Energy systems

Question 1

What are the 3 stages of the aerobic system?

Answer 1

1. Glycolysis
2. Krebs cycle
3. Electron transport chain (ETC)

Question 2

Where does glycolysis occur?

Answer 2

In the sarcoplasm

Question 3

What happens during glycolysis?

Answer 3

Glucose is broken down into pyruvic acid
Pyruvic acid is split into 2 acetyl groups
Carried into Krebs cycle by coenzyme A

Question 4

Where does the Krebs cycle occur?

Answer 4

Matrix (mitochondria)

Question 5

What happens during the Krebs cycle?

Answer 5

Acetyl coenzyme A combines with oxaloacetic acid to form citric acid
Carbon released forms carbon dioxide (exhaled)
Fats entering Krebs cycle undergo beta oxidation

Question 6

What is beta oxidation?

Answer 6

Where fatty acids are broken down to generate acetylCoA

Question 7

Where does the ETC occur?

Answer 7

Cristae (mitochondria)

Question 8

What happens during the ETC?

Answer 8

Hydrogen carriers transport H to the ETC
H splits into H+ ions and electrons
H+ oxidised to form water (electrons re-synthesise ATP)

Question 9

How many molecules of ATP are produced during the aerobic system?

Answer 9

38
(glycolysis = 2, Krebs cycle = 2, ETC = 34)

Question 10

What are the 2 anaerobic systems better known as?

Answer 10

ATP-PC system
Anaerobic glycolytic system (lactic acid system)

Question 11

How long does the ATP-PC system last?

Answer 11

Between 8-10 seconds

Question 12

Write the coupled reaction of phosphocreatine (PC) and ATP?

Answer 12

Phosphocreatine (PC) —> Phosphate (Pi) + Creatine (C) + Energy
Energy —> Pi + ADP —> ATP

Question 13

How long does the anaerobic glycolytic system last?

Answer 13

Between 10-180 seconds

Question 14

What are the enzymes in the anaerobic glycolytic system?

Answer 14

Phosphofructokinase (PFK)
Lactate dehydrogenase (LDH)

Question 15

What is the energy continuum?

Answer 15

Shows which energy system is used for which type of physical activity / sport
Depends on intensity and duration of exercise

Question 16

How does the ATP generation differ between slow and fast twitch muscle fibres?

Answer 16

Slow twitch:
aerobic system
produces maximum ATP from each glucose
slower production but less likely to fatigue
Fast twitch:
lactate anaerobic system
not as efficient in absence of oxygen
faster production but more likely to fatigue

Question 17

What is the submaximal oxygen deficit?

Answer 17

When there is not enough oxygen is available at the start of exercise to provide all the ATP aerobically

Question 18

What is EPOC?

Answer 18

Excess Post-exercise Oxygen Consumption:
amount of oxygen consumed during the recovery phase of exercise

Question 19

How is lactic acid removed from the body after exercise?

Answer 19

Converted into protein
Removed in sweat and urine

Question 20

Explain how lactate accumulation causes muscle fatigue

Answer 20

Higher intensity = more lactic acid produced
Lactic acid breaks down quickly, releasing H+ ions
More H+ ions increases acidity
Slows down enzyme activity
Results in muscle fatigue

Question 21

What is the lactate threshold?

Answer 21

Point at which lactic acid is being produced faster than the rate it’s being removed from the body

Question 22

What is OBLA?

Answer 22

Onset of Blood Lactate Accumulation:
when lactate levels rise above 4mmol per litre

Question 23

Explain some of the factors that affect lactate accumulation

Answer 23

Exercise intensity —> higher intensity has greater demands for ATP, faster OBLA occurs
Muscle fibre type —> slow twitch produce less lactate than fast twitch
Rate of blood lactate removal —> lower rate allows more lactate to accumulate before OBLA

Question 24

How does buffering aid a sprinter?

Answer 24

Aids the removal of lactate
Maintains acidity levels in the blood / muscles
Therefore lower lactate levels

Question 25

Explain some of the factors affecting VO2 max

Answer 25

VO2 max increases 10-20% after aerobic training
VO2 is genetically determined
Men generally have a higher VO2 max than women
More body fat decreases VO2 max

Question 26

What is indirect calorimetry?

Answer 26

Measures carbon dioxide exhaled and oxygen inhaled during aerobic exercise
Precise calculation of VO2 max

Question 27

What is lactate sampling?

Answer 27

Measures lactate levels in the blood
Lower lactate levels mean performer has increased in speed
Increased time to exhaustion

Question 28

What is the VO2 max test?

Answer 28

Multi stage fitness / bleep test
Direct gas analysis —> measures oxygen inspired and carbon dioxide expired

Question 29

What is the Respiratory Exchange Ratio (RER)?

Answer 29

Ratio of CO2 produced : O2 consumed
Provides info about how much each energy source is being used
1 = purely carbohydrates
0.7 = purely fats
> 1 = anaerobic respiration

Question 30

What is altitude training?

Answer 30

Over 2500 metres above sea level
Oxygen has a lower partial pressure
Lower O2 carrying capacity

Question 31

Evaluate the pros and cons of altitude training

Answer 31

+ increased red blood cells
+ increased Hb concn
+ increased lactate tolerance
- expensive
- benefits can be lost quickly
- altitude sickness

Question 32

What is high intensity interval training (HIIT)?

Answer 32

Short intervals of maximum intensity
Followed by recovery intervals of low - moderate intensity
Higher intensity = anaerobic
Lower intensity = aerobic

Question 33

What is plyometric training?

Answer 33

Involves high intensity / explosive exercises
Works the fast twitch fibres
Improves speed and power

Question 34

Explain the 3 phases of plyometric training

Answer 34

1. Eccentric phase —> on landing, the muscle lengthens under tension
2. Amortisation phase —> time between the eccentric and concentric muscle contractions
3. Concentric phase —> uses stored energy to increase the force of contraction

Question 35

What is SAQ training?

Answer 35

Speed, Agility, Quickness
Improves multi-directional movement through developing the neuromuscular system
Uses activities performed with maximum force at high speed
Energy provided anaerobically