Year 12 Physical Education AREA OF STUDY 2 PHYSIOLOGICAL REQUIREMENTS OF PHYSICAL ACTIVITY Foods Fuel and Energy Systems

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. It’s 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. Where does this energy come from?

Where does this energy come from? In the Tour De France, Alexander Vinokourov rides 220km a day Where does this energy come from? It takes 6 + hours, it’s slower & less intense. Like Sharapova’s serve, Vino’s muscles require energy to ride for this amount of time. And then do it again tomorrow, and the next day…etc…

Food Fuels our Body 1. CARBOHYDRATES (Glycogen) 2. PROTEIN 3. FATS

CARBOHYDRATES Pastas Cereals Rice Fruit/Veges Breads Sugar Carbohydrates are stored as Glycogen in Muscle & Liver CHO is the body’s preferred fuel during Exercise – breaks down easily, uses little oxygen

PROTEIN Fish Red Meat Poultry Eggs Dairy products GRAINS Protein is stored as MUSCLE and AMINO ACIDS around the body. 5-10% contribution to endurance events: Mainly used for growth/repair

FATS Butter Oils Margarine Nuts Cheese

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 Every muscle contraction Ben Cousins performs must have ATP available to it… ATP Adeonsine Triphosphate A P P P The energy for muscle contraction is derived when one of the 3 phosphate bonds is broken We end up with: ATP ADP + P + ENERGY

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 CP instantly available, but runs out quickly Uses stores of CP (Creatine Phosphate) to REMAKE ATP Used for high intensity Jumps, Throws, Sprints Only have 10 seconds of CP in muscles If activity lasts longer than 10 sec, ATP must be REMADE by some other means…..

LACTIC ACID SYSTEM Need Oxygen to do this properly Body uses stored fuel of GLYCOGEN to REMAKE ATP Need Oxygen to do this properly About 2-3 hours of glycogen stored in body. Downside – by-product called Lactate. Hydrogen Ions also released which inhibit muscle contraction Happens because of lack of enough Oxygen to break down Glycogen 400m run, 800m at high intensity

Used in longer, sub-max activities. Long run, swim, cycle. AEROBIC SYSTEM Plenty of Oxygen available to remake ATP . So no LA or H+ is accumulated Used in longer, sub-max activities. Long run, swim, cycle. Like the LA system, the Aerobic uses Glycogen to remake ATP. Oxygen supply meets demand We use this system at REST (Now!) – except we burn… Will keep suppling ATP for as long as Fitness levels allow FAT!!!!

BUT, need 3 minutes rest to get all CP back! 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.

All 3 turn on at once no matter what the activity. Things to remember: 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. The 3 Energy Systems are not like TRAFFIC LIGHTS. One does not switch off and another goes on.