Energy systems

Question 1

Glycogen sparing

Answer 1

Allows athletes to use fats at higher intensities and more readily at beginning of exercise and throughout.
Results in less use of glycogen earlier in the event meaning that it can be used later when intensities increase

Question 2

The contribution of each energy system depends on:

Answer 2

• Duration of exercise
• Intensity of exercise
• If oxygen is present
• Depletion of other fuels

Question 3

The 3 energy systems

Answer 3

ATP-PC system
Aerobic Glycolysis
Anaerobic system

Question 4

Rate

Answer 4

How quickly ATP is resynthesized

Question 5

Yield

Answer 5

Total amount of ATP that can be resynthesized from particular energy system

Question 6

Fatigue

Answer 6

Refers to what inhibits the function of the energy system and forces a reduction in intensity

Question 7

Intensity

Answer 7

The level of exertion being applied to an activity. Relates to the exercise intensity at which an energy provides the most ATP

Question 8

Capacity

Answer 8

The ability of an energy system to continue to resynthesise ATP without fatiguing

Question 9

Finite capacity

Answer 9

means that the energy systems will fatigue rapidly and can no longer produce enough ATP until recovery

Question 10

Relatively finite capacity

Answer 10

means the energy system can continue to resynthesise ATP for an extended period of time

Question 11

ATP-PC system characteristics

Answer 11

The ATP-PC system produces energy by breaking down the fuel PC. The chemical reaction does not require oxygen making the ATP-PC system an anaerobic energy system.
The ATP-PC system fuels explosive or maximal intensity actions or movements that are short in duration
ATP-PS system has a finite capacity meaning it will fatigue rapidly and reduce its contribution to ATP re-synthesis
ATP-PS systems fatigues when PC stores are depleted
PC can be replenished and used again during an exercise bout but this is done during periods of rest or low intensity exercise
Used at maximal intensity

Question 12

Anaerobic Glycolysis System characteristics

Answer 12

• Produces energy through the incomplete breakdown of glucose and pyruvic acid is left as a by product. Without oxygen, pyruvic acid is converted into lactic acid and H+ ions
• It doesn’t require oxygen and occurs when oxygen isn’t available
• Anaerobic glycolysis system is used at very high intensities (85%> max heart rate)
• Due to H+ ion accumulation we will fatigue and be forced to reduce intensity
• Anaerobic system works at a rapid to fast rate however not as rapid as ATP-PC system
• The Anaerobic glycolysis system has a low yield (2-3 ATP) because of fatigue.
• Finite capacity because of fatigue
• H+ ions can be oxidised but this can only happen at periods of rest or low intensity exercise

Question 13

Aerobic system

Answer 13

• produces energy by break down of fuels glucose and fats
• aerobic system fuels submaximal intensity exercise that are longer in duration
• Aerobic system cannot produce ATP as quickly but we can get alot more ATP from this process
• glucose is broken down completely by using oxygen to produce ATP
• The body’s glycogen stores can last 90-120 minutes. After depletion, fats become dominant fuel. Fats have slower rate and higher oxygen cost than glycogen so intensities must decrease when switching to fats
• Switching from glycogen to fats is a form of fatigue because intensities are reduced greatly
• The A.G. system has a relatively infinite capacity due to high levels of fuel source and non-fatiguing by products associated with the breakdown of fuels

Question 14

ATP demand

Answer 14

refers to how much ATP is required during an activity and the rate at which it is used and therefore needs to be resynthesized
During an activity, ATP re-synthesis must meet ATP demand of the activity or we will have to reduce intensity of the activity
- ATP demand is dependent on duration and intensity of exercise
- As intensity and duration of activity increases, ATP demand increases
- There is a linear relationship between both intensity and ATP demand and duration and ATP demand

Question 15

What you should remember all the time

Answer 15

All three energy systems contribute to ATP re-synthesis all the time but their relative contributions will vary based on duration and intensity of exercise.

Question 16

Interplay of energy systems

Answer 16

• How each system works alongside the other energy systems together
• How much an energy system contributes to ATP re-synthesis will depend on two things: intensity and duration of exercise

Question 17

Relationship between exercise duration and intensity

Answer 17

• inversely proportional
• as exercise intensity increases, duration decreases (because we fatigue a lot sooner when we increase intensity)
• as exercise duration increases, exercise intensity decreases ( in order for us to exercise for long periods of time, we need to do so at a low intensity- submaximal intensity)

Question 18

Oxygen Deficit

Answer 18

The period of time where oxygen supply does not meet oxygen demand.
While oxygen deficit continues, the body must obtain ATP from anaerobic systems

Question 19

Steady state

Answer 19

When oxygen supply meets oxygen demand, the body is said to have reached a steady state
During steady state, the aerobic energy system becomes the major supplier of ATP

Question 20

Oxygen debt or EPOC

Answer 20

At completion of exercise, the demand for ATP decreases dramatically, however oxygen consumption is still higher than resting levels. This is referred to as EPOC
During EPOC, oxygen supply exceeds demand, the purpose of EPOC is to restore the body back to pre-existing levels

Question 21

Oxygen consumption and exercise types

Answer 21

Activities that are high intensity and rely heavily on anaerobic systems will have a 
- large oxygen deficit
- a brief or no steady state
- a large EPOC
Activities performed at low intensities
- smaller oxygen deficit
- a longer steady state
- a smaller EPOC