Chapt 4

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

Food Fuels Foods, Fuels and Energy systems

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

Foods High in CHO, Fats and Proteins VCE Physical Education - Unit 3

VCE Physical Education - Unit 3

Complete questions 1-4 page 87 of Nelson Physical Education VCE Units 3 & 4. Checkpoints VCE Physical Education - Unit 3

Adenosine Triphosphate (ATP) Foods, fuels and energy systems

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

Fuel use at Varying Intensities and Duration Foods, Fuels and Energy systems

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

Maximal and Sub-maximal Activity VCE Physical Education - Unit 3

Contributions of Carbohydrates, Fats and Protein to Energy Production Foods, Fuels and Energy systems

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 lactic acid systems need to be used anaerobically. VCE Physical Education - Unit 3 Aerobic Anaerobic Intensity increases

Carbohydrate Contributions Storage (Based on 80kg person) Muscle glycogen – 400g Liver glycogen – 100g Intake of Carbohydrates depends on the intensity and duration of exercise bouts. 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. Athletes need to be aware of their dietary intakes of CHO. Excess CHO is converted to fat. VCE Physical Education - Unit 3

Fat Contributions Storage of fats Adipose tissue Triglycerides (Broken down into free fatty acids) Aerobic metabolism of fat is; Slow as it requires more oxygen than CHOs. 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

Crossover Concept VCE Physical Education - Unit 3

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 Not used as a fuel, therefore low priority. Only used in extreme circumstances 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

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

Glycemic Index (GI) Glycaemic 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

Glycemic Index of Common Foods VCE Physical Education - Unit 3

Comparative Results for High and Low GI Meals VCE Physical Education - Unit 3

The Three Energy Systems Foods, Fuels and Energy systems

Aerobic Exercise Aerobic exercise includes lower intensity activities performed for longer periods of time. Activities like walking, jogging, swimming, and cycling require a great deal of oxygen to make the energy needed for prolonged exercise. The energy system that is used in aerobic exercise is called the aerobic system . It can also be called ‘oxygen system’ or the ‘aerobic glycolysis system’. VCE Physical Education - Unit 3

Anaerobic Exercise The term "anaerobic" means "without air" or "without oxygen." Anaerobic exercise uses muscles at high intensity and a high rate of work for a short period of time. Anaerobic exercise helps us increase our muscle strength and stay ready for quick bursts of speed. Examples of anaerobic exercise include heavy weight lifting, sprinting, or any rapid burst of hard exercise. These anaerobic exercises cannot last long because oxygen is not used for energy and a by-product, called lactic acid, is produced. There are two energy systems which use the anaerobic pathways; ATP-PC (Alternatively called; ‘Alactacid’, ‘Creatine Phosphate’ or ‘Phosphogen system’) and the Lactic Acid systems (Also called ‘Anaerobic glycolysis’ or ‘Lactacid’) VCE Physical Education - Unit 3

Common Mistake The three energy systems do not turn on and off like a traffic light. They are always in operation – the relative contribution of each system varies depending on factors such as intensity, type of activity and duration . VCE Physical Education - Unit 3 X

The ATP-PC System Foods, Fuels and Energy Systems

The ATP-PC System Quickest system Breaks down phosphocreatine (PC) to form ATP anaerobically. However, PC stores require time to replenish. Dominant system for the first 10-15 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 Body has a larger storage of PC compared to ATP PC stores can be replenished through aerobic recovery. Once PC stores are depleted, they body must use glycogen through the anaerobic pathway. VCE Physical Education - Unit 3

The Lactic Acid System Foods, Fuels and Energy Systems

The Lactic Acid System The lactic acid 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. 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), 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

Complete the data analysis task on page 99-100 of Nelson Physical Education VCE Units 3 & 4. Coursework 4.1 VCE Physical Education - Unit 3

The Aerobic System Foods, Fuels and Energy Systems

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 lactic system 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 4.4 p.101 and 4.5 p.102 How the system works; CHOs and Tryglycerides (FFA + glycerol) broken down to release energy. This produces pyruvic acid. Pyruvic acid is further broken down producing carbon dioxide (Kreb’s cycle) Further breakdown via the electron transport chain. It requires hydrogen ions and oxygen, producing water and heat. VCE Physical Education - Unit 3

Anaerobic and Aerobic Glycolysis VCE Physical Education - Unit 3

Complete the laboratory tasks on page 104 and 105-6 of Nelson Physical Education VCE Units 3 & 4. Coursework 4.2 and 4.3 VCE Physical Education - Unit 3

Energy System Interplay Foods, Fuels and Energy Systems

Interplay Between Energy Systems 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

Aerobic Contributions VCE Physical Education - Unit 3

Anaerobic v Aerobic Contributions VCE Physical Education - Unit 3

Complete the data analysis task on page 109-111 of Nelson Physical Education VCE Units 3 & 4. Complete the laboratory task on page 111-3 of Nelson Physical Education VCE Units 3 & 4. Coursework 4.4 and 4.5 VCE Physical Education - Unit 3

Duration and Intensity VCE Physical Education - Unit 3 Duration of event Intensity of event Primary energy system(s) 0-6 seconds very intense ATP-PC 6-30 seconds intense ATP-PC and Lactic Acid 30 sec. - 2 minutes heavy Lactic Acid 2-3 minutes moderate Lactic Acid and Aerobic > 3 minutes light Aerobic

Comparing the Three Energy Systems Foods, Fuels and Energy Systems

High Intensity Competition VCE Physical Education - Unit 3

Complete the review questions 1-9 page 116 of Nelson Physical Education VCE Units 3 & 4. Test Your Knowledge VCE Physical Education - Unit 3

Complete the chapter questions on page 20-28 of Nelson Peak Performance Physical Education VCE Units 3 & 4. Peak Performance VCE Physical Education - Unit 3

Read the summarised information of pages 38-46 of PHYS ED Notes and complete the revision questions. PHYS ED Notes VCE Physical Education - Unit 3

VCAA Questions - 2006 VCE Physical Education - Unit 3

VCE Physical Education - Unit 3 Web Links – Chapter 4 VCE Board of Studies – additional information about energy systems: http://vcaa.vic.edu.au/vce/studies/physicaledu/EnrgSys.pdf Heart Foundation Australia: http://www.heartfoundation.com.au Australian Institute of Sport – sports nutrition: http://www.ais.org.au/nutrition/ Nutrition Australia: http://www.nutritionaustralia.org/ Dietician's Association of Australia: http://www.daa.asn.au/ Sports Coach UK – energy pathways: http://www.brianmac.demon.co.uk/energy.htm ‘ How stuff works’ – How exercise works: http://health.howstuffworks.com/sports-physiology6.htm Info about the glycemic index: http://www.glycemicindex.com/ Australian Sports Commission: http://www.ausport.gov.au Find 30 promotion (Government of WA Department of Health): http://www.find30.com.au Walking School Bus promotion (UK): http://www.walkingbus.com Ministry of Health (New Zealand) toolkits: http://www.newhealth.govt.nz The 10,000 Steps Rockhampton project: http://www.10000steps.org.au/rockhampton/ Travelsmart Australia: http://www.travelsmart.gov.au World Health Organisation: http://www.who.int Heart Foundation Australia: http://www.heartfoundation.com.au VicHealth (The Victorian Health Promotion Foundation): http://www.vichealth.vic.gov.au Be Active promotion (Government of South Australia): http://www.beactive.com.au Go For Your Life: http://www.goforyourlife.vic.gov.au Physical Activity Resources for Health Professionals – Introduction (Centre for disease control and prevention – USA): http://www.cdc.gov/nccdphp/dnpa/physical/health_professionals/index.htm Health Promotion (Public Health Agency of Canada): http://www.phac-aspc.gc.ca/hp-ps/index.html Strategic Inter-Governmental Forum on Physical Activity and Health (SIGPAH): http://www.nphp.gov.au/workprog/sigpah/ Healthy youth (Centre for disease control and prevention (USA): http://www.cdc.gov/HealthyYouth/ America On The Move promotion: http://www.americaonthemove.org Papers from the International Journal of Behavioural Nutrition and Physical Activity: http://www.ijbnpa.org/home Department of health and aging (Australian government): http://www.health.gov.au/internet/wcms/publishing.nsf/content/home Building a healthy, active Australia (Australian government): http://www.healthyactive.gov.au National Public Health Partnership: http://www.nphp.gov.au Be Active promotion (Government of South Australia): http://www.beactive.com.au Sport and Recreation Australia: http://www.sport.vic.gov.au

Chapt 4

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Chapt 4