1. Chapter 5 1 Energy for Muscular Activity

2. Where do we get Energy for our working muscles?

3. The Three Energy Nutrients  Carbohydrates  Proteins  Fats © iStockphoto.com/”og-vision/OlgaLIS” © iStockphoto.com/”Roman Chmiel” © iStockphoto.com/”Kativ”

4. Carbohydrates Carbohydrates are broken down into glucose and stored into the muscle as glycogen. Most easily broken down into this state which is why they are the first thing our body uses as a form of energy.

5. Proteins Proteins are broken down into amino acids. Proteins are used for energy when the body is in starvation mode.

6. Fats Fats are broken down in to fatty acids and a glycerol. Fats are the LAST energy source which is used.

7. Metabolism All the chemical reactions in the body that occur in the production of energy to do work (i.e. muscle work, 7

8. Bioenergetic Conversion The process by which our body converts the energy found in carbohydrates, proteins and fats into a more usable form, Adenosine Triphosphate (ATP). 8

9. 3 phosphates are present ATP = Adenosine TRI Phosphate

10. Adenosine Triphosphate (ATP)  Adenosine triphosphate (ATP)  ATP is a usable form of energy for the body.  Made in the mitochondrion  Resynthesized in two ways  Aerobically  Anaerobically ATP ADP + Pi + ENERGY

11. Recall the Hydrolysis of ATP Equation ATP + H 2 0 ADP + P i + Energy 11

12. ATP is the molecule that gives every cell in our body energy to function. All things in our body require energy in order to be able to function properly. –Food metabolism –Heart beat –Muscles contract

13. When you need energy it is on. When you don’t need energy it is being stored and not used.

14. 2 ways to re-synthesize ATP

15. Aerobic System

16. Two Energy Systems  Aerobic System  In the presence of oxygen (O 2 )  All of its metabolic activity will involve O 2  Occurs in the mitochondria  Leads to the complete breakdown of glucose  Lag period (slow to reach peek production)  Longer duration activities

17. With the presence of oxygen you are able to perform an activity over a long period of time with a balanced intensity.

18. What is an example of “aerobic activity” –Requires oxygen How does your body react? –Heart rate increases –Breathing increases

19. Anaerobic

20. Without oxygen (O 2 ) Occurs in cytoplasm Produces ATP immediately when needed Fast rate of ATP production Quick burst & shorter duration activities Needed for short and medium length activities. –Ex: weight lifting, short shifts in hockey

21. These systems are not in opposition These systems do not work in isolation, both systems are always contributing to some extent. All sporting events require some contribution from both systems. The body has three (3) primary metabolic pathways to resynthesizing ATP as it is used up and/or needed during exercise. 21 Energy spectrum: Anaerobic Aerobic

22. Three Metabolic Pathways 22

23. Three Metabolic Pathways Within the ANAEROBIC and AEROBIC systems, there are 3 metabolic pathways by which ATP energy reserves are restored: –ATP-PC pathway (anaerobic alactic) –Glycolysis pathway (anaterobic lactic) –Cellular respiration (aerobic) 23

24. High Energy Phosphate System 24 Creatine P P ENERGY ADP + P i  ATP

25. PC + ADP ATP + CREATINE ATP-PC System  ATP-PC System (anaerobic alactic)  First of two anaerobic energy pathways  Relies on the action of stored ATP and phosphocreatine  Yields enough ATP for 7-12 seconds of energy  Provides highest rate of ATP synthesis

26. ATP-PC Plays an important role in sporting events which only last a few seconds, but require large bursts of energy. –Ex: Olympic weight lifting, high jump, 50-100 m dash. HOWEVER – muscles do not have large supplies of phosphocreatine, and after about 10-15 seconds, body begins to rely on the second system.

27. High Energy Phosphate System Overview 27 Primary energy source: Duration of activity: Sporting events: Advantages: Limiting factors: Stored ATP, CP 7 to 12 s Weightlifting, high jump, long jump, 100 m run, 25 m swim Produces very large amount of energy in a short amount of time Initial concentration of high energy phosphates (ATP, PC)

28. The Anaerobic Glycolytic System 28 ADP + P i  ATP ENERGY Lactic Acid Glycogen

29. Glycolysis A biochemical process that releases energy in the form of ATP from glycogen and glucose anaerobic process (in the absence of oxygen) The products of glycolysis (per molecule of glycogen): - 2 molecules of ATP - 2 molecules of pyruvic acid The by-product of glycolysis (per molecule of glycogen): - 2 molecules of lactic acid 29

30. The Anaerobic Glycolytic System Starts when: –the reserves of high energy phosphate compounds fall to a low level –the rate of glycolysis is high and there is a buildup of pyruvic acid 30

31. Anaerobic Threshold The exercise intensity at which lactic acid begins to accumulate within the blood The point during exercise where a person begins to feel discomfort and burning sensations in the muscles Lactic acid is used to store pyruvate and hydrogen ions until they can be processed by the aerobic system 31

32. Substrates for the anaerobic energy system The primary source of substrates is carbohydrate Carbohydrates: –primary dietary source of glucose –primary energy fuels for brain, muscles, heart, liver 32

33. 33 Glucose stored in blood Glycogen stored in muscle or liver Complex Carbohydrates Digestive system Glycogen Glucogenesis Circulation of glucose throughout body Glucose Blood Stream Carbohydrate breakdown and storage

34. LACTIC ACID CHALLENGE

35. What is lactic acid challenge? This is a class challenge. –Find an place on the wall, and the person who can perform a wall sit for the longest – will win a prize! Describe what you felt that made you want to stop?

36. What is lactic acid? After 2 or 3 minutes of a sustained activity the body can not break down glucose fast enough to keep up. Lactic Acid builds up in the muscle fibers You are forced to slow down/stop – as it causes pain/discomfort in the muscle.

37. 37 The Anaerobic Glycolytic System Overview Primary energy source: Duration of activity: Sporting events: Advantages: Limiting factors: Stored glycogen, blood glucose 12 s to 3 min Lactic acid build up, H+ ions build up (decrease of pH) 800 m run, 200 m swim, downhill ski racing, 1500 m speedskating Ability to produce energy under conditions of inadequate oxygen

38. The Role of Three Energy Systems During an All-out Exercise Activity of Different Duration 38