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Edexcel Examinations A Level Physical Education A 9536 Unit 6 : Section A part 3

Edexcel Examinations A Level Physical Education A 9536 Unit 6 : Section A part 3 Scientific Principles of Exercise and Performance. 20 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM / AT REST 21 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM

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Edexcel Examinations A Level Physical Education A 9536 Unit 6 : Section A part 3

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  1. Edexcel ExaminationsA Level Physical EducationA 9536 Unit 6 : Section A part 3 Scientific Principles of Exercise and Performance

  2. 20 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM / AT REST 21 - SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM 22 - SHORT-TERM EFFECTS OF AEROBIC EXERCISE - a-vO2 diff 23 - SHORT-TERM METABOLIC RESPONSE TO AEROBIC ACTIVITY 24 - LONG-TERM VASCULAR ADAPTATIONS TO AEROBIC TRAINING 25 - LONG-TERM METABOLIC ADAPTATIONS TO AEROBIC TRAINING 26 - LONG-TERM NEUROMUSCULAR ADAPTATIONS TO AEROBIC TRAINING 27 - FOOD FUEL UTILISATION DURING AEROBIC EXERCISE GLYCOGEN SPARING 28 - ONSET OF BLOOD LACTATE ACCUMULATION (OBLA) LONG-TERM ADAPTATIONS OF OBLA TO AEROBIC TRAINING 29 - CELLULAR ADAPTATION PRODUCED BY AEROBIC TRAINING 30 - GENERAL LONG-TERM ADAPTATIONS PRODUCED BY TRAINING INDIVIDUAL RESPONSE / SWEATING / REGRESSION 31 - GENERAL LONG-TERM CELLULAR ADAPTATIONS TO TRAINING NEURAL / MUSCLE CELLS Index 3 - ERGOGENIC AIDS 4 - ERGOGENIC AIDS CARBOLOADING 5 - ERGOGENIC AIDS CREATINE / GLUTAMINE / CAFFEINE / ALCOHOL 6 - ERGOGENIC AIDS - BLOOD DOPING / rEPO 7 - ERGOGENIC AIDS ALTITUDE TRAINING - PSYCHOLOGICAL / THERAPIES 8 - ERGOGENIC AIDS - MECHANICAL 9 - ERGOGENIC AIDS AMPHETAMINES / BETA BLOCKERS / HGH ANABOLIC STEROIDS 10 - RESPONSES TO TRAINING 11 - THE ENERGY CONTINUUM VARIATION IN CONTRIBUTION OF ENERGY SYSTEMS 12 - HIGH INTENSITY EXERCISE SHORT-TERM RESPONSES 13 - THE LACTIC ACID SYSTEM EFFECTS OF CONTINUED HIGH INTENSITY EXERCISE 14 - THE LACTIC ACID SYSTEM OBLA 15 - FOOD FUEL USAGE DURING HIGH INTENSITY EXERCISE DURING HIGH INTENSITY EXERCISE 16 - LONG-TERM ADAPTATIONS TO HIGH INTENSITY TRAINING ANAEROBIC 17 - LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH (ANAEROBIC) TRAINING MUSCLE CELL RESPONSE 18 - LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH(ANAEROBIC) TRAINING 19 - LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH (ANAEROBIC) TRAINING NEURAL / CONNECTIVE TISSUE RESPONSES INDEX

  3. Fatigue and Recovery Process ERGOGENIC AIDS

  4. Fatigue and Recovery Process ERGOGENIC AIDS ERGOGENIC AID • any substance or method which enhances performance NUTRITIONAL DIETARY MANIPULATION CARBOLOADING • aims to raise muscle glycogen stores above their normal resting levels • prior to endurance competitions with over 90 minutes continuous activity • suitable for activities with low anaerobic and high aerobic components • based on : • depletion - prolonged exercise to reduce levels of liver and muscle glycogen stores - at least seven days before event • repletion - a high CHO diet in the period (three to four days) before activity • combined with light exercise or rest • also suitable for activities lasting 15 - 20 minutes • with a two day high CHO diet beforehand (see previous slides)

  5. Fatigue and Recovery Process ERGOGENIC AIDS NUTRITIONAL DIETARY MANIPULATION CREATINE SUPPLEMENTATION • creatine is a substance found in skeletal muscle • stored as phosphocreatine (PC) • supplementation increases PC levels to enhance the ATP-PC system of ATP resynthesis • thereby delaying the alactic / lactic threshold GLUTAMINE • is an amino acid forming part of skeletal muscle and immune cells • supplementation after exercise therefore reinforces the immune system and reduces the risk of infection CAFFEINE • stimulates the CNS but acts as a diuretic - this can lead to dehydration • illegal in large quantities ALCOHOL • a relaxant in quite small quantities • absorbed into the body as an alternative to water therefore causes dehydration • quite small quantities of alcohol can cause a drastic loss of performance

  6. Fatigue and Recovery Process ERGOGENIC AIDS ILLEGAL PHYSIOLOGICAL BLOOD DOPING • involves the removal of athlete’s own blood which is then stored • the athlete’s body then remanufactures blood to replace that taken • then the stored blood is reinfused • this temporarily increases red blood cell count (polycythemia) • problem of mis-matching can lead to a transfusion reaction • increases VO2max and hence energy delivery to enhance aerobic performances rEPO • involves infusion of hormone recombinant erythropoietin 6 weeks prior to major event • stimulating erythrocytes (up to 10% more) - red blood cells • increases VO2max and hence energy delivery to enhance aerobic performances • but elevates red blood cell production that can reach toxic life-threatening levels • other risks are blood clots, strokes / coronary thrombosis, very low resting heart rates

  7. Fatigue and Recovery Process ERGOGENIC AIDS LEGAL PHYSIOLOGICAL ALTITUDE TRAINING • a predominantly endurance-based exercise programme used by elite endurance athletes from a range of sports • consisting of 2 visits of at least two weeks duration per visit, to altitude (normally between 1800-3000 metres) • second visit just prior to major competition • training at altitudeuses the fact that the body will create more haemoglobin • to compensate for the reduction in oxygen available • benefits : reversible physiological adaptations • increased Hb concentration • increases in myoglobin mitochondria and oxidative enzymes • hence on return to sea level we have an increased VO2max and tissue cell respiration leading to enhanced aerobic performance • risks : hypoxia, altitude sickness PSYCHOLOGICAL • imagery / hypnosis stimulate mental rehearsal of relevant skills • by activating neural pathways that reinforce skill THERAPIES • physiotherapy / acupuncture / herbal medicines used in injury treatment • reduce muscle soreness and aid recovery of local damaged tissue

  8. Fatigue and Recovery Process ERGOGENIC AIDS MECHANICAL NASAL STRIPS • use of sticky plaster placed over bridge of nose to enlarge nasal cavity • enables easier breathing SPECIALIST EQUIPMENT • carbon fibre bike frames are lighter and aerodynamically more efficient • specialist training machines • concept II ergo rower • swimming ergo • flumes for rowing / swimming / canoeing • treadmill SPECIALIST CLOTHING • cycling helmets and lycra sports clothing reduces air resistance • Denise Lewis one shoulder javelin suit, bench press and squatting suits • provide extra force in required directions

  9. Fatigue and Recovery Process ERGOGENIC AIDS ILLEGAL PHARMACEUTICAL AMPHETAMINES • act as CNS stimulants to increase arousal levels BETA BLOCKERS • reduce HR and BP thereby reducing tension, but can lead to heart failure HUMAN GROWTH HORMONE (HGH) • stimulates bone growth and increased lean body mass • give artificial increased strength / power outputs ANABOLIC STEROIDS • increase lean body mass, but reduce natural secretions of gonadotrophins • females acquire masculine features such as facial and body hair and deep voices • give artificial increased strength / power outputs

  10. Short / Long-term Responses RESPONSES TO TRAINING HIGH INTENSITY SHORT DURATION LOW INTENSITY LONG DURATION

  11. Short / Long-term Responses THE ENERGY CONTINUUM VARIATION IN CONTRIBUTION OF ENERGY SYSTEMS • as time progresses during intense exercise, the following chart shows the contribution of the different energy systems to the resynthesis of ATP

  12. Short / Long-term Responses HIGH INTENSITY EXERCISE SHORT-TERM RESPONSES ATP muscle stores are depleted within 2 seconds ATP/PC system • rising ADP levels stimulate the breakdown of PC stores • in coupled reaction with ADP pool • peak anaerobic power attained within first 5 seconds of flat-out exercise • depletion of PC occurs between 7-9 seconds • on the graph, the ATP level is maintained (after an initial small drop) then falls as PC is used up • by the energy from PC being used to resynthesise ATP • so PC levels fall rapidly • capacity to maintain ATP production at this point depends on lactic acid system

  13. Short / Long-term Responses THE LACTIC ACID SYSTEM EFFECTS OF CONTINUED HIGH INTENSITY EXERCISE • glycolysis or incomplete breakdown of glucose molecule • small energy yield of 2ATP per glucose molecule • dominant between 10-60 seconds • increased lactic acid production to and beyond lactic threshold (OBLA) see next three slides • reduced pH inhibits glycolytic enzymes GPP, PFK and LDH • increased muscle fatigue and pain • delayed onset of muscle soreness(DOMS) occurring 24-48 hours after exercise • particularly following plyometric (eccentric) training • produces a marked reduction in physical performance • capacity to maintain ATP production then begins to rely on the aerobic system

  14. Short / Long-term Responses THE LACTIC ACID SYSTEM OBLA • as work intensity increases lactic acid starts to accumulate above resting values • at a certain point this produces muscle fatigue and pain • the resultant low pH inhibits enzyme action and cross-bridge formation • hence muscle action is inhibited • physical performance deteriorates • OBLA depends on the level of training • and lies between 2 and 4 mmol l-1

  15. Short / Long-term Responses FOOD FUEL USAGE DURING HIGH INTENSITY EXERCISE DURING HIGH INTENSITY EXERCISE

  16. Short / Long-term Responses LONG-TERM ADAPTATIONS TO HIGH INTENSITY TRAINING LONG-TERM ADAPTATIONS TO AN ANAEROBIC TRAINING PROGRAMME • increases in stores of ATP and PC • and amounts of anaerobic enzymes such as creatine kinase • result in more energy to be available more rapidly • andtherefore increases in maximum possible peak power • and a delay in the ATP/PC to lactic threshold

  17. Short / Long-term Responses LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH (ANAEROBIC) TRAINING MUSCLE CELL ADAPTATIONS (FAST TWITCH FIBRES) • muscle hypertrophy (of fast twitch fibres) increases cross sectional area of existing fibres by increasing : • number of myofibrils within each muscle cell • sarcoplasmic volume • contractile proteins : actin and myosin • mass of fast twitch fibres • number of fast twitch fibres (hyperplasia) • hence % of type II increases and % of type I decreases • increase in muscle cell stores such as ATP, PC, and glycogen • increase in anaerobic enzymes such as creatine kinase (CK), PFK, GPP, and LDH • increase toleration of lactate in fast twitch fibres • improved ability to remove lactate from muscle cell into blood • therefore enhancement of alactic / lactate and lactate / aerobic thresholds - delay in OBLA • hence improved capacities of alactic and lactic acid systems to resynthesise ATP • and ability to maintain maximal power output for longer • decrease in DOMS, particularly following eccentric training

  18. Short / Long-term Responses LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH(ANAEROBIC) TRAINING AFTER SEVERAL WEEKS OF STRENGTH (ANAEROBIC) TRAINING MUSCLE CELL BEFORE TRAINING ATP CP glycogen glycolytic enzymes lactic acid ATP CP glycogen glycolytic enzymes lactic acid = SLOW TWITCH MUSCLE FIBRE (type I) (starts small gets smaller) =FAST TWITCH MUSCLE FIBRE (type II) (starts big gets bigger)

  19. Short / Long-term Responses LONG-TERM NEUROMUSCULAR ADAPTATIONS PRODUCED BY STRENGTH (ANAEROBIC) TRAINING NEURAL ADAPTIVE RESPONSE • increased rate of response of CNS (Central Nervous System) • recruitment of additional fast twitch fibre motor units • improved coordination of fast twitch fibre motor units • toughening of proprioceptors so that more force is required to stimulate inhibitorysignals CONNECTIVE TISSUE ADAPTATIONS • increase in thickness and strength of tendons • increased flexibility of ligaments • thickening and improved elasticity of cartilage • strengthening of bone tissue due to increased depositing of calcium • therefore reduced risk of injury

  20. Short / Long-term Responses SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM • unlimited supply of energy • to sustain the forces needed during low intensity and long duration activity AT REST • ATP utilisation is slow • a mixture of fats and carbohydrates is used to resynthesise ATP • the graph shows that initially CHO is the major supplier of chemical energy • the longer the exercise the greater utilisation of fats • as muscle and liver glycogen stores become depleted

  21. Short / Long-term Responses SHORT-TERM RESPONSE TO AEROBIC ACTIVITY THE AEROBIC SYSTEM • requires CHO in the form of glucose • which is derived from glycogen stored in muscle cells (mostly ST slow twitch) • or in the liver • the graph shows how the rate of usage of muscle glycogen is high during the first 30 minutes of steady exercise • the amount of glycogen remaining • depends on the intensity and duration of the exercise • and the CHO content of diet prior to exercise • once the glycogen is used it may take days to fully replenish • again depending on diet

  22. Short / Long-term Responses a-vO2 diff note that the blood draining from working muscle tissue may be almost completely depleted of oxygen however, the mixed venous return would still have around 5ml/dl because it is a mixture of blood from the working muscles and less active parts of the body combined SHORT-TERM EFFECTS OF AEROBIC EXERCISE a-vO2 diff - AT REST venule capillary arteriole blood flow 15ml O2 per 100ml blood 20ml O2 per 100ml blood a-vO2 diff = 5ml per 100ml blood a-vO2 diff - DURING INTENSE EXERCISE venule capillary arteriole blood flow 5ml O2 per 100ml blood 20ml O2 per 100ml blood a-vO2 diff = 15ml per 100ml blood

  23. METABOLIC RESPONSE Short / Long-term Responses SHORT-TERM METABOLIC RESPONSE TO AEROBIC ACTIVITY • oxygen consumption or VO2 reflects the metabolic activity of the body and increases linearly with work • then it levels out as the pulmonary system reaches its maximum capacity for rate of absorption of oxygen • examples : Activity VO2 ml/kg/min-1 At rest 3.5 Walking 10 Jogging 20 At VO2max 55

  24. Short / Long-term Responses LONG-TERM VASCULAR ADAPTATIONS TO AEROBIC TRAINING VASCULAR ADAPTATIONS • arteriovenous oxygen difference(a-vO2diff) • a-vO2diff increases with training particularly at maximal workloads • due to increased oxygen extraction by active tissue • caused by : • more effective blood shunting • improved capillarisation of trained muscle • more efficient use of existing capillaries a-vO2 diff - AT REST venule capillary arteriole blood flow 15ml O2 per 100ml blood 20ml O2 per 100ml blood a-vO2 diff = 5ml per 100ml blood a-vO2 diff - DURING INTENSE EXERCISE venule capillary arteriole blood flow 5ml O2 per 100ml blood 20ml O2 per 100ml blood a-vO2 diff = 15ml per 100ml blood

  25. Short / Long-term Responses LONG-TERM METABOLIC ADAPTATIONS TO AEROBIC TRAINING LONG-TERM METABOLIC ADAPTIVE RESPONSE • example data of VO2max ml/kg-1min-1 • gender and training differences GroupAgeMaleFemale Non athletes 10-19 47-56 38-46 20-29 43-52 33-42 Basketball 18-30 40-60 43-60 Cross-country skiing 20-28 65-94 60-75 Gymnastics 18-22 52-58 36-50 Rowing 20-35 60-72 58-65 Runners18-39 60-85 50-75 • note that in the above data untrained females have much lower VO2max values (between 20-25%) compared with untrained males • whereas endurance-trained females have VO2max values much closer to those of endurance-trained males (about 10% lower)

  26. Short / Long-term Responses LONG-TERM NEUROMUSCULAR ADAPTATIONS TO AEROBIC TRAINING ADAPTATIONS PRODUCED BY AEROBIC TRAINING MUSCLE CELL ADAPTATIONS • more myoglobin is created in muscle cells • more and bigger mitochondria in muscle cells • increased oxidative enzymes glycogen phosphorylase, phosphofructokinase, lipoprotein lipase • hence increased activity of Kreb’s cycle and electron transport chain • and increase in stores and utilisation of fat • increase in stores of glycogen in muscle • which enables more fuel to be available for aerobic work • conversion of type IIb to type IIa fibres NEURAL ADAPTATIONS • better recruitment of slow twitch fibre motor units making muscle usage more efficient

  27. Short / Long-term Responses FOOD FUEL UTILISATION DURING AEROBIC EXERCISE GLYCOGEN SPARING AS A LONG-TERM ADAPTATION TO AEROBIC TRAINING • for the person who has undertaken sustained aerobic training • an adaptation is produced where fats are used earlier on in exercise • thus conserving glycogen stores (respiratory exchange ratio (RER) indicates greater use of fats) • the graph shows a higher proportion of fats utilised by the trained person • thereby releasing CHO for higher intensity work

  28. Short / Long-term Responses ONSET OF BLOOD LACTATE ACCUMULATION (OBLA) LONG-TERM ADAPTATIONS OF OBLA TO AEROBIC TRAINING • this point governs the lactic aerobic threshold • trained athletes begin OBLA at higher work intensities • and higher values of VO2max than untrained people

  29. Short / Long-term Responses CELLULAR ADAPTATION PRODUCED BY AEROBIC TRAINING AFTER SEVERAL WEEKS OF AEROBIC TRAINING BEFORE TRAINING glycogen fats oxygen uptake glycogen fats oxygen uptake = SLOW TWITCH MUSCLE FIBRE (type I) =FAST TWITCH MUSCLE FIBRE (type II) (do not increase in size)

  30. Short / Long-term Responses GENERAL LONG-TERM ADAPTATIONS PRODUCED BY TRAINING INDIVIDUAL RESPONSE • adaptive response depends on individual • fitness • cultural differences • gender • psychological factors • maturation SWEATING • improved ability to sweat • more efficient heat loss REGRESSION • when training stops, adaptive responses cease • the longer the training the more stable the adaptation

  31. NEURAL CELLS increased rate of firing of CNS, therefore increased stimulation of motor units therefore increased recruitment of FT and ST motor units MUSCLE CELLS increased rate of cellular respiration means increased O2 consumption or increased use of energy stores causes a decrease in PC and glycogen in ST and FT fibres decrease in triglycerides, oxymyoglobin stores increase in ADPs , Mg++,Ca++ reduced pHinhibits cellular enzymes resulting in a general increase in muscle fatigue as muscular performance reduces Short / Long-term Responses GENERAL LONG-TERM CELLULAR ADAPTATIONS TO TRAINING

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