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Chapter 4 presentation
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VCE Physical Education - Unit 3
Chapter 4Foods, fuels and energy systemsText Sources
1. Nelson Physical Education VCE Units 3&4: 4th Edition – Malpeli, Horton, Davey and Telford 2006.
2. Live It Up 2: 2nd Edition – Smyth, Brown, Judge, McCallum and Pritchard 2006.
Food Fuels
Foods, Fuels and Energy systems
VCE Physical Education - Unit 3
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)
Energy
VCE Physical Education - Unit 3
Foods High in CHO, Fats and Proteins
VCE Physical Education - Unit 3
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
Adenosine Triphosphate (ATP)Foods, fuels and energy systems
VCE Physical Education - Unit 3
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
VCE Physical Education - Unit 3
Food Fuels at Rest
Rest (Aerobic) Fat and glucose are the preferred fuelsDuring Exercise1. 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
Maximal and Sub-maximal Activity
Contributions of Carbohydrates, Fats and Protein to Energy
ProductionFoods, Fuels and Energy systems
VCE Physical Education - Unit 3
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.
Aerobic Anaerobic
Intensity increases
VCE Physical Education - Unit 3
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
Complete questions 1-4 page 92 of Nelson Physical Education VCE Units 3 & 4.
Checkpoints
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 antibodiesProtein and exercise1. Not used as a fuel, therefore low priority.2. Only used in extreme circumstances3. 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
Complete questions 1-2 page 94 of Nelson Physical Education VCE Units 3 & 4.
Checkpoints
The Three Energy Systems
Foods, Fuels and Energy systems
VCE Physical Education - Unit 3
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. X
The ATP-PC System
Foods, Fuels and Energy Systems
VCE Physical Education - Unit 3
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
VCE Physical Education - Unit 3
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
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
The Aerobic System
Foods, Fuels and Energy Systems
VCE Physical Education - Unit 3
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;
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
Anaerobic and Aerobic Glycolysis
VCE Physical Education - Unit 3
VCE Physical Education - Unit 3
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
Energy System Interplay
Foods, Fuels and Energy Systems
VCE Physical Education - Unit 3
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
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
VCE Physical Education - Unit 3
VCE Physical Education - Unit 3
High Intensity Competition
VCE Physical Education - Unit 3
Complete questions 1-4 page 114 of Nelson Physical Education VCE Units 3 & 4.
Checkpoints
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
VCAA Questions - 2006
VCE Physical Education - Unit 3
VCAA Questions - 2006
VCE Physical Education - Unit 3
Web Links – Chapter 4•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
•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/