Presentation on theme: "Year 12 Physical Education PHYSIOLOGICAL REQUIREMENTS OF PHYSICAL ACTIVITY Foods Fuel and Energy Systems AREA OF STUDY 2."— Presentation transcript:
Year 12 Physical Education PHYSIOLOGICAL REQUIREMENTS OF PHYSICAL ACTIVITY Foods Fuel and Energy Systems AREA OF STUDY 2
WHAT YOU NEED TO KNOW AT THE END OF CHPT 4: The Conversion of food to energy Food fuels at rest and during exercise The Glycemic Index Energy for Muscular Contraction The Aerobic and Anaerobic energy systems The contribution of energy systems to various activities The Energy System Interplay
Where does this energy come from? A Maria Sharapova serve takes 1-2 seconds to perform. Its fast & explosive. She might do this hundreds of time over a game. Plus she has to run fwd, bkwd and sideways for 1-2 hours. Her Muscles requires ENERGY to do this.
In the Tour De France, Alexander Vinokourov rides 220km a day Like Sharapovas serve, Vinos muscles require energy to ride for this amount of time. And then do it again tomorrow, and the next day…etc… It takes 6 + hours, its slower & less intense. Where does this energy come from?
Food Fuels our Body 1. CARBOHYDRATES (Glycogen) 2. PROTEIN 3. FATS
CARBOHYDRATES Cereals Breads Pastas Rice Sugar Carbohydrates are stored as Glycogen in Muscle & Liver CHO is the bodys preferred fuel during Exercise – breaks down easily, uses little oxygen Fruit/Veges
PROTEIN Red Meat Eggs Dairy products Fish Poultry Protein is stored as MUSCLE and AMINO ACIDS around the body. GRAINS 5-10% contribution to endurance events: Mainly used for growth/repair
Food that we ingest is stored and burnt to fuel our muscles This food must be converted into a chemical compound called ATP Without ATP, Muscles cannot contract
ATP Adeonsine Triphosphate APPP The energy for muscle contraction is derived when one of the 3 phosphate bonds is broken Every muscle contraction Ben Cousins performs must have ATP available to it… ATP ADP + P + ENERGY We end up with:
ATP is a very heavy compound, so we cannot store much of it in our muscles. Can only store about 1 SECOND worth in muscle (allows 1 or 2 contractions to occur – eg Start of 100m or a Netball shot) For further contraction to occur ATP must be REMADE or produced ATP ADP + P + ENERGY
How is ATP remade? The Body uses THREE DIFFERENT ENEGRY SYSTEMS to do this.
For activity lasting: 0-10 SEC ATP-PC SYSTEM 10-30/40 SEC LACTIC ACID SYSTEM 30 + SEC- 2MINS AEROBIC SYSTEM
ATP-PC & LACTIC ACID SYSTEM ARE BOTH CLASSIFIED AS ANAEROBIC ENERGY SYSTEM This means that the muscles do not need OXYGEN to produce ATP Energy. They use STORED ENERGY. The AEROBIC system takes Time to become involved. It cannot provide Oxygen quick enough for short, fast activities.
ATP-PC SYSTEM Uses stores of CP (Creatine Phosphate) to REMAKE ATP Only have 10 seconds of CP in muscles CP instantly available, but runs out quickly Used for high intensity Jumps, Throws, Sprints If activity lasts longer than 10 sec, ATP must be REMADE by some other means…..
LACTIC ACID SYSTEM Body uses stored fuel of GLYCOGEN to REMAKE ATP Downside – by-product called Lactate. Hydrogen Ions also released which inhibit muscle contraction Need Oxygen to do this properly Happens because of lack of enough Oxygen to break down Glycogen 400m run, 800m at high intensity About 2-3 hours of glycogen stored in body.
AEROBIC SYSTEM Used in longer, sub- max activities. Long run, swim, cycle. Plenty of Oxygen available to remake ATP. So no LA or H+ is accumulated Oxygen supply meets demand Will keep suppling ATP for as long as Fitness levels allow We use this system at REST (Now!) – except we burn… FAT!!!! Like the LA system, the Aerobic uses Glycogen to remake ATP.
During REST Any rest, short OR Long, CP is being replenished, so we can sprint again. BUT, need 3 minutes rest to get all CP back! Any Lactate and Hydrogen Ions are removed from muscles & blood stream too.
Things to remember: The 3 Energy Systems are not like TRAFFIC LIGHTS. One does not switch off and another goes on. All 3 turn on at once no matter what the activity. However, depending on intensity and duration of the activity, ONE system will contribute more than the other TWO.