Year 12 Phys Ed – Energy Systems Practice Questions
Multi Choice – Question 1 • Select the most likely cause of fatigue in performance as many push ups as possible in 10 seconds? • Local muscle glycogen depletion • H+ accumulation • PC depletion • None of the above
Question Two • The accumulation of ADP has been investigated as a potential source of muscular fatigue. This is most likely to occur when predominately using the following energy system;- • Aerobic system • ATP-PC system • Anaerobic System • ADP-PC system
Question Three • The lactate inflection point is best described as occurring when; • Oxygen consumption meets oxygen supply and OBLA occurs • Ventilation decreases in an effort to prevent large amounts of CO2 from accumulating • Athlete’s reach 85% VO2 Max • Lactic acid accumulates at a greater rate than which it can be oxidized and prevented from accumulating
Question 4 • Most of the PC depleted during Physical Activity will be re-synthesised during; • The first 3 mins of a passive recovery • The ‘fast part’ of EPOC • The first 30 mins when post exercise creatine monohydrate is consumed • All of the above
Short Answer – Question 1 • Most athletes undertake the 20 mtr shuttle run (beep test) to assess their aerobic capacity at various stages of the training year. • Recently a CD was released that allows athletes to run at Level 6, 8 or 10 without any increases in workload for 5 mins.
a) List the predominant fuel sources and energy system for the following stages of the test. • Waiting for the test to begin • Jogging the first 20 m • Jogging between cones during Level 6 • Sprinting between cones after missing 1 beep at Level 11 • Jogging between cones during Level 12 10 marks
Describe the energy system interplay likely to occur for a person capable of reaching Level 12 during;- • A) The first minute of the test 8 marks • B) the last minute of the test 8 marks
Question Two • What is the ‘extra’ oxygen taken in after the event has been finished used for in terms of assisting recovery? 3 marks
Question Three • Is it actually possible for athletes to perform at 110% VO2 max? • Briefly discuss how this is possible by making reference to the energy system(s) used. • 3 marks
Question Four • During a series of short sprints (4x 20 mtr sprints with 2 mins rest) both anaerobic energy systems are used (ATP-PC and Lactic Acid). • What is the most likely fatigue causing factor and explain how this would occur. • 2 marks
Answers • Multi-choice: • Qn 1 – C • Qn 2 – B • Qn 3 – D • Qn 4 - A
Answers – short answer qn’s Qn 1 • Waiting for the test to begin – Aerobic/Fats • Jogging the first 20 m- ATP-PC /CP • Jogging between cones during Level 6 – Aerobic/Glycogen (CHO) • Sprinting between cones after missing 1 beep at Level 11 – Lactic Acid/Glycogen (CHO) • Jogging between cones during Level 12- Aerobic/Glycogen (CHO)
Qn 2- The first minute of the test • All three energy systems start contributing to ATP production with the first step, with most coming from the ATP-PC system. The test is ‘slow paced’ to begin with so PC stores will not be depleted at the same rate as if they were being called upon for maximum activity and hence contribution to ATP production will last approximately 15 seconds. .....
.....The LA system increases its contribution to energy production as the test continues but doesn’t really come into play a great deal during the first minute. Most of the ATP is provided by the aerobic system due to the plentiful supplies of oxygen and the low intensity/demands for oxygen.
Answer: extra oxygen-Where?? • Resynthesise ATP and PC • Removing H+ ions • Restore oxygen to the muscles • Converts LA back to glycogen • Restores body temperature • Supplies o2 to the cardiovascular and respiratory systems
During last minute of the test • At level 12 the pace is quite fast and the PC stores would have essentially been depleted without any chance to be restored. The LA system would have increased its contribution to ATP production as the demand for oxygen exceeds the supply, but at this stage of the test the aerobic system would be the major ATP provider, even if the athlete is sprinting. • Why?
The aerobic system is capable of producing 20-30 times more ATP than both anaerobic systems combined and would have more than sufficient time to be activated.
110% VO2 max – how? • This occurs when energy is being supplied anaerobically, usually with aid of the lactic acid system. Due to the fact that oxygen required does not meet oxygen demand and needs to call upon another system to help supply the energy that’s needed.
Fatigue causing factor • Due to the fact that subject used the LA system predominantly there would be a build-up of;- • Metabolic By-products. • The build up of H+ ions when working in the LA system because the body can’t break them down. Muscles will stop functioning to the best of their ability with the build up of H+ ions.
SAC tips.... • Take a highlighter and underline/highlight any important KEY WORDS in the question. • Does question ask you for energy system, fuel source – read question carefully. • Try to put more info into your answers – better more than less. • Marks allocated generally = amount of points need to be made...more is better!
Use all your 100 mins. • Write notes on a piece of paper before converting it to your final SAC paper. • Re-read over your answers and check that you haven’t missed out on anything.