2. Energy Systems

3. Storage of Food Fuels in the Body

4. Digestion 101 http://www.youtube.com/watch?v=q3986Yfl5cU

5. The Animal Cell

6. ATP Requirements ATP Requirements of 70kg male in a 24 hr period Amount of Stored ATP available 50g Required ATP in 24hr period 190kg

7. ATP and Muscle Contraction Adenosine Triphosphate Molecule Chemical Structure

8. Adenosine Triphosphate Pi Adenosine Triphosphate Molecule: the bonds between the phosphate molecules break – energy is liberated. End product = ADP (Adenosine Diphosphate)+ Free Phosphate Molecule

9. Energy Systems The systems used to resynthesis of ATP depend on a number of factors including: Duration Intensity If sufficient level of oxygen is present Urgency of energy required Athletes level of training

10. The Energy Systems The Energy Systems and their alternative names 1. The ATP-PC Energy System Alactacid System Creatine Phosphate or Phosphate Creatine System Phosphagen system 2. The Lactic Acid Energy System Anaerobic glycolysis Lactacid System 3. The Aerobic Energy System Oxygen system Aerobic glycolysis

11. The ATP-PC Energy System Quickest ENERGY system – simple chemical reactions that occur in the cytoplasm of the cell 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. PC releases a free phosphate

12. The ATP-PC Energy System

13. The LACTIC ACID Energy System Activated at the start of intense exercise: More complex reactions than the ATP-PC system – occurs in the cytoplasm Peak power until it fatigues (2-3 minutes) Predominant energy supplier in events 85% of maximum Heart Rate eg. 200m sprint.

14. The LACTIC ACID Energy System Glycogen is broken down in the absence of sufficient levels of oxygen at the cell site (Anaerobic glycolysis) The lactic acid system provides twice as much energy for ATP resynthesis than the ATP-PC system. This produces a fatigue causing by product called lactic acid. Lactic acid makes the muscle pH decrease (More acidic), reducing ATP resynthesis.

15. The LACTIC ACID Energy System

16. ANAEROBIC Respiration

17. The AEROBIC Energy System The aerobic system Slowest contributor to ATP resynthesis – occurs in the Mitochondria Produces more ATP than the two anaerobic pathways Becomes the predominant pathway for ATP production 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)

18. Comparison of Aerobic and Anaerobic Glycolysis

19. Interplay of the Energy Systems All energy systems start contributing ATP at the onset of work. At different times during the activity one energy pathway will be the predominant pathway for generating ATP. The predominant pathway depends upon the intensity and duration of the work phase.

20. Oxygen Uptake & Delivery Oxygen Deficit The period after the onset of exercise where the ATP demands are being met via anerobic pathways The available oxygen is less than that required to produce all the ATP via aerobic pathways

21. Oxygen Uptake & Delivery Steady State A period of time where oxygen supply to the working muscles equals the demand of the muscle A steady state can occur at various stages throughout an event in response to the oxygen demands until the intensity reaches a point where the body cannot deliver enough oxygen to the muscles to meet the demand.

22. Oxygen Uptake & Delivery EPOC (Excess Post Exercise Oxygen Consumption) An activity performed at a lower intensity will have a longer steady state and a smaller oxygen debt A person who has undertaken aerobic training will be able to: Consume a greater amount of oxygen during steady state The anaerobic pathways contribute less to work in the early stages of the event.

23. Oxygen Uptake & Delivery EPOC (Excess Post Exercise Oxygen Consumption) The oxygen that is consumed above resting levels to deliver to the working muscles in response to anaerobic work. There are two components to EPOC – alactacid debt and lactacid debt The body can repay the debt simultaneously

24. Oxygen Uptake & Delivery Alactacid debt – replenishing the Creatine-Phosphate stores (Passive recovery) Lactacid debt – involves the removal of the lactic acid (active recovery)