Energy Systems and Muscle Fibre Types

1. Energy Systems and Muscle Fibre Types

2. In groups of 2 answer the following… • Why do we eat? • Answer- Nutrients and Energy needed for daily activities/bodily functions

3. Cont… • What Foods provide us with Energy? • Answer – The foods that yield Energy are known as Energy Yielding foods and can be classified as Carbohydrates (CHO’s), Fats, and proteins

4. Cont… • How does the body convert these foods into Energy? • Answer- Bioenergetic Conversion, Foods are broken down into their smallest units (glucose, fatty acids, and amino acids). These Units are then eventually converted into a high energy storing molecule called ATP, which in turn can be broken down by the body’s cells releasing energy!

6. Exercise Metabolism • ATP --- ADP + Pi + Energy

7. Energy Systems • The body produces Energy aerobically or Anaerobically through one of it’s three metabolic pathways. • The body prefers to satisfy it’s energy (work) requirements through aerobic methods (with oxygen)…..eg walking • However, as the intensity of work/activity increases the body will recruit other pathways to help produce the needed Energy.

8. ATP • Adenosine Triphosphate • Captures the chemical energy resulting from the breakdown of food and stores it in the high energy phosphate bonds. • See O.H. (ATP)

9. Anaerobic Energy Systems • Can you name some high intensity activities?

10. Anaerobic Energy Systems

11. Aerobic Energy System • Can you name some lower intensity activities that are longer in duration?

12. Aerobic Energy System

13. Spinning Lab Activity Instructions for the subject:  • This is a single blind study, thus the subject is unaware of the specifics of the test. • The subject must pedal as hard as they can for the duration of the trial. The subject may stop if they feel uncomfortable at any time. • In order to target the legs the rider should try to lean forward while pedaling at the hips with arms resting on the bars. • The student will be permitted to have a pedaling start and will hit top speed when the first whistle blows.

14. Spinning Lab Activity • Instructions for the observers: • In order to keep track of the revolutions keep track of the number of times that the subject’s right foot reaches the bottom of the pedaling rotation. • Only count for your segment! (Time slot assigned to you)

15. Spinning Lab Activity • Compare and contrast each of the individual riders and their background/history, What if any differences do you anticipate in their results?, Explain. • After compiling all of the scores and averages for each category. Calculate the riderss aveerage RPMs for each time segment. • Graph all riders on the same graph for easy comparison.

16. Spinning Lab Activity • What were the overall/general trends that you saw in the results. Did they concure with teachings from the course/text? • Compare and contrast the individual trends. Do you feel the athlete’s background/history contributed in any way to the findings? Explain.

17. Spinning Lab Activity • Discuss experimental errors or uncertainties which may have occurred or been present. • What factors or method design would you change if we had to perform this again in order to achieve more accuracy?

18. Spinning Lab Activity • See H.O.

21. Three Energy Pathways • Anaerobic Alactic (ATP-PC) • Anaerobic Lactic (anerobic glycolysis, (incomplete)) • Aerobic Respiration (aerobic/complete glycolysis)

23. Anaerobic Alactic (ATP – CP) System • Simplest of the energy systems. • Creatine Kinase (enzyme) helps break up Creatine Phosphate in the muscle into Cr + Pi + Energy (this energy will be used to bind Pi + ADP, can not be used for cellular work) • CP is in limited supply within the muscle, thus this system supplies a large amount of energy but CP levels decline rapidly as it is used up as the system replenishes ATP stores. • ATP-CP system only lasts 3-10sec during an all out sprint.

25. Anaerobic Lactic System • Production of ATP through the breakdown (Lysis) of glucose via special glycolytic enzymes called glycolysis. • Before either glucose or glycogen can be used to generate energy, they must be converted to G-6-P (glucose 6 phosphate). • This process requires 1 molecule of ATP for glucose, but not for glycogen.

26. Anaerobic Lactic System • Glycolysis begins once G-6-P is formed and ultimately produces pyruvic acid. • This process does not require oxygen but oxygen determines the fate of pyruvic acid (discuss later) • When oxygen is not present pyruvic acid becomes lactic acid. • This system is much more complex than the ATP-CP system, but can provided energy for up to 2-3 minutes during intense activity. • Like ATP-PC, this occurs in the sarcoplasm of a muscle cell

27. Anaerobic Lactic System • The limitation of this system is the build up of lactic acid, which inhibits further glycogen breakdown, because it impairs glycolytic enzyme function. Enzymes are proteins which are highly affected by temperature as well as pH level. As Lactic acid levels increase during activity, it is thought that this slows/inhibits glycolytic enzymes….end result is decreased rate of glycolysis…thus the rate of ATP production decreases……and you get fatigued….RESULT = you slow down or are unable to sustain that exercise intensity!

28. Anaerobic Lactic System • THE CORI CYCLE: - Process by which lactic acid is transported to the liver and converted back to pyruvate and eventually back to glycogen. - The cori cycle takes place between skeletal muscle and the liver.

29. Aerobic Alactic System • This oxidative production of ATP occurs within the mitochondria. • Unlike anaerobic ATP production the oxidative system has a tremendous energy yield. • Yields about 36 ATP per molecule of glucose. • Oxidative process involves 3 stages: - Glycolysis, - Krebs Cycle, - Electron Transport Chain

30. Aerobic Alactic System • GLYCOLYSIS: - Breakdown glucose or glycogen into pyruvic acid. - In the presence of oxygen, pyruvic acid is converted into a compound called acetyl CoA, which enters the Krebs Cycle. - 2 ATP produced

31. Aerobic Alactic System • THE KREBS CYCLE (Citric Acid Cycle): - Is complex series of chemical reactions that produces CO2, ATP, and hydrogen ions. - 2 ATP are produced per glucose molecule.

32. Aerobic Alactic System • ELECTRON TRANSPORT CHAIN: - Large amounts of ATP are produced with CO2 and water as the by-products. - Total of 32 ATP are produced.

34. Aerobic System Cont… • What are the limitations of the aerobic system? • Fuel source (CHO, Fat, Protein) and Oxygen must be available! • The rate of ATP utilization must be slow enough to allow aerobic system to keep pace otherwise body will turn to other systems to generate ATP

35. Healthy Heart and Lungs! • How might a healthy circulatory system benefit you during a sporting event? OR • How might an unhealthy circulatory system hinder someone during activity?

36. Healthy Heart and Lungs! • If the heart and lungs can not effectively pump enough oxygen to the tissues, then the system will shift to anaerobic pathways! • Training effect!...ability to do more work (i.e. use ATP with the same effort) • Individuals with healthy hearts and lungs can deliver more oxygen to their tissues and remain aerobic longer or at higher intensities!