1. Bioenergetics of Exercise Reading: Essentials of S&C 73-91 Christopher T. Ray, Ph.D., ATC, CSCS

2. Extra Credit Opportunity #1

3. Housekeeping Schedule Schedule –Assessments with partners Next Wed & Fri Next Wed & Fri –Sign in 9:00-9:05; Assessments 9:00–9:35 Plan accordingly Equipment = Calipers, S&R Box, VERTEC, Tape Measurer, cones, masking tape, courts, indoor track & weight room. Equipment = Calipers, S&R Box, VERTEC, Tape Measurer, cones, masking tape, courts, indoor track & weight room. Questions?

4. What? What does Exercise Rx mean to you? What does Exercise Rx mean to you? What do mean when I say “Be Evidence Based” What do mean when I say “Be Evidence Based”

5. Why Did Usain Bolt not Run the 400 meters? WR 100 meters = 9.69 WR 200 meters = 19.30 WR 400 meters = 43.18; 43.75 = Gold *45.29

6. Table 5.3 Effect of Event Duration on Primary Energy System Used DurationIntensityPrimary energy of eventof eventsystem(s) 0-6 sVery intensePhosphagen 6-30 sIntensePhosphagen and fast glycolysis 30 s-2 minHeavyFast glycolysis 2-3 minModerateFast glycolysis and oxidative system > 3 minLightOxidative system

7. Practice Sport Sport Assessment Assessment Training Regime (Int., Duration, Rest) Training Regime (Int., Duration, Rest)

8. Calculations 200 meter PR = 20; Training 75% - 90%; Recovery = 1:3-1:5 – –20 X 1.10 = 22 X 5 = 110 sec. – –20 X 1.25 = 25 X 3 = 75 sec.

9. “Wolff’s Law” The body adapts to the stress placed upon it. law according to which biologic systems such as hard and soft tissues become distorted in direct correlation to the amount of stress imposed upon them.

10. Bio-energetics is dynamic

11. 1. The Principle of Individuality 2. The Principle of Specificity 3. The Principle of Progressive Overload 4. The Principle of Hard / Easy 5. The Principle of Periodization 6. The Principle of Disuse Basic Training Principles

12. 1. The Principle of Individuality Different people respond to the same training in different ways. Heredity plays a major role in determining how quickly and to what degree the athlete adapts to a training program. For these reasons any training program “ must take into account the specific needs and abilities of the individuals for whom it is designed. ”

13. Basic Training Principles 2. The Principle of Specificity To maximize the benefits, training must be specifically matched to the type of activity the athlete use to be engaged in. (endurance vs strength and power training). By this principle the training program must stress the physiological systems that are critical for optimal athlete ’ s performance, in order to achieve specific adaptations for specific sports.

14. 3. The Principle of Progressive Overload Overload and Progressive Training are the foundation of all training programs. A well-designed Training Program must involve working the muscles, respiratory and cardiovascular systems harder than normal (overload); as the body adapts, Training progresses to a higher work level (progressive training) Basic Training Principles

15. 4. The Principle of Hard / Soft Bill Bowerman (former U.S. Olympic track coach and founder of NIKE) developed a training strategy for his distance running that became known as ‘ The principle of hard / soft ’. According to this principle, one or two days of hard training should be followed by one day of soft training, allowing the fully recover of body and mind and prevent the athlete ’ s overtraining. Basic Training Principles

16. 5. The Principle of Periodization Periodization is the gradual cycling of specificity, intensity and volume of training to achieve peak levels of fitness for competition. Basic Training Principles

17. 6. The Principle of Disuse “ Use it or loose it ” According to this principle, training benefits are lost if training is either discontinued or reduced too abruptly. To avoid this, all training programs must include a maintenance program. Basic Training Principles

18. Opportunity to get back on my good side #1 Pick a sport Pick a sport –What are the components –Where does it fit on the bioenergetics spectrum? How would you train athletes in this sport? How would you train athletes in this sport? How would you Assess them? How would you Assess them?

19. Introduction -Energy Ability to do work Ability to do work –Bioenergetics Flow of energy in a biological system Flow of energy in a biological system –Catabolism Breakdown of larger molecules into smaller molecules (glucose to pyruvate) Breakdown of larger molecules into smaller molecules (glucose to pyruvate) –Anabolism Synthesis of larger molecules from smaller molecules (polypeptide from AA residuals) Synthesis of larger molecules from smaller molecules (polypeptide from AA residuals)

20. Introduction –Exergonic reactions Energy-releasing reaction; generally catabolic reaction Energy-releasing reaction; generally catabolic reaction Ex. Blood glucose during catabolism = release of energy Ex. Blood glucose during catabolism = release of energy –Endergonic reactions Energy-consuming reaction; generally anabolic reaction Energy-consuming reaction; generally anabolic reaction Ex. Protein synthesis Ex. Protein synthesis –Metabolism Total of all the catabolic/exergonic and anabolic/endergonic reactions in a system Total of all the catabolic/exergonic and anabolic/endergonic reactions in a system

21. Introduction –ATP Adenosine triphosphate; intermediate molecule that allows the transfer of energy from exergonic to endergonic reactions Adenosine triphosphate; intermediate molecule that allows the transfer of energy from exergonic to endergonic reactions –Smallest usable form of energy

22. Biological Energy Systems –Three energy systems used to replenish ATP Phosphagen Phosphagen –Occurs in the sarcoplasm –An anaerobic energy system Glycolytic Glycolytic –Occurs in the sarcoplasm –An anaerobic energy system Oxidative Oxidative –Occurs in the mitochondria –An aerobic energy system

23. Biological Energy Systems Phosphagen system (anaerobic), occurs without oxygen. Phosphagen system (anaerobic), occurs without oxygen. Glycolysis (Fast & Slow) is the breakdown of carbohydrates, either glycogen stored in the muscle or delivered in the blood to produce ATP. Glycolysis (Fast & Slow) is the breakdown of carbohydrates, either glycogen stored in the muscle or delivered in the blood to produce ATP. Oxidative system is the primary source of ATP at rest and low-intensity, it uses primarily carbohydrates and fats as substrates. Oxidative system is the primary source of ATP at rest and low-intensity, it uses primarily carbohydrates and fats as substrates. All three energy systems are active at a given time; the extent to which each is used depends on the intensity of the activity and its duration.

24. Biological Energy Systems All energy systems are active at any given time All energy systems are active at any given time –The extent of their contribution: Primary Primary –Intensity, power output, work rate Secondary Secondary –Duration

25. Phosphagen System –Primary functions Provide ATP for high intensity activities (e.g., sprinting, weight training) Provide ATP for high intensity activities (e.g., sprinting, weight training) For 0-6 seconds up to 20-30 seconds of activity For 0-6 seconds up to 20-30 seconds of activity Active at the start of all exercise Active at the start of all exercise –Regardless of intensity!

26. Summary of Phosphagen System –Summary: Rapid ATP resynthesis rate Rapid ATP resynthesis rate Efficient system (due to the few number of involved reactions) Efficient system (due to the few number of involved reactions) –Creatine kinase reaction –Myokinase reaction BUT a low capacity of total ATP produced BUT a low capacity of total ATP produced

27. Glycolytic System –Primary functions Carbohydrate (CHO) (i.e., blood glucose and muscle glycogen) break down to produce ATP in the sarcoplasm of a muscle cell Carbohydrate (CHO) (i.e., blood glucose and muscle glycogen) break down to produce ATP in the sarcoplasm of a muscle cell –Provides energy primarily for moderate to high intensity activities –For 30 seconds up to 2-3 minutes of activity –Hypoxic (anaerobic) cellular environment

28. Glycolytic System Fate of pyruvate Fate of pyruvate –High rate of energy demand –Insufficient O2 present –Fast glycolysis (pyruvate to lactate) –Example: 1200 meter sprint run Low rate of energy demand Low rate of energy demand –Sufficient O2 present –Slow glycolysis (pyruvate [with NADH] is sent to the Krebs Cycle in the mitochondria) –Example: 30 minute stair climbing workout

29. Summary of Fast Glycolysis Fast glycolysis occurs during reduced oxygen availability and the end product is lactic acid. Fast glycolysis occurs during reduced oxygen availability and the end product is lactic acid. Lactic acid accumulation in tissue is the result of an imbalance of production & utilization. Lactic acid accumulation in tissue is the result of an imbalance of production & utilization. As lactic acid accumulates, there is an increase in the concentration of H ++ ions. As lactic acid accumulates, there is an increase in the concentration of H ++ ions. H ++ ions inhibit glycolytic reactions. H ++ ions inhibit glycolytic reactions. H ++ ions interfere with E-C coupling by inhibiting Ca from binding with troponin. H ++ ions interfere with E-C coupling by inhibiting Ca from binding with troponin. The decrease in pH also inhibits enzymatic activity. The decrease in pH also inhibits enzymatic activity.

30. Lactic Acid and Lactate Lactic acid is converted to its salt, lactate, by buffering systems in the muscle and blood. Lactic acid is converted to its salt, lactate, by buffering systems in the muscle and blood. Lactate is not fatigue producing, it is often used as an energy system in Type I and cardiac muscle. Lactate is not fatigue producing, it is often used as an energy system in Type I and cardiac muscle. Lactate is used in gluconeogensis, the formation of glucose from lactate and non-carbohydrate sources during extended exercise and recovery. Lactate is used in gluconeogensis, the formation of glucose from lactate and non-carbohydrate sources during extended exercise and recovery. Concentrations of lactate in blood and muscle: Concentrations of lactate in blood and muscle: –At rest, 0.5 – 2.2 mmol/L –At high intensity exercise 20 – 25 mmol/L Peak blood lactate concentrations occur approximately 5 minutes after the cessation of exercise. Peak blood lactate concentrations occur approximately 5 minutes after the cessation of exercise. Blood lactate accumulation is greater following high- intensity intermittent exercise, than lower intensity continuous exercise. Blood lactate accumulation is greater following high- intensity intermittent exercise, than lower intensity continuous exercise.

31. Oxidative System - Primary function –Provide ATP for low intensity activities (e.g., long distance running, cycling, swimming) –For longer than 3 minutes of activity –Substrates CHO CHO Fats Fats Proteins Proteins –Reactions occur in the mitochondria “Power house” of the muscle cell “Power house” of the muscle cell

32. Oxidative (Aerobic) System  Requires molecular oxygen  Uses primarily carbohydrates and fats as substrates  Provides ATP at rest and during low-intensity activities  At rest, 70% of ATP is from fats & 30% carbs.  As exercise intensity increases there is a shift from fats to carbohydrates as substrates.  At high intensity, almost 100% of ATP is from carbs.  During prolonged, submaximal steady state work, there is a gradual from carbs back to fats & proteins.

33. Summary of Oxidative System –Adaptations to training Increased muscle mitochondrial content Increased muscle mitochondrial content More effective sparing of CHO for use by the central nervous system More effective sparing of CHO for use by the central nervous system Blunted drop in intracellular pH during a long- term aerobic endurance event Blunted drop in intracellular pH during a long- term aerobic endurance event

34. Substrate Depletion and Repletion –Energy substrates used to produce ATP –Phosphagen –Glycogen –Glucose –Lactate –Free fatty acids –Amino acids

35. Substrate Depletion and Repletion –Phosphagen and ATP Depletion Depletion –Creatine phosphate (CP) stores can decrease 50- 70% in the first 5-30 seconds –CP stores are virtually eliminated as a result of high intensity exercise –ATP stores do not decrease more than 60% even with very intense exercise

36. Substrate Depletion and Repletion –Phosphagen and ATP Repletion Repletion –Post-exercise resynthesis of ATP can occur within 3-5 minutes –Post-exercise resynthesis of CP may require up to 8 minutes –Most post-exercise CP resynthesis is accomplished through oxidative energy pathways

37. Oxidative system yields 38 ATP from 1 glucose molecule. Oxidative system yields 38 ATP from 1 glucose molecule.

38. Energy Production and Capacity –Rate and capacity of the three energy systems to supply ATP Inverse relationship Inverse relationship Rate (how fast ATP can be created) Rate (how fast ATP can be created) Capacity (how much ATP can be created) Capacity (how much ATP can be created)

39. Table 5.4 Rankings of Rate and Capacity of ATP Production SystemRate of ATPCapacity of ATP productionproduction Phosphagen15 Fast glycolysis24 Slow glycolysis33 Oxidation of carbs42 Oxidation of fats and proteins51 1 = fastest/greatest; 5 = slowest/least

40. Energy Production and Capacity

42. T he use of appropriate exercise intensities and rest intervals allows for the “selection” of specific energy systems during training and results in more efficient and productive regimens for specific athletic events with various metabolic demands. 

43. Substrate Depletion and Repletion ATP and creatine phosphate, glucose, glycogen, lactate, FFA and amino acids can be selectively depleted. ATP and creatine phosphate, glucose, glycogen, lactate, FFA and amino acids can be selectively depleted.

44. Phosphagen Depletion & Repletion Phosphagens are more rapidly depleted with high intensity exercise than aerobic exercise. Phosphagens are more rapidly depleted with high intensity exercise than aerobic exercise. Creatine Phosphate decreases 50-70% during high intensity exercise and can be almost eliminated by exercise to exhaustion Creatine Phosphate decreases 50-70% during high intensity exercise and can be almost eliminated by exercise to exhaustion Muscle ATP concentrations do not decrease by more than 60% of initial value even during intense exercise. Muscle ATP concentrations do not decrease by more than 60% of initial value even during intense exercise. Intramuscular ATP is spared by the depletion of creatine phosphate from the myosine kinase reaction. Intramuscular ATP is spared by the depletion of creatine phosphate from the myosine kinase reaction. Post exercise repletion of phosphagen with: Post exercise repletion of phosphagen with: –Resynthesis of ATP in 3 – 5 min –Complete creatine phosphate resynthesis in 8 min Resistance training can result in an increase in the resting concentration of phosphagens. Resistance training can result in an increase in the resting concentration of phosphagens.

45. Glycogen Depletion & Repletion Limited stores of glycogen are available for exercise, approx. 300- 400 g in total body muscle and 70-100 g in the liver. Limited stores of glycogen are available for exercise, approx. 300- 400 g in total body muscle and 70-100 g in the liver. Anaerobic training can increase glycogen stores. Anaerobic training can increase glycogen stores. Muscle glycogen is more important than liver during moderate – intense exercise. Muscle glycogen is more important than liver during moderate – intense exercise. Liver glycogen is more important in low intensity exercise and its contribution increases with duration. Liver glycogen is more important in low intensity exercise and its contribution increases with duration. Repletion of muscle glycogen during recovery is related to post exercise carbohydrate consumption. Repletion of muscle glycogen during recovery is related to post exercise carbohydrate consumption. Repletion is optimal if 0.7 – 3.0 g of carbs/kg is ingested every 2 hrs. Repletion is optimal if 0.7 – 3.0 g of carbs/kg is ingested every 2 hrs. Muscle glycogen may be completely replenished within 24 hrs with sufficient carbs in diet. Muscle glycogen may be completely replenished within 24 hrs with sufficient carbs in diet.

46. Glycogen depletion can be a limiting factor both for: Glycogen depletion can be a limiting factor both for: –Long duration, low intensity exercise –Repeated very high – intensity exercise Lactic acid and tissue H ++ ion concentration can be limiting factors for resistance training, sprinting and other anaerobic activities. Lactic acid and tissue H ++ ion concentration can be limiting factors for resistance training, sprinting and other anaerobic activities.

47. Low-Intensity, Steady-State Exercise Metabolism EPOC = Excess postexercise oxygen uptake At the start of exercise, some of the energy is provided by anaerobic metabolism. At the start of exercise, some of the energy is provided by anaerobic metabolism. The anaerobic contribution to the total energy cost is termed Oxygen Deficit. The anaerobic contribution to the total energy cost is termed Oxygen Deficit. Post-exercise oxygen uptake remains elevated according to intensity and duration and is termed Oxygen Debt. Post-exercise oxygen uptake remains elevated according to intensity and duration and is termed Oxygen Debt.

48. High-Intensity, Non-Steady-State Exercise Metabolism

49. Phosphagen System

50. –Enzymes used to hydrolyze ATP (the location determines which one will be used) Myosin ATPase Myosin ATPase Sodium-Potassium ATPase Sodium-Potassium ATPase Calcium ATPase Calcium ATPase

51. Summary of Glycolytic System Energy yield of glycolysis (Figure 3) Energy yield of glycolysis (Figure 3) –From glucose: 2 ATP –From muscle glycogen: 3 ATP With slow glycolysis: With slow glycolysis: –2 NADH are transported to the mitochondria where they each produce 3 ATP (total of 6 ATP) via oxidative phosphorylation

52. Krebs Cycle

53. Electron Transport Chain

54. Total Energy Yield (one glucose molecule)

55. Oxidative System Fat (Beta) Oxidation Fat (Beta) Oxidation

56. Total Energy Yield (one triglyceride molecule)

57. Summary of the Metabolic Systems

58. Energy Production and Capacity

59. Substrate Depletion and Repletion –Energy substrates used to produce ATP –Phosphagen –Glycogen –Glucose –Lactate –Free fatty acids –Amino acids

60. Substrate Depletion and Repletion –Phosphagen and ATP Depletion Depletion –Creatine phosphate (CP) stores can decrease 50- 70% in the first 5-30 seconds –CP stores are virtually eliminated as a result of high intensity exercise –ATP stores do not decrease more than 60% even with very intense exercise

61. Substrate Depletion and Repletion –Phosphagen and ATP Repletion Repletion –Post-exercise resynthesis of ATP can occur within 3-5 minutes –Post-exercise resynthesis of CP may require up to 8 minutes –Most post-exercise CP resynthesis is accomplished through oxidative energy pathways

62. Substrate Depletion and Repletion –Phosphagen and ATP Repletion: work:rest ratio recommendations Repletion: work:rest ratio recommendations

63. Substrate Depletion and Repletion –Glycogen Depletion Depletion –The higher the exercise intensity, the faster the depletion rate –Selective glycogen depletion (i.e., depletion within involved musculature) can cause early fatigue even if the whole body’s glycogen stores are not depleted Repletion Repletion –(Immediate) post-exercise CHO ingestion is critical

64. Practice Sport Sport Assessment Assessment Training Regime (Int., Duration, Rest) Training Regime (Int., Duration, Rest) Be Evidence Based!