6. Energy Systems And Their Relation To Exercise

Question 1

What are the three main energy systems?

Answer 1

• Creatine phosphate
• Lactic
• Aerobic

Question 2

What energy-rich compound can be identified as our main currency?

Answer 2

Adenosine triphosphate.

Question 3

Describe how energy is released from ATP?

Answer 3

ATP release its energy when one of its two high energy bonds is broken (by the enzyme ATPase).

Question 4

What is the main energy system employed in sprinting?

Answer 4

Creatine phosphate.

Question 5

Which energy system require no oxygen?

Answer 5

Creatine phosphate.

Question 6

How are creatine phosphate stores replenished?

Answer 6

The body replenishes its supply of creatine phosphate from one of two sources – the liver and kidneys from amino acids or dietary creatine, primarily from meat and fish.

Question 7

Approximately how long does it take the body to replenish creatine phosphate stores?

Answer 7

ATP stores are 50% restored after 30 seconds and fully restored after about 5 minutes rest.

Question 8

For who long can the lactate system sustain activity?

Answer 8

The lactate system can supply the energy for higher intensity exercise activity for between 60 and 180 seconds.

Question 9

Give an example of an athletic event that would rely on lactate system.

Answer 9

400 metre race.

Question 10

Which energy system is dominate during lower-intensity activities?

Answer 10

Aerobic.

Question 11

Which energy system results in the incomplete breakdown of carbohydrate?

Answer 11

Lactic.

Question 12

The use of which energy system can result in the characteristics ‘burning’ sensation in muscles?

Answer 12

Lactic.

Question 13

Which energy system involves the complete breakdown of carbohydrate and fats?

Answer 13

Aerobic.

Question 14

What are the by-products of the aerobic energy system?

Answer 14

The aerobic system produces carbon dioxide, water and heat as by-products of the breakdown of CHO and fat.

Question 15

Give three examples of training adaptations through aerobic training.

Answer 15

• Pulmonary - improved efficiency of the respiratory muscles.
• Cardiovascular – significant hypertrophy and improved coronary blood flow.
• Muscular – a greater ability

Question 16

What are the main training adaptations targeted at the CP system?

Answer 16

To increase muscle size (fast twitch fibres) and improve activation of the muscle by the nervous system.

Question 17

What is lactate tolerance and how is it improved?

Answer 17

Lactate tolerance is the body’s ability to withstand the build-up of lactic acid which can be improved by regular anaerobic training.

Question 18

Energy currency

Answer 18

• Energy is required for movement, heat generation and tissue growth and repair.
• In the body, energy exists in the form of Adenosine Triphosphate (ATP).
• Carbohydrates, proteins and fats are all sources of energy.
• ATP supply must meet the demands of exercise in order for it to continue.

Question 19

Structure of ATP

Answer 19

• ATP is made up of one adenosine molecule and three phosphate ones.
• Energy is stored in the bonds that link the phosphate molecules to the adenosine.
• The bonds are broken down by the enzyme ATPase to release energy.
• Muscle ATP stores are limited, so they must be continually replenished by the creatine phosphate, lactate and aerobic energy systems.

Question 20

Creatine phosphate system – immediate energy

Answer 20

• Energy for muscular contraction is required quickly for high-intensity, low duration activities.
• The energy is supplied by intramuscular (inside the muscle) stores of ATP and creatine phosphate.
• ATP and creatine phosphate stores only last for a few seconds – such high intensities can’t be sustained for much longer than this.
• This system is derived exclusively from chemical energy stored in the muscles and requires no oxygen (i.e. it’s anaerobic).

Question 21

Lactate system

Answer 21

• Lactate system bridges the gap between the aerobic and creatine phosphate systems.
• Allows rapid ATP production to continue beyond the first few seconds of the creatine phosphate system.
• Can sustain exercise activity for 60-180 seconds.
• Waste products of this process can bring about a decline in performance with recovery times ranging from 20 minutes to two hours.

Question 22

Aerobic system

Answer 22

• The aerobic energy system produces ATP from the complete breakdown of carbohydrate and fat, in the presence of oxygen.
• Its by-products are carbon dioxide, water and heat.
• No limits on the amounts of ATP that can be produced but the rate of ATP production is limited.
• Recovery time will be the time taken to eat, drink and replenish fuel stores.

Question 23

Lactate training adaptations

Answer 23

• Lactate training adaptations are related to improvements in the cardiorespiratory system.
• Muscles that utilise more oxygen will produce less lactic acid at a given exercise intensity.
• Regular anaerobic training improves tolerance to waste products.

Question 24

Creatine phosphate training adaptations

Answer 24

• High-intensity activities have a significant training effect.
• They can result in increased muscle mass and a predominance of fast twitch muscle fibres.
• They may also increase muscular stores of anaerobic fuel sources.

Question 25

Interaction of energy systems

Answer 25

• There is considerable overlap between the three energy systems.
• All three systems could potentially provide the body with energy simultaneously.
• As the demands of the activity change, so do the relative contributions of the energy systems.