Paper 1 - Energy Systems Flashcards
What do all fuels convert to?
ATP
Adenosine triphosphate
What is ATP?
The only thing that can create energy
Made up of 1 adenosine and 3 phosphate molecules
Explain the break down of ATP
In order to release the energy that is held in the bonds between three phosphate molecules in ATP, one of these bonds must be broken. This chemical reaction is catalysed by ATPase which splits the bond between two of the phosphate molecules to produce ADP (adenosine diphosphate), 1 phosphate molecule and energy. This is called an exothermic reaction.
Explain the re synthesis of ATP
ATP only last for approximately 2 to 3 seconds. We do not have an endless supply of ATP within the body and, therefore, it needs to be re-synthesised after it is broken down, in order to provide more energy in the future. It is resynthesised by using energy to form a bond between a phosphate molecule and ADP. The ATP that is formed will be available to fuel the next burst of high intensity exercise that an athlete performs. This is called an endothermic reaction.
What are the 3 energy systems?
The body must use one of three energy systems to produce the energy which is required to re-synthesise ATP from ADP + P.
ATP-PC (phosphocreatine) system
Glycolytic system
Aerobic system
What is the ATP-PC energy system?
Re-synthesises ATP from breakdown of phosphocreatine.
Predominate during a sudden movement
PC is high in type 2B fibres
What is the glycolytic energy system?
Re-synthesises ATP from the breakdown of glycogen.
What is the aerobic energy system?
Re-synthesises ATP from the breakdown of glycogen, glucose and free fatty acids (FFAs)
Predominate at rest
Summarise the breakdown of ATP as an equation
ATP —ATPase—> ADP + P + Energy
Summarise the ATP-PC system in the form of equations
PC —creatine kinase —> P + C + Energy (EXOTHERMIC)
(Coupled reaction)
Energy + ADP + P -> ATP (ENDOTHERMIC)
What is a coupled reaction
When the products from one reaction such as energy are then used in another reaction
What is an exothermic reaction?
A chemical reaction that releases energy as it progresses
(breakdown of ATP and breakdown of PC)
What is an endothermic reaction?
A chemical reaction that requires energy for it to progress
(Resynthesis of ATP)
Fill in the ATP-PC on the energy systems table
Bamboo paper
ATP-PC : Adaptions to training
Anaerobic training overloads system = increase in muscle stores of ATP and PC
(Examples of anaerobic training = weight training and sprinting)
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This delays threshold and increases potential duration
(e.g. 10 seconds goes to 10.5 or 11 seconds, 1 extra second is very valuable in sprinting, etc)
ATP-PC System : Advantages
Doesn’t require oxygen
PC stored in muscle cell = readily accessible and available
Simple/small compound = quick reaction/resynthesis
Automatically stimulated by decreased ATP levels
No fatiguing products
ATP-PC System : Disadvantages
Only small amount of ATP (2-3s) and PC (10s) stored in muscles and cells
1 PC resynthesis to 1 ATP = very low yield
Only provides energy for up to 10 seconds = cannot be sustained
Fill in the glycolytic system on the energy systems table
Bamboo paper
Describe the resynthesis of ATP via the glycolytic system
The lactic acid system breaks down glucose/glycogen to provide energy via coupled reactions. Anaerobic glycolysis. Glucose is provided directly from digestive carbohydrates/stored glycogen located in the liver and muscle is the decrease of PC stores activates the enzyme glycogen phosphorylase (GPP) to break down glycogen into glucose. Glucose is then broken down into pyruvate (pyruvic acid) by the enzyme phosphofructose kinase (PFK). In the absence of oxygen pyruvate is then converted to lactic acid by lactate dehydrogenase (LDH). The main limitation of the lactic acid system is due to the onset of blood lactate accumulation (OBLA). This accumulation of lactic acid decreases blood pH and therefore inhibits enzymes used in glycolysis. This causes fatigue and can be quite painful. OBLA occurs at 4mmol per litre of blood.
DRAW DIAGRAM LIKE ON BAMBOO PAPER
Glycolytic : Adaptations to training
Anaerobic training, overloads system = increase in body is tolerance (get rid/break down, lactic acid better/quicker) to lactic acid
Increases glucagon store (metabolic adaption)
Delays OBLA (due to tolerance) prolonging, lactic acid threshold (from about 1 minute - 1.5/2 minutes)
Glycolytic : Advantages
Large glycogen stores in muscles/liver = readily available as a potential energy store
Resynthesised 2 ATP = more than ATP-PC system
Fewer reactions than aerobic system = quicker supply of energy
Enzymes are activated as soon as PC levels decrease
Provides energy for high intensity activities for 10 to 180 seconds
Glycolytic : Disadvantages
Not as quick as ATP-PC system
Produces lactic acid, fatiguing product = lower pH = OBLA and enzyme inhibition = stimulation of pain receptors
Net effect = muscle fatigue/tiredness and pain
Fill in the aerobic system on the energy systems table
Bamboo paper
Describe the resynthesis of ATP via the aerobic system (1st stage)
Aerobic glycolysis:
Same as anaerobic (The lactic acid system breaks down glucose/glycogen to provide energy via coupled reactions. Anaerobic glycolysis. Glucose is provided directly from digestive carbohydrates/stored glycogen located in the liver and muscle is the decrease of PC stores activates the enzyme glycogen phosphorylase (GPP) to break down glycogen into glucose. Glucose is then broken down into pyruvate (pyruvic acid) by the enzyme phosphofructose kinase (PFK). In the absence of oxygen pyruvate is then converted to lactic acid by lactate dehydrogenase (LDH).)
However, aerobic glycolysis is in the presence of oxygen which prevents the accumulation of lactic acid. Pyruvate combines with Coenzyme A to form Acetyl CoA. This provides enough energy to re-synthesise to ATP.
DRAW DIAGRAM LIKE ON BAMBOO PAPER
Describe the resynthesis of ATP via the aerobic system (2nd stage)
Kreb’s Cycle
The Acetyl CoA from stage one combines with oxaloacetic acid and enters the Krebs cycle to form citric acid. CO2 is produced and two ATP are formed. It is an oxidative reaction because hydrogen atoms are lost and transferred to stage three. Oxaloacetic acid is regenerated and the cycle repeats.
DIAGRAM ON BAMBOO PAPER
Describe the resynthesis of ATP via the aerobic system (3rd stage)
Electron Transport Chain (ETC)
The hydrogen atoms bind with NAD and FAD (hydrogen carriers) to form NADH and FADH. These molecules are carried down the ETC which splits hydrogen into ions (H+) and electrons (H-). Hydrogen ions are oxidised and removed as H2O. (H+ combines with oxygen). splitting of H+ and H- provides sufficient energy to resynthesised 34 ATP.
Total ATP synthesise for aerobic system is 38 ATP.
DIAGRAM ON BAMBOO PAPER
Aerobic : Adaptations to training
Increases stores of muscle liver glycogen
Mobilisation of aerobic, enzymes and earlier use of FFA’s
Aerobic threshold is prolonged, and OBLA is delayed = quicker/more efficient recovery
Aerobic : Advantages
Large potential glycogen and FFA’s stores available as efficient, energy fuel
Efficient ATP resynthesis when good oxygen supply
Large ATP resynthesis (38 ATP : 1 glucose molecule)
Provides energy for low/moderate intensity, and high duration exercise
No fatiguing products (CO2 and H2O are removed easily)
Aerobic : Disadvantages
Slower rate of ATP resynthesis
Requires constant oxygen supply (15% more when breaking FFA’s down)
Complex series of reactions = slower reaction/recovery
Cannot re-synthesise ATP at start of exercise due to initial delay of O2 from the cardiovascular system
Limited energy for ATP during high intensity, short duration work
Fat as a fuel
Triglycerides (fats) are broken down by lipase into free fatty acids and glycerol
FFA’s are broken down into acetyle CoA which then enters the Krebs cycle
FFA’s produce more acetyle CoA so produce more energy than glucose
However, they require 15% more oxygen to break down
O2 Availability
Sufficient O2 means the aerobic system will provide ATP for extended periods
If O2 supply falls below demand, the glycolytic system will produce ATP anaerobically
Therefore, the efficiency of the CV and respiratory system determine the threshold for aerobic activity
Fuel Availability (metabolic adaptations)
ATP/PC
- Sufficient PC means the ATP PC system will last for 8 to 10 seconds
- PC stores can be conserved by pacing and PC replenishment during rest periods using the aerobic system
- If not sufficient PC, we move across the threshold to the glycolytic system
Glycogen
- Glycogen is the preferred energy source as it is available at the muscle and take less energy to break down than FFA’s
- FFA‘s are more efficient sources of energy, but take more O2 to break down there for at higher intensity is glycogen is the preferred source
- Running out of glycogen is termed ‘ hitting the wall’ (90-120 mins). Intensity must be reduced to utilise FFA’s
Glycogen sparing = the ability to use facts earlier in exercise, preserving glycogen for later in an event
What does the energy continuum represent?
The energy continuum shows how the systems interact to provide energy for the re-synthesis of ATP. It also highlights the dominant energy system at a given time and intensity.
What does the energy continuum diagram look like?
Bamboo Paper
What are energy system threshold points?
The point at which one energy system is taken over by another as the predominant energy system to provide energy for the resynthesis of ATP.
Thresholds in relation to the energy continuum
Table on Bamboo paper
What is OBLA in relation to energy continuum
It occurs when your body cannot process lactate quickly enough and thus you begin to tire, it lowers pH of blood, inhabiting enzyme action, stimulating, pain receptors, and causing muscle fatigue. This occurs at 4 mmol/L.
Factors affecting the energy system utilised (intensity and duration)
High intensity and short duration = ATP-PC and Glycolytic systems
Medium/low intensity and long duration = Aeorbuc system will be predominant
Factors affecting the energy system utilised (high, very high and low intensity)
Very high - duration less than 10 sec (2-10 sec)
- E.g. athletic jumps, throws, 100m sprint
- ATP-PC system predominant, contributing up to 99% of ATP resynthesis
High - duration is 10 sec - 3 min
- E.g. 400m run, 200m freestyle swim
- Glycolytic system predominant, contributing up to 60-90% of ATP resynthesis
Low - duration is more than 3 min
- E.g. marathon, triathlon
- Aerobic system predominant, contributing up to 90% of ATP resynthesis
Factors affecting the energy system utilised (intermittent exercise)
Activity where intensity alternates.
E.g. interval training (alternates between rest and work:
games with breaks in play (basketball) or changes in intensity (football)
Factors affecting the energy system utilised (fitness levels)
CV and respiratory fitness (higher VO2 max) will result in better O2 utilisation.
OBLA reached at 50-60% of VO2 max for untrained, 85-90% for trained.
Training increases fuel stores and enzyme levels which increases thresholds.
What does VO2 max mean?
Maximum amount of O2 that can be used during exercise.
Factors affecting the energy system utilised (other factors affecting energy systems used)
- recovery periods
- position of player in team games
- tactics (e.g. man to man or zonal marking)
- level of competition
- structure of game (large pitch = more aerobic (football), smaller court = more anaerobic (tennis, basketball))
What is the Recovery Process
The recovery process aims to restore the body to its pre-exercise state (key process of recovery is EPOC)
What is EPOC
Excess Post-exercise Oxygen Consumption
The amount of oxygen consumption above resting level, required to restore the body to its pre-exercise state.
Draw the diagram of recovery
Bamboo paper
What is the alactacid stage of recovery?
The fast recovery stage
- phosphogen stores replenished (as elevated respiration helps ATP and PC stores replenish).
- myoglobin is saturated with O2 (oxymyoglobin)
- requires 3-4 litres of oxygen
- 50% of PC stores are restored within 30 secs
- 2-3 minutes for full recovery = very quick/rapid
What is the lactacid recovery stage of recovery?
Slow recovery stage
It is primarily responsible for the removal of lactic acid. This is done in two ways (Convert lactic acid back to pyruvic acid and use it as a metabolic fuel, Convert lactic acid in to glycogen, glucose (gluconeogenesis/glyconeogenesis) or protein.)
Cardiac output/Minute ventilation and body temperature (speeds up processes/metabolism) remain high while this process begins. Eventually levels return to resting
Lactic acid removal relies on the ability of the CV system to neutralise/break down Lactic acid.
The process takes 1 to 24 hours depending on the intensity and duration of the exercise
Requires up to 8L of O2
Recovery : The fate of lactic acid
65% converted to CO2 and water (by being converted to pyruvic acid and being used in the aerobic system (CO2 produced in Krebs cycle / water in ETC)
20% Glycogen
10% Glucose
5% Protein
Recovery : CO2 removal
Elevated respiration and heart rate remove CO2
CO2 is carried by:
RBCs as Carbonic acid
Haemoglobin
Plasma
(At the same time myoglobin is replenished with 02)
Recovery : glycogen replenishment
Muscle and liver glycogen can deplete quickly and is major factor in muscle fatigue
The majority of glycogen can be replaced within 10 to 12 hours but can take up to 2 days
Glycogen is best replaced by eating a high carbohydrate diet in the first 2 hours
Recovery Strategies : What are the aims of training (improve speed using ATP-PC system)
Work will tend to be less than 10 seconds
The work relief ratio is a minimum of 1:3 (30 sec relief = 50% pc restoration)
Recovery Strategies : What are the aims of training (improve tolerance to lactic acid to improve speed endurance)
Work will be short in duration 10-30 seconds but relief will reduced ration 1:2
Increasing work, duration increase lactate production, overloading the lactic acid system (glycolytic system)
Recovery Strategies : What are the aims of training (improve VO2 max using aerobic system)
Work periods are longer, working just below anaerobic threshold. Ratio 1:1. This helps to avoid OBLA therefore prolong aerobic adaptations.
Recovery Strategies : Applying recovery to training sessions/competition
- Complete a warm up to reduce O2 deficit (less to ‘pay back’)
- Anaerobic work must be followed by active recovery to speed up lactic acid removal
- Aerobic exercise can be followed by a more passive recovery
- Use all opportunites in an event (breaks, time-outs, tactics) to allow ATP, PC and myoglobin O2 stores to replenish
- A mix of anaerobic and aerobic training will help delay the ATP-PC and glycogen system - Athletes will use HR monitors to measure intensity in order to maximise training using work-relief strategies
- Nutritional strategies pre, during, post
Recovery Strategies : Other methods used
Ice baths
Massage
RICE (rest, ice, compress, elevate)
All help to remove lactic acid by promoting the delivery of O2 rich blood. Also reduce the effects of DOMS.
What are the recovery strategies and predominant energy system for speed/explosive strength?
ATP-PC
Warm up
Active recovery
Work : Relief ration (1:3+)
Timeouts and substitutions
Creatine supplements
Cool down
What are the recovery strategies and predominant energy system for lactate tolerance?
Glycolytic
Warm up
Active recovery
Work : Relief ratio (1:2)
Cooling aids
Timeouts, substitutions, marking strategies, set plays
Pre/during/post-event carbohydrates
Bicarbonate (soda loading)
Cool down
What are the recovery strategies and predominant energy system for aerobic capacity?
Aerobic
Warm up
Passive recovery
Cooling aids
Work : Relief ration (1:1 or 1:0.5)
Marking and substitutions
Carbohydrate loading + during and post event meals/snacks
Cool down
