ENERGY CONCEPTS 1)CHEMICAL ENERGY: Plants convert SUNLIGHT into energy which is stored within the BONDS of chemical COMPOUNDS or MOLECULES. This is then passed to HUMANS in the form of FOOD. It is stored as CHO, PROTEIN or FATS. We then further store this energy in a HIGH ENERGY compound called ADENOSINE TRI-PHOSPHATE (ATP). ATP can be immediately used as energy by the body. Energy found between the bonds of ATP is called.... 2)POTENTIAL ENERGY: This is when energy is ready to use, for example when muscles CONTRACT. This energy is called … 3)KINETIC ENERGY: which is energy in the form of MOVEMENT. ENERGY is the ability to perform WORK or put MASS into MOTION. In human terms it means contracting muscles for physical activity. It is measured in JOULES (J) which is equivalent to 1 NEWTON force or 1Kg acting over a distance of 1 metre. It can also be measured in CALORIES and this is equivalent to 4.18 Joules. WORK is when a FORCE is applied to a body to move it over a distance. WORK = FORCE (N) X DISTANCE MOVED (M) measured in Joules POWER is the RATE at which WORK can be done. It is work divide by time. POWER = WORK / TIME or (FORCE (N) x DISTANCE (M)) / TIME (secs) The UNITS are WATTS (W). Force X Distance = PURE STRENGTH

ADENOSINE TRI PHOSPHATE (ATP) ATP is made up of a complex element called ADENOSINE and three simple elements called PHOSPHATEs (P). These elements are held together by BONDS which are HIGH ENERGY bonds. An ENZYME called ATPase breaks the bonds between 2 of the Phosphates. When it does this it releases ENERGY which is used for muscular CONTRACTIONS. This is an EXOTHERMIC reaction because it RELEASES ENERGY as it progresses. The COMPOUND which is left is called ADENOSINE DI PHOSPHATE (ADP). If there is no ATP present then energy for work is not possible. The body only has a LIMITED CAPACITY to store ATP. It can only last for 2 to 3 SECONDS of work. After this time the body has to find a way of RESYNTHESISING ADP back into ATP again. It has lost a Phosphate. ADP must find another to REBUILD it an become reusable. This is an ENDOTHERMIC REACTION because energy is REQUIRED from somewhere to progress. The body has 3 ENERGY SYSTEMS with which to re-synthesise ADP to ATP. 1)The ATP / PC SYSTEM 2)The LACTIC ACID SYSTEM 3)The AEROBIC SYSTEM Each system uses energy from one reaction to use in another reaction. This is called a COUPLED REACTION

ENERGY SYSTEMS The 3 Energy Systems that re-synthesise ATP from ADP are the 1) ATP/PC system 2) Lactic Acid System 3) Aerobic Energy System When ATP levels fall and ADP levels rise an ENZYME called CREATINE KINASE is released and this breaks the PC bond in an EXOTHERMIC reaction. This energy is used to re-synthesise ATP from ADP in an ENDOTHERMIC reaction 1.The ATP / PC system can work ANAEROBICALLY as well as AEROBICALLY but it does NOT require 02. It takes place in the SARCOPLASM of the cell. However it can only supply enough PC to re-synthesise ADP to ATP for 3 to 10 seconds during MAXIMAL intensity. In recovery, Creatine and Phosphate (Pi) are re-synthesised back to PC TRAINING ADAPTATIONS: Anaerobic Training overloads the ATP / PC system and increases the muscle’s ATP and PC stores which delays the THRESHOLD between using this system and the Lactic Acid System by 2 secs ADVANTAGES: No 02, Quickly Available, Quick Reaction, Explosive, Powerful, No Fatiguing By Products, PC re-synthesised quickly DISADVANTAGES: Stores are small, 1PC re-synthesises 1ATP, Only energy for 8 – 10 secs

ENERGY SYSTEMS 2) The LACTIC ACID SYSTEM: This system uses GLYCOGEN to re-synthesise ADP back to ATP. The energy released through breaking down glucose is used to do this. This is also a COUPLED and ENDOTHERMIC reaction. Glucose is CHO in the body and when it is stored it is called GLYCOGEN. The decrease in PC stores activates the ENZYME GLYCOGEN PHOSPHORYLASE which breaks down the glycogen into glucose. It is then further broken down into PYRUVIC ACID in a process called GLYCOLYSIS. The process takes place in the SARCOPLASM, does not require 02 and is called ANAEROBIC GLYCOLYSIS. This process releases 2 ATP from one glucose molecule During Glycolysis the ENZYME PHOSPHOFRUKTIKINASE (PFK) causes the breakdown into Pyruvic Acid but without 02 this breaks down further into LACTIC ACID by the ENZYME LACTATE DEHYDROGENASE (LDH). This process re-synthesises energy for 2 – 3 minutes of high intensity exercise but if activity is MAXIMAL it will only last 30 seconds ADVANTAGES: Relatively QUICK, no 02 required, Glycogen readily available DISADVANTAGES: OBLA, Inhibition of ENZYMES due to lower Ph, increased FATIGUE, stimulates PAIN receptors TRAINING ADAPTATIONS: Overloading this system will increase LACTATE BUFFER and delay OBLA

ENERGY SYSTEMS 3)The AEROBIC ENERGY SYSTEM: This has 3 stages to re-synthesise ATP. All 3 systems require 02 to break down 1 molecule of Glucose STAGE 1: AEROBIC GLYCOLYSIS: This is the same process as anaerobic glycolysis but instead the presence of 02 INHIBITS the accumulation of LACTIC ACID. The 02 uses PYRUVIC ACID and this combines with ‘CoENZYME A’ to become ‘ACETYL CoENZYME A’. This takes place in the SARCOPLASM. STAGE 2: KREB’s CYCLE: The ‘ACETYL CoENZYME A’ now combines with OXALOACETIC ACID to form CITRIC ACID in the MITOCHONDRIA. This is then broken down to produce 4 EVENTS 1) C02 is produced and removed 2) HYDROGEN ATOMS are removed (Oxidation) 3) OXALOACETIC ACID is regenerated which is used again 4) Energy is produced to re-synthesise 2 ATP STAGE 3: The ELECTRON TRANSPORT CHAIN (ETC): HYDROGEN ATOMS released in Stage 2 combines with CoENZYMES NAD and FAD to form NADH and FADH. These are carried down the ETC where HYDROGEN is split into HYDROGEN IONS (H+) and HYDROGEN ELECTRONS (e-). This takes place in the MITOCHONDRIA and 3 EVENTS follow 1) e- split from the atom and pass down the ETC 2) This provides ENERGY to synthesise 34 ATP 3) H+ combines with 02 to form water (H20)

ENERGY SYSTEMS ADAVANTAGES: large GLYCOGEN & FFA stores, 02 supply Large synthesis, High DURATION (3 mins to 1 hr), No fatuiging BY PRODUCTS (C02/H20) DISADVANTAGES: Slower Resynthesis, Requires 15% more 02 supply for FFAs, COMPLEX reactions, Initial DELAY of synthesis at start of activity, Limited ENERGY during high intensity activity FATS (TRIGLYCERIDES) are broken down by ENZYME LIPASE into FFAs which are the broken down into ACETYL CoA. This is where it enters the KREB Cycle. They can produce more Acetyl CoA than Glucose but require 15% more 02. TRAINING increases Glycogen in muscle and liver, increases mobilisation of Enzymes and uses FFAs early = Aerobic Threshold increased TOTAL ENERGY YIELD from the Aerobic System is 38 ATP from one molecule of Glucose 2 ATP from Anaerobic Glycolysis 2 ATP from the Kreb’s Cycle 34 ATP from the ETC EQUATION for AEROBIC RESPIRATION: C6 H12 O6 + 6O2 = 6C H20 + ENERGY (for 38 ATP re-synthesis) Glucose is completely broken down in the Aerobic system by 02 into C02 and H20

ENERGY CONTINUUM The Energy Continuum is a GRAPHICAL display of how the energy systems INTERACT together to provide energy for the re-synthesis of ATP. It highlights the PERCENTAGE of each of these 3 systems relating to both the DURATION and the INTENSITY of the activity. Each sport/physical activity requires di8fferent percentages from each system. They RARELY work in ISOLATION. Some activities are mainly AEROBIC whilst others are ANAEROBIC. Most use a COMBINATION of all 3 Draw the following graph to represent how the Energy Systems Interact. X Axis = Time in minutes from 0 to 360 seconds and the Y Axis = Capacity of Energy System in % from 0 to 100%. Plot the following data for 3 lines 1) ATP / PC System (12, 98) (16, 50) (22,5) 2) Lactic Acid System (Anaerobic Glycolysis) (2, 1) (15, 60) (20, 95) (45, 98) (120, 93) (180, 50) (240, 35) (300, 25) 3) Aerobic Energy System (10, 10) (20, 25) (120, 40) (300, 70) (360, 98) Highlight the points at which the PREDOMINAT energy system changes

THE 6 FACTORS THAT AFFECT THE TYPE OF ENERGY SYSTEM USED 1)INTENSITY and DURATION of the exercise: when the intensity is ANAEROBIC HIGH INTENSITY SHORT duration the system will be ATP/PC When intensity is LOW and duration is LONG the system will be AEROBIC. When intensity reaches a point that the aerobic system cannot be used it uses the LACTIC ACID system but this produces LACTIC ACID. The LACTATE THRESHOLD crossed when blood lactate is above resting levels. When blood lactate reaches 4mmol/L and above then OBLA has been reached. Fatigue will occur 2)ENERGY SYSTEM THRESHOLDS: a threshold is the POINT at which an energy system is taken over by another. ATP/PC system is 2-10seconds. ATP / PC changes to Lactic Acid System at 10 – 90 seconds. Lactic Acid to Aerobic System changes at 90 seconds to 3 minutes. After this it is the Aerobic System unless INTENSITY is high. 3)02 AVAILABILITY: As long as 02 supply is there the Aerobic System will re- synthesise ATP. If there is INSUFFICIENT 02 the LACTIC ACID system will be used. This is dependent on Respiratory and CV EFFICIENCY

THE 6 FACTORS THAT AFFECT THE TYPE OF ENERGY SYSTEM USED 4) FUEL AVAILABILITY: PC will be used for SHORT, HIGH intensity activity. Duration cannot be sustained when PC stores DEPLETE and intensity remain HIGH. PACING can conserve PC stores and RECOVERY periods can re- synthesise them. GLYCOGEN is the MAJOR fuel for the first 20 minutes of activity. It is readily available in the muscles and requires 15% less 02 than FFAs. It takes 2-3 minutes to use this though as sufficient 02 has not had time. Between 20 – 45 minutes FFAs will be broken down as well but only if intensity is LOW because of the need for 15% more 02. High LIVER GLYCOGEN levels will allow the athlete to maintain a higher intensity After 2 HOURS glycogen is DEPLETED and FFAs must be used. Unless athletes reduce intensity to allow 02 supply they may HIT THE WALL. 5)ENZYME ACTIVATION LEVELS: Reactions cannot take place without them. CREATINE KINASE is released when ADP increases and ATP decreases. This activates the PC system. PFK is released when PC decreases and this activates the Lactic Acid system. PFK is also released when ADRENALIN increases and INSULIN decreases, activating the AEROBIC system 6)FITNESS LEVELS: The more aerobically fit an athlete is the better 02/C02 transport which is essential to break down glycogen and FFAs. Conserving glycogen is crucial to delay OBLA and aerobic and lactate THRESHOLDS

THE RECOVERY PROCESS The Recovery process is concerned with the events AFTER exercise. It is important DURING exercise to allow performers to MAINTAIN performance and also AFTER exercise to SPEED UP their recovery. The aim is to RESTORE the body to its PRE EXERCISE STATE by removing BY PRODUCTS and by the REPLENISHMENT of FUELS. After exercise the body does not return immediately to its pre exercise state. RESPIRATION and HEART RATE remain elevated. This is known as EPOC (EXCESS POST EXERCISE 02 CONSUMPTION) or 02 Debt. It has 2 STAGES: 1)ALACTACID DEBT: (RAPID RECOVERY Stage) This restores stores of PHOSPHAGEN and the re-synthesis of ATP, PC, MYOGLOBIN and Hb. It requires approximately 3-4 Litres of 02 and takes about 3-4 minutes but 50% are restored in 30 seconds and 75% restored in 1 minute 2)LACTACID DEBT: (SLOW RECOVERY Stage) Early research thought this was responsible for the removal or re-conversion of LACTIC ACID into either PYRUVIC ACID (which can be used as fuel) GLYCOGEN or PROTEIN. Now it is thought that it supports A) METABOLIC FUNCTIONS such as HIGH TEMPERATURE, B) remaining HORMONES such as adrenalin, and C) elevated CARDIAC OUTPUT to reduce temperature. It requires 5-8 Litres of 02 and can take between 1-24 hours depending on the exercise intensity

THE RECOVERY PROCESS Increased levels of C02 formed during exercise is removed as CARBONIC ACID, CARBOAMINOHAEMOGLOBIN, or in the PLASMA. The CHEMORECEPTORS stimulate the RCC and the CCC to ensure that respiration and heart rate are ELEVATED during recovery to assist C02 removal. A major factor of MUSCLE FATIGUE is GLYCOGEN DEPLETION. Most can be REPLENISHED within hours after exercise. Complete recovery can take 2 DAYS in prolonged endurance events. FAST twitch fibres can replenish quicker. CARBOHYDRATES in recovery are crucial for this to happen Draw the following graph for Glycogen Depletion: X axis = Time of Exercise (0 to 1 hour )and Recovery (0 to 24 hours). Y axis = Muscle Glycogen % (0 to 100%) Plot the following: A) Exercise Time 0 mins = 100%, 1 hour = 30 % B) Recovery Time 4 hours = 50%, 8 hours = 60%, 12 hours = 70%, 16 hours = 77%, 20 hours = 83%, 24 hours = 90% Label the graph