Chapter Six : The 3 Energy Systems Working Together to Produce ATP Flashcards
What is the fuel that is necessary for all muscular contractions?
ATP
What are the three energy systems that produce ATP?
ATP-PC system
Anaerobic Glycolysis system
Aerobic energy system
Interplay
A situation where all 3 energy systems contribute to ATP production, with one system being the major producer at all times
What are the 3 food fuels that are used to recharge ATP?
Carbohydrates
Fats
Proteins
Carbohydrate storage
Stored as glucose in the blood
Stored as glycogen in the liver/muscles
Fat storage
Stored as free fatty acids in the blood
Stored as adipose tissue in the muscles/liver
Protein storage
Stored as amino acids in blood/muscles
ATP
Adenosine triphosphate
A chemical compound made up of adenosine and three phosphates; energy released by the breakdown of ATP enables cellular function and muscular movement
How is energy released from ATP?
The third phosphate breaks off the chain and creates ADP (adenosine diphosphate) and an inorganic phosphate
How does ATP resynthesise?
Stored Phosphate Creatine breaks down and combines with ADP to create ATP
How is glycolysis broken down?
Broken down into two pyruvic acid molecules that release ATP as energy
Sufficient O2 = aerobic glycolysis, goes into mitochondria to produce more ATP
Insufficient O2 = anaerobic glycolysis, transforms into lactate then lactic acid and H+ ions
Breakdown of food fuels at rest
33% glucose
66% fats
Breakdown of food fuels at maximal activity
100% glucose/carbs
Breakdown of food fuels at submaximal activity
70% glucose
20% fats
10% protein
Contribution of carbs to energy production
During anaerobic (high intensity, short duration) exercise carbs are the primary source once PC has been depleted During submaximal activity energy comes from glucose then fats Glucose is preferred fuel source because they take less O2 to break down into ATP
Contribution of fats to energy production
Transport of free fatty acids to muscle fibres is slow
Lots of O2 to break it down
In prolonged submaximal exercise fats begin to take over as glycogen is depleted
As fats use more oxygen it causes athletes to slow down to allow O2 to create ATP
The contribution of protein to energy production
Large amounts of O2 is required to break down protein for energy so it is not used as a fuel source unless in extreme circumstances
Forms the building blocks of tissue (growth and repair)
Important for the synthesis of hormones and antibodies
Average athlete food fuel consumption
10-15% protein
25-30% of fats
55-65% carbs
Disadvantage of overconsuming food groups
Protein - displacement of carb-rich foods, excess fat intake, nitrogen excretion (dehydration)
Fats- CVD, atherosclerosis
Glycemic index definition
An index that ranks foods on a scale of 0-100 according to how much they raise blodd sugar over a 2 hour period
GI measures
< 55 = Low GI
55-69 = Medium GI
>70 = High GI
Low GI food examples
Bread - multigrain, sourdough Cereal - muesli, oats Rice - Basmati Pasta - noodles, wheat pasta Grains - quinoa, pearl cous cous Legumes - chickpeas, kidney beans Starchy vegetables - sweet potato Fruit - Apple, banana Dairy - milk, yoghurt
High GI food examples
Icecream rice cakes Condenesed milk Cantaloupe potato Broad beans Polenta/cous cous Gnocchi white/brown rice coco pops white/wholemeal bread
Prolonged endurance events energy proudction
As the intensity of the exercise drops and the duration increases the body relies more on fats as fuel
In the early stages of a race glycogen is used first but the sooner an athlete can use fatty acids the greater glycogen they can stroe for later in the race when intensity tends to increase
The cross over concept
Is the intensity at which energy from carbohydrates predominates over energy from fats
Glycogen sparing definition
A long term adaptation that allows fats to be used more readily and earlier during performances; this results in less use of the lactic acid system and allows glycogen to be used much later in performances
ATP-PC energy system
Is anaerobic and doesn’t require O2
It uses PC to resynthesise ATP but only has 10 secs worth
Only can be replenished at complete rest og about 60 secs
>95% of max HR
Byproducts are inorganic phospates and ADP
Anaerobic glycolysis system
Anaerobic
Produces lactate/lactic acid - makes muscles acidic
It is slower than ATP-PC as it has more complex chemical reactions
Higher yield than ATP PC
85-95% of max HR
Lactate Inflection Point
The exercise intensity that lactate can be removed as fast as it is produced
The intensity where AG becomes dominant aerobic system
Onset of Blood Lactate
When lactate levels reach 4mmol/L and begin to rise rapidly, causing fatigue in the body
Aerobic Energy System
Uses O2 to completely break down glycogen and fatty acids
It rebuilds ATP at a much slower rate
Lasts for a really long time until fuels completely deplete
Oxidises the H+ ions and converts it to glycogen
Provides significant energy in maximal energy
<85% of max HR
Byproducts are CO2, H2O and heat
Steady state definition
When the intensity of the exercise can be matched by the supply of O2
What does interplay depend on?
The dominance of each system
Intensity, type and duration of exercise
O2 uptake/ O2 deficit
At the start of exercise O2 demand is more than O2 uptake
Anaerobic systems are used until the O2 uptake meets demand (60 seconds)
VO2 max definition
Is the highest intensity you can work while the aerobic system is dominant energy system while maintaining a steady state
Oxygen debt definition
The volume of O2 used during recovery from exercise that is in excess of resting O2 consumption
2 types of O2 replenishment
Fast replenishment
Slow replenishment
Fast replenishment
3-5mins
PC resynthesis
Slow replenishment
30+ minutes
Removal of lactic acid/H+
Restore core body temp
Restore heart rate, ventilation to pre exercise levels
Relationship between intensity and EPOC
The higher the intensity the higher the O2 debt
When a steady state has been established added to the AG system providing energy during high intesnity effort that extends the O2 debt
A person with aerobic training will be able to consume more O2 at the steady state, reducing the need for the AG system and reducing O2 debt
