U3AoS2 - How does the Body produce energy? Flashcards
1
Q
Name the Food Fuels
A
Carbohydrates
Fats
Proteins
2
Q
Provide examples of Carbohydrates
A
Sugars
Starches
Bread
Pasta
Fruit
Vegetables
Jube lollies
White rice
3
Q
Yield definition
A
Number of ATP resynthesised per molecule.
4
Q
What is the yield of Carbohydrates?
A
36 ATP Molecules
5
Q
Describe Fats
A
Preferred food source at rest and during prolonged submaximal exercise
6
Q
Examples of fats
A
dairy products
oils
nuts
meat
butter
avocado
cheese
7
Q
Yield and Oxygen cost of Fats.
A
Yield = 441
Oxygen cost (L/mole) = 5.5 (great oxygen cost)
8
Q
Examples of protein
A
Meat, fish, eggs, legumes, and grains
9
Q
Role and definition of Fuel/Substrates
A
Used to provide energy to resynthesise ATP from ADP + Pi.
10
Q
Food fuel sources during rest:
A
- energy demand is low
- spare glycogen
- fats are main energy source
11
Q
High and Low Gi Foods
A
Body doesn’t digest and absorb all carbohydrates at the same rate.
12
Q
Glycaemic Index
A
Indicator of how quickly glucose is broken down and released into the blood stream over a 2-hour period of time.
13
Q
ATP
A
Adenosine Triphosphate
14
Q
ATP definition
A
- only energy source for muscular contractions
- splits when a phosphate group is removed
- Split releases energy required for muscular contractions to occur
15
Q
Following the Breakdown of ATP
A
- For exercise to continue ATP needs to be resynthesised.
- Chemical energy provided by the breakdown of the bodies available fuel allows for this process to occur
16
Q
ATP cycle
A
The constant process of ATP breakdown and resynthesis
17
Q
What is the role of the energy systems in ATP resynthesis?
A
- All 3 energy systems and fuels contribute to the resynthesis of ATP at all times for muscle contraction and movement.
- Contribution will vary depending on the duration, intensity and availability of fuels.
18
Q
Creatine Phosphate
A
- chemical fuel with a high energy phosphate bond for the rapid release if energy
- limited storage in the muscle
- only used by ATP-PC system
- Dominant fuel in maximal activities of durations less than 10 seconds.
19
Q
Examples of activities that use PC
A
Long jump and weight lifting
20
Q
Creatine Phosphate yield and capacity
A
- 10 seconds of PC stored in the muscle
- very low yield and capacity
- single bond splits very rapidly and can rebuild ATP at the most rapid rate
21
Q
Glycogen
A
Used via aerobic and anaerobic glycolysis systems.
- more complex fuel and rebuilds ATP at a slower rate than PC.
- 90 minutes stored in the muscles and liver
22
Q
Anaerobic glycolysis
A
Incomplete breakdown of glycogen aerobically (without oxygen)
Yield = 2 at a rapid rate
23
Q
Aerobic glycolysis
A
Complete breakdown of glycogen aerobically.
Yield = 36 at a slower rate
24
Q
Triglycerides
A
- aerobic system
- much more complex fuel (many bonds)
- ATP is rebuilt at a very slow rate
- high yield
- Dominant at low intensities, periods of passive recovery and when glycogen is depleted.
25
As athletes move from rest to submaximal intensity
- fats will decrease their contribution
- CHO will increase their contribution enabling ATP to be used at a faster rate as less oxygen required.
26
The effect of aerobic training on fats and carbohydrate usage
Increased ability to oxidise fats, shifts crossover to the right.
Process called glycogen sparing by using fats as preferred fuel source.
27
The ATP-PC System
- least complicated energy system
- Rebuild ATP at the most rapid rate without oxygen due to simple chemical pathway
- Lowest yield
- Produces energy by breaking down CP
- Finite, limited to the amount of energy stored.
28
Advantages of the ATP-CP system
- rebuilds ATP at the most rapid rate (very simple chemical pathway)
- enables athletes to work at maximal intensities (95%+ HRM)
29
How does the ATP-PC system resynthesise ATP?
- uses chemical fuel CP, a simple fuel with only one bond.
- PC splits and releases the energy to rebuild the ATP molecule at a very rapid rate.
30
By-Products of the ATP-PC system
Creatine + Pi
31
Disadvantages of the ATP-PC system
- has a very low capacity (yield 1 ATP molecule)
- Fuel CP depletes in 10 seconds of maximal intensity work.
32
ATP - PC Capacity
Finite, fuel CP depletes in 10 seconds of maximal intensity.
33
ATP- PC sporting examples
- long jump
- weight lifting
- tackle
34
ATP Capacity
Depletes after 2 seconds
35
Recovery required for the ATP-PC system
- passive recovery is the most effective strategy
- restores PC at the most rapid rate using on 35% HRM
- Low intense exercise such as walking/standing
- enables the athlete to recover faster
36
Muscular Hypertrophy
- anaerobic training results in greater PC stored in the muscle as skeletal muscles get bigger
- results in a greater capacity of ATP-PC system
- maintain maximal intensities for a longer period of time
- decrease contribution of anaerobic system
37
ATP - PC Fatigue mechanism
CP depletion
38
Rates of PC replenishment
30 seconds = 70%
60 seconds = 87%
3 minutes = 98%
39
Training the ATP-PC System
short interval training
consider:
- duration
- rest (1:5 rest ratio)
- intensity (95% HRM0
40
Impact of insufficient recovery on the ATP-PC system
- PC not restored to maximal capacity
- stores deplete faster
- increased reliance on the anaerobic glycolysis system
- decrease intensity
41
Anaerobic Glycolysis
- rebuilds ATP rapidly when high intensities are required, but CP is depleted
42
Anaerobic Glycolysis sporting examples
- 400m sprint
- repeated sprint activities
- 100m swim
43
Anaerobic Glycolysis chemical pathway
- Glycogen
- Glucose
----- ADP+PI - ATP
- Pyruvic Acid (insufficient O2)
- Lactic Acid = lactate + H ions
44
Anaerobic glycolysis energy production
- produces energy by partially breaking down glucose anaerobically
- energy produced at a fast rate due to simple anaerobic chemical reactions
- more complex chemical pathway that takes longer to break down
- slower than ATP-PC, decreasing intensity
45
Anaerobic Glycolysis HRM
85-95%
46
Anaerobic Glycolysis Fatiguing mechanism
Fatiguing metabolites (H+) produced, causing the athlete to fatigue and slow down.
47
Buffering/Tolerating Lactate
Anaerobic training, develops ability to resynthesise ATP faster.
- achieve and sustain higher intensities (greater speed, power and force) for longer
- athlete develops ability to buffer and tolerate accumulation of lactate and H+ ions
48
Lactate
Non fatiguing
Resynthesized into glycogen
49
Passive Recovery
- Involves activity below 35% HRM
eg. Standing/walking
- Builds PC more quickly
- Not suitable for increased contribution from anaerobic glycolysis system as blood will pool in muscles and veins (venous pooling)
50
Active Recovery
- 35-55% HRM approx. 5-10 mins
- maintain elevated heart rate and increase blood flow to muscles
- prevents venous pooling, removes fatiguing metabolites more quickly
- return to pre-excersise state faster
51
Why does the anaerobic glycolysis system have a finite capacity?
- incomplete breakdown of glycogen
- increased accumulation of hydrogen ions
- increased muscle acidity
- decreased enzyme function
- decrease in intensity and slow down or stop.
52
Active recovery and the skeletal pump
- normal muscle size promotes venous return to the heart against gravity
- maintain elevated heart rate activating skeletal pump
- decreases venous pooling by assisting return
- removes hydrogen ions faster
- Return to pre-exercise rate quicker.
53
Yield of Anaerobic Glycolysis system
2 - ATP
Lasts for 60 seconds
54
When does anaerobic glycolysis increase contribution?
- maximal effort required but PC stores depleted.
55
The Aerobic energy system
- most complex
- rebuilds ATP at a slower rate
- highest yield
- rebuilds ATP with oxygen (removes H+ ions)
- uses interplay of 3 fuels (glycogen, proteins and triglycerides))
- infinite capacity
- maximal intensity not achieved
56
Aerobic energy system examples
- anything over a long duration
- marathon
- tour de france
- Triathlon
56
Aerobic system HRM
65-86%
56
By products of the Aerobic energy system
H2O, C02, Heat
57
Why does the Aerobic energy system have an infinite capacity?
By products are non-fatiguing
58
Aerobic system fuel contribution at rest
2/3 fat and 1/3 CHO
59
Aerobic system and intensity of excersise
lower intensities triglycerides majority of fuel
As intensities increase, ATP needs to be rebuilt at a faster rate and glycogen will become the major fuel contributing.
60
What is the role of protein in energy production?
- extremely low contribution to ATP resynthesis
- only be used after 4 hours of continuous exercise when glycogen and triglyceride stores deplete.
Required for growth and repair of muscle tissue.
61
Aerobic system fatigue mechanism
Glycogen depletion
Elevated body temperature = more blood to skin for cooling, less blood to muscles resulting in fatigue and dehydration.
62
Impacts of depleting glycogen stores
- Increased reliance on triglycerides as a fuel
- fuel is more complex and requires more O2 to breakdown
- athlete will decrease intensity and speed, decreasing performance.
63
Benefits of CHO loading
10-15 grams CHO/per kilo body weight
- The athlete can store more glycogen (150%)
- delay use of triglycerides as a fuel
- glycogen preferred use for longer
- enables athlete to work at optimal intensities for longer.
64
Training methods for aerobic energy system
improve ability to take up, transfer and deliver oxygen to the muscles.
- continuous
- fartlek
- long interval
- circuit
- HIIT
64
Energy system Interplay checklist
1. State all three energy systems contribute towards the total energy demand
2. Determine if the activity is continuous or intermittent.
3. Justify when the ATP-PC system has a high contribution
4. Justify when the anaerobic glycolysis system has a high contribution
5. Aerobic system dominant during recovery periods and submaximal intensity as demand for ATP is low
64
How much fluid should be consumed post exercise?
1.5 Litres per every kilogram lost.
64
How do Carbohydrates travel in the blood?
Glucose
65
Name and describe Carbohydrate Substrate
Glycogen that is stored in the muscles and liver.
66
How much Carbohydrates should be consumed daily?
55-65%
67
How do Fats travel in the blood?
Free Fatty Acids
68
Name and describe the Fat Substrate
Triglycerides stored in the muscles.
69
What are Proteins?
- Used for muscle growth and repair
- Minimal contribution to energy production during exercise
70
How are proteins stored?
Travel in the blood as amino acids and stored in muscle as amino acids.
71
How much Protein should be consumed daily?
15% of daily diet
72
Examples of protein
- meat
- fish
- legumes
- grains
73
Oxygen cost of Protein
8.0 L/mol
74
High Gi Foods
Release glucose into bloodstream rapidly, increasing glucose and insulin levels
75
When should High Gi Foods be consumed?
- post exercise
- speeds up recovery as glucose rapidly transported to the muscle
- restores depleted muscle and liver glycogen
76
How much High Gi Food should be consumed post exercise?
50 grams within 15 minutes.
77
Low Gi Foods
Release glucose slowly into the bloodstream to help stabilise blood glucose during exercise.
78
When should low Gi Foods be consumed?
- pre-exercise
- stabilises blood sugar during exercise
- Used to CHO load prior endurance events to maximise muscle glycogen stores.
79
By products of ATP breakdown
ADP and Pi (inorganic phosphate)
80
How much lactate is in the blood at rest?
1 mmol/L
81
What happens to lactate levels as exercise begins?
Levels of lactate and hydrogen ions increase
When lactate cannot be broken down it diffuses into bloodstream
82
Lactate inflection point
Reflects balance between lactate entry and removal from blood.
Final exercise intensity/oxygen uptake VO2 value where blood lactate concentration relatively stable during incremental test
Maximal intensity where blood lactate at a steady state.
83
Intensities prior to LIP
lactate removal exceeds entry
84
Intensities beyond LIP
Lactate entry exceeds removal
- blood lactic acid and H+ concentration increases and fatigue occurs
85
The greater the intensity above LIP
- more rapid the fatigue
- greater contribution to anaerobic glycolysis
86
LIP data use
predicts speed/power sustained over prolonged period
- distinguishes performance of elite middle and long distance athletes better than VO2 max
87
Why does the lactate inflection point provide more useful data?
Highlights individuals who can maintain a higher aerobic energy output for longer duration.
88
Phosphocreatine recovery is delayed by
Low oxygen supply and low pH levels
89
Why does the anaerobic glycolysis system have no relevance to LIP?
- high intensity and duration
- no opportunity for oxygen to be delivered to muscles to produce aerobic energy
90
Why is LIP relevant to aerobic events
Athletes must be able to oxidise the metabolic waste produced to ensure it does not accumulate to levels that would cause them to slow down.
91
What is lactate tolerance?
The ability to sustain high intensities despite the production and accumulation of fatiguing H+ ions.
