The human body uses three main energy systems - the ATP-PCr system, anaerobic glycolysis, and oxidative phosphorylation - to produce energy for muscle contraction. The ATP-PCr system provides energy for intense bursts of activity lasting up to 10 seconds. Anaerobic glycolysis is used for activities lasting 20 seconds to 2 minutes and produces lactic acid as a byproduct. Oxidative phosphorylation provides virtually unlimited energy through aerobic metabolism for endurance activities lasting several minutes or more.

1. Energy Systems for Exercise

6. Cells in the body need energy to function FOOD=ENERGY (E)

8. Glucose

9. The glucose is then used in 3 different ways… Here some of the glucose is stored as glycogen and used to maintain blood sugar levels. Glucose is stored here as glycogen and is used when the body is working harder. Glucose diffuses easily into the cells and is used to meet their energy demands. Skeletal Muscle Liver Body Cells

10. Cells don’t get Energy directly from food, it must be broken down into: ATP -Adensosine TRIphosphate ATP = a form of energy one can immediately use, it is needed for cells to function & muscles to contract

13. D. Matthews and E. Fox, in their revolutionary book, "The Physiological Basis of Physical Education and Athletics", divided the running requirements of various sports into the following "energy pathways": ATP-CP and LA, LA-02, and 02. ATP - Adenosine Triphosphate : a complex chemical compound formed with the energy released from food and stored in all cells, particularly muscles. Only from the energy released by the breakdown of this compound can the cells perform work. The breakdown of ATP produces energy and ADP. CP - Creatine Phosphate: a chemical compound stored in muscle, which when broken down aids in the manufacture of ATP. The combination of ADP and CP produces ATP.

14. 3. LA - Lactic acid : a fatiguing metabolite of the lactic acid system resulting from the incomplete breakdown of glucose. However Noakes in South Africa has discovered that although excessive lactate production is part of the extreme fatigue process, it is the protons produced at the same time that restrict further performance 4 . O2 means aerobic running in which ATP is manufactured from food mainly sugar and fat. This system produces ATP copiously and is the prime energy source during endurance activities

25. The ATP Molecule Adenosine Adenosine Energy a. Adenosine Triphosphate (ATP) b. The breakdown of ATP: P P P P P P ATP = ADP + energy for biological work + P (ADP = Adenosine Diphosphate) Energy for cellular function

26. For contractions to continue… ATP must be REBUILT This comes from the splitting of CP (Creatine Phosphate a Hi energy source, automatic) When ATP is used – it is rebuilt – as long as there is CP Energy released from CP breaking down, resynthesizes the ADP & P

27. REMEMBER – only small amounts of ATP are stored = only 2-3 sec. of Energy ATP-CP = 8-10 sec. of Energy The usefulness isn’t the AMOUNT of Energy but the QUICK & POWERFUL movements For longer periods of work = The Aerobic & Anaerobic Energy System must be utilized

28. The Immediate Resynthesis of ATP by CP Creatine P Creatine P Energy High energy bond a. Creatine Phosphate (CP) b. CP = Creatine + energy for resynthesis of ATP + P Adenosine P P P c. ADP + energy from CP + P = ATP (reversal of ATP = ADP + P + energy for work)

30. Since glycogen is stored in the muscle & liver, it is available quickly This system provides ATP when ATP-CP runs out Again, ATP-CP lasts for a few seconds, the Anaerobic Energy System allows for 2-3 minutes of work

35. 4. Anaerobic Energy System = Carbohydrates are the only fuel source 5. With prolonged exercise, Carbohydrates are the first fuel choice, as exercise continues, FAT becomes predominant 6. Protein is not a main fuel source except in an emergency

39. Examples Anaerobic Anaerobic 2 Aerobic

41. Aerobic Respiration – With Oxygen 1. Glucose and oxygen are transported to the working muscles by the blood. Aerobic respiration involves the release of energy from the slow breakdown of glucose using oxygen, inside the cells. 2. Glucose and oxygen are then used by the muscles of the body to produce energy. 3. This process creates carbon dioxide and water. 4. The carbon dioxide passes back into the blood for removal. The Process of Aerobic Respiration Energy for Muscles to contract and create Movement Water Carbon Dioxide Glucose Oxygen

42. Aerobic respiration is how marathon runners produce the energy that is used in long periods of less intensive effort. Glucose and oxygen produce…

43. Aerobic respiration is how marathon runners produce the energy that is used in long periods of less intensive effort. Glucose and oxygen produce… Some is used for muscle contractions, creating movement.

44. Aerobic respiration is how marathon runners produce the energy that is used in long periods of less intensive effort. Glucose and oxygen produce… Carbon dioxide, which is carried away by the blood & excreted through the lungs. Water, which is carried away by the blood and excreted through the lungs, sweat and urine. Some is used for muscle contractions, creating movement. The rest is converted into heat to warm the body.

45. Anaerobic respiration involves the release of a little energy, very quickly from the incomplete breakdown of glucose without using oxygen, inside the cells. 1. Glucose is made available by the breakdown of glycogen stored in the working muscles. 2. The glucose is used by the muscles of the body to produce energy, without the use of oxygen. 3. This process creates lactic acid, which passes back into the blood for removal. Anaerobic Respiration – Without Oxygen The Process of Anaerobic Respiration Glucose Energy for muscles to contract and create movement Lactic Acid

47. Oxygen Debt Question: How do sprinters pay back their oxygen debt at the end of a race? Answer: Sprinters will continue to breathe more deeply and rapidly for a number of minutes at the end of their race. This will enable them to pay back the oxygen debt, and allow lactic acid levels to fall.

48. Anaerobic Respiration is how sprinters produce the energy that is used in short periods of ‘all out effort’ - high intensity. Glucose Produces… Oxygen cannot reach the muscles fast enough, so anaerobic respiration is used.

49. Anaerobic Respiration is how sprinters produce the energy that is used in short periods of ‘all out effort’ - high intensity. Glucose produces… Lactic acid quickly builds up & makes the muscles feel tired & painful. ‘All out effort’ cannot last for very long! Oxygen cannot reach the muscles fast enough, so anaerobic respiration is used. Some is used for muscle contractions, creating movement.

50. Anaerobic Respiration is how sprinters produce the energy that is used in short periods of ‘all out effort’ - high intensity. Glucose produces… Lactic acid quickly builds up & makes the muscles feel tired & painful. ‘All out effort’ cannot last for very long! The rest is converted into heat to warm the body. Oxygen cannot reach the muscles fast enough, so anaerobic respiration is used. Some is used for muscle contractions, creating movement.