2. Chapter 5 Foods, fuels and energy systems VCE Physical Education - Unit 3 Text Sources 1.Nelson Physical Education VCE Units 3&4: 5 th Edition – Malpeli, Horton, Davey and Telford 2010. 2. Live It Up 2: 2 nd Edition – Smyth, Brown, Judge, McCallum and Pritchard 2006.

3. Glossary Words Interplay Glycolysis Aerobic Anaerobic Carbohydrate loading Glycamic index (GI) Hypoglycaemia Mitochondria Glycogen sparing Lactate inflection point (LIP) Onset of anaerobic blood lactate (OBLA) VCE Physical Education - Unit 3

4. Foods, fuels and energy systems

5. VCE Physical Education - Unit 3  The food is broken down into soluble chemicals (e.g. glucose) by digestion in the gut.  The soluble chemicals pass through the gut wall into the blood.  The blood carries the soluble food chemicals to all of the body’s cells, where they will be used for: EnergyGrowthRepair Food is the source of energy for the human body and it also provides nutrients for growth and repair. When food is eaten, this is what happens… Food for Exercise

6. Food Fuels for Energy 1. Carbohydrates (CHO) – Preferred source of fuel during exercise (Glycogen) 2. Fat – Concentrated fuel used during rest and prolonged sub-maximal exercise. 3. Protein – Used for growth and repair (Negligible use during exercise) See fig 5.2 p.118 VCE Physical Education - Unit 3 p.87

7. Carbohydrate Contributions Intake of Carbohydrates depends on the intensity and duration of exercise. Normal contribution to diet is 55-60% CHO Carbohydrate loading (80% CHO intake) is used to endurance activities. Carbohydrate rich diet; Increases glycogen stores Glycogen is used in rebuilding ATP CHO preferred fuel over fats during exercise due to requiring less oxygen to release energy. Excess CHO is converted to adipose tissue (Fat). VCE Physical Education - Unit 3

8. Here some of the glucose is stored as glycogen and used to maintain blood sugar levels. Glucose is stored here as glycogen and is used when the body is working harder. Glucose diffuses easily into the cells and is used to meet their energy demands. Skeletal Muscle LiverBody Cells

9. Fat Contributions Storage of fats Adipose tissue Triglycerides (Broken down into free fatty acids) Aerobic metabolism of fat is; Slow Requires more oxygen Adds stress to the oxygen transport system ATP yield is much higher from fat (460 molecules) in comparison to glucose (36). At rest 50% of energy supplied by fats Oxygen demand is easily met to burn fats Benefits of fat Large energy store Transport medium for fat soluble vitamins Negative aspects of fat Adverse health effects Obesity, heart disease etc. VCE Physical Education - Unit 3

11. Protein Contributions Role of protein (Amino acids) in the body; Growth and repair Speed up reactions in the body (Enzymes) Produces hormones and antibodies Protein and exercise 1. Not used as a fuel, therefore low priority. 2. Only used in extreme circumstances 3. Normal diet contains enough protein (15%). Excess protein can lead to; Less intake of CHO Increase in fat intake from animal products Increase in fluid waste VCE Physical Education - Unit 3

12. Prolonged Endurance Events During prolonged endurance events such as marathon running and triathlons; Body uses a combination of CHO and fats. Trained athletes are able to ‘spare’ glycogen and use free fatty acids. Fats cannot be used alone as a fuel (poor solubility in the blood). ‘Hitting the wall’ occurs when glycogen stores are depleted. This is called ‘hypoglycaemia’ VCE Physical Education - Unit 3

13. Glycemic Index (GI) Glycemic index; Rating of CHO effect on blood glucose Quick breakdown with immediate effect on blood glucose levels are labelled high GI Slow breakdown are labelled low GI Before exercise you should eat; Food that maintains blood glucose levels ie.low GI food Avoid high GI food prior to exercise. High GI cause an insulin surge, effecting the performance of an athlete VCE Physical Education - Unit 3

16. Using student netbook- go to www.heartfoundation.org.auwww.heartfoundation.org.au Click on Healthy eating Click on Food and nutrients facts Students are to write down the 5 tips for healthy eating Students are then to use the website to answer Think things through Page 123 Nelson VCE Physical Education - Unit 3

18. Food Fuels in the Body and Recommended Dietary Intake Food FuelStored As Site(s)The proportions of essential nutrients contained in a balanced diet Example foods CarbohydratesHigh GI: Med GI: Low GI: Fat Protein VCE Physical Education - Unit 3

20. HOMEWORK ACTIVITY Complete Thinking Things Through pg 117 VCE Physical Education - Unit 3

21. QUIZ Complete quiz filling in table on food fuels VCE Physical Education - Unit 3

23. Adenosine Triphosphate (ATP) Our mechanical energy required for muscular contractions, require the chemical breakdown of the ATP molecule (Forms ADP). Our ATP stores are very limited, therefore it must continually be rebuilt. Nutrients assist in rejoining the split molecule VCE Physical Education - Unit 3

25. Test Your Knowledge 1. Carbohydrates are the most important nutrient in energy production. Name two foods rich in carbohydrates? 2. When comparing glycogen and fats, which requires more oxygen to produce the same amount of ATP? 3. Describe the intensity of a physical activity where fats are the predominant energy source. Give one example? 4. Give one reason why fats should not be included in a meal just prior to an extended endurance event such as a triathlon. 5. Kaila McKnight is Australia’s leading female middle distance runner with a personal best time of 4:10:01 for 1500m event. a) What is the predominant energy system used to supply ATP to the muscles for this event? b) Identify one by-product of the above energy system c) What is the predominant food fuel used to provide the ATP for this event? VCE Physical Education - Unit 3

27. The Three Energy Systems The systems used to resynthesis of ATP depend on a number of factors including; Duration Intensity If oxygen is present Availability and restoration of chemical/food fuels Systems and their names 1. ATP-PC 2. Anaerobic Glycolysis (Lactic Acid (LA)) 3. Aerobic The three energy systems do not function independently or one at a time, but work together via the process of interplay to supply energy and rebuild ATP. VCE Physical Education - Unit 3

28. Foods, fuels and energy systems

29. The ATP-PC System pg 125-6 Quickest system Breaks down phosphocreatine (PC) to form ATP anaerobically. However, PC stores require time to replenish. Dominant system for the first 10 seconds of high intensity exercise Used in fast, powerful movements. How does the system work? PC releases a free phosphate PC = P + C ADP + P = ATP VCE Physical Education - Unit 3

30. Body has a larger storage of PC compared to ATP PC stores can be replenished through aerobic recovery/passive recovery. Passive recovery for maximum ATP resynthesis, also increase removal of H+ Once PC stores are depleted, the body must use glycogen through the anaerobic pathway. Anaerobically trained athletes can resynthesise ATP faster As resynthesis decreases, intensity must decrease VCE Physical Education - Unit 3

32. The ATP/PC system during the interplay of energy systems Handout ‘Phosphate Creatine’ Read as a class and explain the graph VCE Physical Education - Unit 3

33. Using the e-learning disc. Show students ‘Sports predominantly powered by the ATP/PC system and also the 30 second video clip on ‘Carl Lewis’ competing in long jump. Read summary as a class page 126 Nelson text ‘Summary of the ATP-PC energy system’ VCE Physical Education - Unit 3

34. Foods, fuels and energy systems

35. Anaerobic Glycolysis System The anaerobic glycolysis system; Activated at the start of intense exercise More complex reactions than the ATP-PC system Peak power until it fatigues (2-3 minutes) Predominant energy supplier in events 85% max HR eg. 200m sprint. VCE Physical Education - Unit 3

36. How the system works; Glycogen is broken down in the absence of oxygen (Anaerobic glycolysis) This produces a fatigue causing by product called lactic acid. Lactic acid makes the muscle pH decrease (More acidic as more H+), reducing ATP resynthesis. The lactic acid system; Provides twice as much energy for ATP resynthesis than the ATP-PC system. Experiences problems at the anaerobic threshold. VCE Physical Education - Unit 3

37. Glucose is transported to the muscles of the body via the blood. How Anaerobic Respiration Happens Glucose passes into the muscles cells and is used to produce energy for muscular contractions. Anaerobic respiration produces lactic acid as a waste product. Facts about Anaerobic Respiration  During anaerobic respiration, your muscles are not supplied with enough oxygen.  The lactic acid builds up due to the shortage of oxygen. This is known as an oxygen debt, which needs to be paid back once exercising has finished.  The lactic acid build-up will soon make your muscles feel tired and painful, so exercising anaerobically can only be carried out for short periods of time. 123

38. VCE Physical Education - Unit 3 Anaerobic Respiration is how sprinters produce the energy that is used in short periods of ‘all out effort’ - high intensity. Glucose produces… Lactic acid quickly builds up & makes the muscles feel tired & painful. ‘All out effort’ cannot last for very long! The rest is converted into heat to warm the body. Oxygen cannot reach the muscles fast enough, so anaerobic respiration is used. Some is used for muscle contractions, creating movement.

39. VCE Physical Education - Unit 3

40. Read page 127 ‘Summary of the Lactic acid (LA) energy system’ Handout ‘How Anaerobic Glycolysis works’ Read as a class and explain graph Students are to answer the following question in their workbooks List 4 sports that are predominantly powered by anaerobic glycolysis? Make sure you include the value of the sport for example 200m sprint. Answer: 200m sprint. 100m swim, 500m kayak and consecutive sprints in intermittent sports such as netball, football, basketball, squash, hockey and water polo VCE Physical Education - Unit 3

41. ANAEROBIC METABOLIMS / PATHWAY ATP-PCANAEROBIC GLYCOLYSIS Fuel Source Fuel Location Dominant ATP Rate ATP Amount VCE Physical Education - Unit 3

42. ANAEROBIC METABOLIMS / PATHWAY ATP-PCANAEROBIC GLYCOLYSIS Fuel SourceATP-PCGlycogen/Glucose Fuel LocationSkeletal Muscle Dominant0-6sec6-60sec ATP RateHigh (3.6 mM/Min)Moderate (1.6mM/min) ATP AmountLow (1 ATP/PC)Moderate (2/3 ATP per mole glucose) VCE Physical Education - Unit 3

43. Complete “Energy System During a Maximum Sprint” Lab pg 131-2 VCE Physical Education - Unit 3

44. Foods, fuels and energy systems

45. The Aerobic System The aerobic system Slowest contributor to ATP resynthesis However, produces much more energy than the anaerobic systems Becomes major contributor once the anaerobic glycolysis decreases. Major contributor in prolonged exercise eg. Endurance events. Aerobic system does contribute in maximal intensity exercise (Eg. Between 55-65% in 800m) See table 5.4 p.129 VCE Physical Education - Unit 3

46. How the system works; 1. CHOs and Tryglycerides (FFA + glycerol) broken down to release energy. This produces pyruvic acid. 2. Pyruvic acid is further broken down producing carbon dioxide (Kreb’s cycle) 3. Further breakdown via the electron transport chain. It requires hydrogen ions and oxygen, producing water and heat. VCE Physical Education - Unit 3

49. Facts about Aerobic Respiration How Aerobic Respiration Happens… Glucose and oxygen are carried by the haemoglobin in the red blood cells. Glucose and oxygen pass into all the muscle cells of the body and is used to help produce energy for muscular contractions. Aerobic respiration produces carbon dioxide & water as waste products.  During aerobic respiration, the heart and lungs supply the muscles with plenty of oxygen.  The carbon dioxide is breathed out via the lungs, while the water is lost as sweat, urine or in the air we breathe out as water vapour.  As long as the muscles are supplied with enough oxygen, exercising aerobically can be carried out for a long period of time. 123

50. VCE Physical Education - Unit 3 Aerobic respiration is how marathon runners produce the energy that is used in long periods of less intensive effort. Glucose and oxygen produce… Carbon dioxide, which is carried away by the blood & excreted through the lungs. Water, which is carried away by the blood and excreted through the lungs, sweat and urine. Some is used for muscle contractions, creating movement. The rest is converted into heat to warm the body.

51. VCE Physical Education - Unit 3 Energy and Types of Physical Activities Each physical activity or sport you undertake requires a different energy system… Track Events and their use of Aerobic Respiration Basketball players use both systems  Some use mainly aerobic respiration.  Others use mainly anaerobic respiration.  Most use a combination of the two. Event Percentage of Aerobic Respiration Less than 1%100 m 10%200 m 20%400 m 50%800 m 60%1,500 m 83%5,000 m 95%10,000 m 100%Marathon

52. Students Are to copy Table 5.4 page 129 Nelson Text and answer the following question into their workbooks By comparing anaerobic and aerobic energy what is occurring at approximately 1 minute of maximal- intensity exercise? Answer: the energy being released is almost equal by the anaerobic and aerobic systems. When are the two systems at the 50-50 mark? Answer: at around the 75 second mark VCE Physical Education - Unit 3

53. As a class read ‘ Summary of the aerobic energy system’ page 129-130 As a class read the ‘real world focus’ on ‘Michael Johnson’ page 130 Nelson text Discuss After the 200m mark, the speed of running decreases, even though PC isn’t totally depleted and lactate concentration is not maxed. Students are to complete ‘Think things through’ page 131 Nelson text VCE Physical Education - Unit 3

54. COMPARING THE THREE SYSTEMS Give handout summarising each system Complete lab activity pg 132-3 VCE Physical Education - Unit 3

55. Thinking Things Through pg 138-9 Thinking Things Through pg 141 VCE Physical Education - Unit 3

56. Food Fuels at Rest vs Exercise Rest (Aerobic) Fat and glucose are the preferred fuels During Exercise 1. Short duration / high intensity – Anaerobic systems used using carbohydrates. 2. Long duration / low intensity – Aerobic system using carbohydrates. However, fats are used once glycogen stores are depleted. VCE Physical Education - Unit 3

58. Foods, fuels and energy systems

59. Energy Demands - Intensity Low intensity ATP requirements are met aerobically using the aerobic system. High Intensity Explosive movements require instant supply of ATP which can’t be met aerobically, therefore the ATP-PC and anaerobic glycolysis systems need to be used anaerobically. VCE Physical Education - Unit 3 Aerobic Anaerobic

60. Interplay Between Energy Systems All energy systems start at the same point, but each system will peak at different times. All activities use some energy from all three systems. The energy systems overlap – they never work independently. It it’s the relative contribution of each system that varies. VCE Physical Education - Unit 3

61. Duration and Intensity VCE Physical Education - Unit 3 Duration of eventIntensity of eventPrimary energy system(s) 0-6 secondsvery intenseATP-PC 6-30 secondsintenseATP-PC and Lactic Acid 30 sec. - 2 minutesheavyLactic Acid 2-3 minutesmoderateLactic Acid and Aerobic > 3 minuteslightAerobic

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64. High Intensity Competition VCE Physical Education - Unit 3