs) Lipolysis – break down of fats (lipids)

Protein Broken into amino acids

Used to create tissues ‘

Only used in extreme cases

Why?

Food as an energy source?

Our body uses molecule called ATP to gain energy.

ATP = Adenosine Triphosphate

When ATP molecule breaks energy is released

Only a small amount is stored at the muscle e.g to complete a 5m sprint or jumping up.

ATP must be continually rebuilt so energy can be provided for a long period of time.

3 Energy Systems There are three ways our muscles get

energy/fuel:

1. ATP 2. ATP-CP

3. Lactic Acid (Lactate system) 4. Aerobic system

We don’t jump from one energy system to the next we change all the time throughout activity.

ATP - ADP Energy for muscle contraction comes from the

breakdown of ATP

The 3 (Tri) phosphate muscles are the key to the release of energy

As a phosphate molecule is split, energy is released

ATP is broken down in the muscles – as muscles are the site of the action

ATP and ATP-CP ATP is used for first 3sec - THEN CP (Creatine phosphate) is added to replenish the ATP

for 3-10sec Adenosine Tri Phosphate = Adenosine Di Phosphate +

energy(ATP)

=

ATP/CP system Energy supply is immediate, can supply large amounts

of ATP for short, high intensity, explosive activities. The higher the intensity the quicker CP stores are used up. After 5 secs CP stores are depleted by up to 50%. Cp powers movement for between 6 to 8 secs. Without this system actions such as sprints, explosive throws/jumps would not be possible.

The ATP/CP system provides energy for maximum muscle contraction of up to 10-15 seconds. To replenish the system by up to 70 %, requires 30 secs rest and up to 8 minutes to fully restore. [95-100% HR]

Lactic acid [anaerobic glycolysis system] CHO we eat are broken down to glucose and this is used to

fuel activity. Glucose is much more plentiful than CP. In the process of using glucose, lactic acid is a by product. This can lead to muscle fatigue/soreness/burning if lactate threshold is reached.

With a rise in acidity glucose production is hindered and acid inhibits calcium binding. Without sufficient calcium muscles cannot contract.

The lactic acid system is activated at the start of intense exercise. Its peak power is usually reached after 15 secs but the system contributes ATP until it fatigues after about 2/3 minutes [depending on intensity]

Recovery ranges from 20 min to 2 hours. [85-100% HR]

Aerobic system This is the most powerful of the systems as it has the

greatest capacity to produce ATP and produces the most energy.

As the lactic acid system decreases it becomes the major ATP contributor.

It supplies energy for extended endurance activities that remain below 85% [marathon]

. Recovery 2-5 days depending upon extent of fitness/

exertion/diet/ how soon CHO taken in after.[60-85% HR]

Aerobic Glycolysis Aerobic means? Glycolysis means? Aerobic Glycolysis means what?

Glycogen breaks down to Glucose

sufficient oxygen present

Energy to break down more ATP