Anaerobic Energy Systems

1. Anaerobic Energy Systems By: Stacey Perkins, Catherine Gordon, Kaitlyn Souter, Ben O’Brien

2. Lab Overview • Look at definitions and types of anaerobic energy systems • Conduct Wingate Test • Collect and Analyse results • Re-group for questions and summary • IMPORTANT: Please be diligent and respond quickly to instructions

3. Anaerobic Energy Systems • Anaerobic energy system = energy system within the body that does not require the use of oxygen • It consists of the ATP-PC system and the Lactic Acid/Anaerobic Glycolysis system • All three energy pathways (ATP-PC, Lactic Acid & Aerobic energy systems) operate at any one time and can overlap. The contribution of each varies depending on the duration and intensity of the activity

4. Anaerobic Energy Systems ATP-PC SYSTEM • Provides a bulk of ATP required during powerful and explosive efforts (Eg: take off in high jump, sprint position in netball) • Linked with several fitness components (Eg: muscular strength, anaerobic power, speed) • Provides up to 10 seconds of energy for maximal effort • The system relies on muscle stores of both ATP and PC (phospho-creatine)

5. Anaerobic Energy Systems LACTIC ACID SYSTEM • Provides bulk of ATP production during high intensity, sub-maximal efforts. • Operates as a dominant supply of ATP from around 15-60 seconds of maximal effort • Closely linked with several fitness components (Eg: anaerobic power, speed and muscular power) • Classic example: 400m run

6. Definitions • SPEED: Refers either to the ability to perform a movement quickly or to see how fast a movement is performed. • POWER: The rate of performing work. The product of force and velocity. Power = force x distance/time.

7. Definitions • WORK: Physical work or effort as opposed to rest • VELOCITY: Velocity = distance/time. How fast an object is moving at any one time over a given distance with regard to direction. Two types: Linear and Angular.

8. Post Exercise Oxygen Consumption (EPOC) • Who here plays a sport? What? • After a short sprint/tackle what is your body doing? (in relation to your breathing and pulse) • Is it possible to not have an increased heart rate and heavy breathing after intense exercise? Why?

9. Post Exercise Oxygen Consumption (EPOC) • When aerobic exercise begins, the oxygen transport system does not immediately supply the needed quantity of oxygen to the active muscles because oxygen consumption requires several minutes to reach steady state. • Because oxygen needs and oxygen supply differs during the transition from rest to exercise, the body incurs an oxygen deficit. (eg: getting tired during warm up)

10. Post Exercise Oxygen Consumption (EPOC) • The oxygen deficit = the difference between the oxygen required for a given exercise intensity and the actual oxygen consumption. • Excess Postexercise Oxygen Consumption (Oxygen debt) = the elevated levels of oxygen consumption during the initial minutes of recovery, which exceed the oxygen usually required at rest.

11. Post Exercise Oxygen Consumption (EPOC)

12. Sources of Fatigue • PCr depletion • Muscle glycogen depletion • Neuromuscular - nerve impulses • CNS - muscular recruitment • Metabolic by-products • Lactate • Hydrogen Ions – low ph • Buffers - bicarbonate

13. Metabolic By-Product Removal LACTIC ACID: • Myth – that lactic acid is responsible for fatigue • Truth – lactic acid accumulates within the muscle fibre only during relatively brief, highly intense muscular effort. • Truth – fatigue is generally caused by inadequate energy supply • Lactate – Removed by Gluconeogenesis (conversion of glucose) through Cori cycle (energy consuming) or the Oxidation to pyruvate which fuels the citric acid cycle (energy producing)

14. Metabolic By-Product Removal HYDROGEN IONS • Hydrogen Ions (pH) – Removed by buffers such as bicarbonate • pH is a major limiter of performance and the primary cause of fatigue during maximal and all-out exercise

15. Wingate Test • Conduct the Wingate Test • All participants to prepare for testing • Observers prepare to record results

16. Blood Lactate • Why is blood lactate increased at post test? • Why does blood lactate continue to increase at follow up? • What are some gender differences in lactate?

17. Application of Results • Visit all four groups • Peak Anaerobic Power (PP) • Relative Anaerobic Power (RPP) • Anaerobic Capacity (AC) • Anaerobic Fatigue (AF) • Apply results from the Wingate test to above mentioned methods

18. Questions? • Does the term Anaerobic Capacity actually indicate the total amount of work done by the anaerobic systems? Why/why not? • What are the causes of Anaerobic fatigue in this test?

19. Questions? After the test has finished, how does the body get rid of lactic acid? • Exertion levels determine the rate of lactic acid removal • An active recovery provides best conditions with exertion levels and heart rate lower than that at the onset of blood lactate accumulation.

20. Questions? • The bulk of lactic acid is converted back into pyruvic acid then oxidised inside the mitochondria via the citric acid cycle (creating new ATP supplies) • The body also deals with lactic acid through respiration, perspiration and excretion.

21. Conclusion • Anaerobic energy system = energy system within the body that does not require the use of oxygen • There are two systems = ATP-PC system (lasts from 8-10 seconds) & LACTIC ACID system (operates from 15-60 seconds) • Excess Postexercise Oxygen Consumption (Oxygen debt) = the elevated levels of oxygen consumption during the initial minutes of recovery, which exceed the oxygen usually required at rest.

22. Conclusion • There are many sources of fatigue that can influence performance • The Metabolic by-products need to be removed from the system to enable the body to recover effectively • Have a good day!!