ANSWERS TO QUESTIONS

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1 SECTION 3.1 CHAPTER 1 ANSWERS TO QUESTIONS STUDENT NOTE Please note that most answers are not exact, and that equivalent answers are usually acceptable. CHAPTER 1: Short-term physiological preparation Text between pages 12 to 25, answers to questions on page 25 of the text book. 1) a) From a physiological standpoint, explain why warm-up is important within an exercise regime. 8 marks Warm-up: Raises body temperature. Increases metabolic rate. Raises energy release. Reduces response times. This increase in temperature reduces blood viscosity. And therefore increases blood flow to working muscles. Slightly increasing demand for oxygen will increase heart rate and breathing volumes. Which makes more oxygen available to working tissue. Blood supply is redistributed to working tissue (vascular shunt). A warm-up prepares the body for skill demands of the activity - reducing the risk of injury. b) Stretching is a key element in any warm-up. Using an example, identify two other elements of a warm-up and explain how they help to prepare an athlete. 4 marks Jogging: Gradually elevates heart rate and ventilation rates. Increases core temperature. Sport specific skill practice: This works the neuromuscular systems related to the chosen activity. c) Describe three different methods of stretching and state a sport that would benefit most from each type. 6 marks Passive stretching: This happens when the stretch is assisted by a partner or object to stretch the muscle beyond its normal range. Suitable for activities where movement range is important example gymnastics. Could be developed into PNF. Proprioceptive neuromuscular facilitation (PNF): PNF involves stretching. Followed by an isometric contraction. Followed by further stretching (PNF). Suitable for activities where range of movement is important, for example gymnastics. Static stretching: This is a form of stretching when the muscle is stretched to a point of tension. And then held for a time period. Very relevant to activities where static balance is important, for example gymnastics balance. Active stretching: Occurs when the stretch is done slowly to extend the joint. And stretch the muscle to an unassisted range of movement. Suitable for all sports. Ballistic stretching: Occurs when body movements are used in a swinging/bouncing fashion to extend joint range. Suitable for explosive events such as sprinting. 2

2 SHORT-TERM PREPARATION 2) Define energy, and briefly describe how energy is released from food in the body? 5 marks 1 mark for definition: Energy is the capacity or ability to perform work. 4 marks for energy is released from food in the body: Fuel foods are fuel stored in the body, the first is carbohydrate (CHO - digested to glucose). The second type of fuel food consists of fats (digested to fatty acids & glycerol). These are used to create chemical energy in the form of adenosine triphosphate (ATP). This is an endothermic reaction (it takes in energy from the food and creates the ATP). This process is both aerobic and anaerobic, within all living tissue. ATP is an immediate usable form of chemical energy for all body processes. Including that used by skeletal muscle to perform mechanical work. The usage of ATP to create energy is an exothermic reaction. 3) a) Prescribe a prudent recommendation for approximate percentages of protein, lipid and carbohydrate intake for a general all-round athletic performer. 3 marks CHO 50% - 60%. Lipid 25% - 35%. Protein 10% - 15%. b) Suggest some general dietary guidelines you would give to a gymnast who is preparing for a major competition. 3 marks Regular weighing. Limit fat intake. Increase liquid intake (rehydration). Maintain a balanced diet that stresses high CHO content. Use of food supplements such as creatine, glutamine, iron tablets and vitamin C. 4) Discuss the value of using protein supplementation to enhance performance in power and endurance events. 4 marks It was generally believed that protein supplementation was essential for athletes who train hard in power and endurance events. The role of protein differs for power-based and endurance-based athletes. The recommended daily allowance (RDA) is and grams per kilogram of body mass respectively. This is because the rate of protein breakdown and resynthesis is greater due to muscle hypertrophy. Providing the RDA of protein is included in the athlete s balanced diet there should be no reason for protein supplementation. However, recent studies have shown that supplementing protein immediately following heavy bouts of training seems to have a beneficial effect. Since elevation of plasma amino acids during recovery stimulates protein synthesis. This protein supplementation is mixed with glucose and electrolytes and is readily available from a variety of Sports drinks. It is also thought that athletes, who are starting on a new rigorous training programme, may benefit from protein supplementation. 5) What is creatine and how does creatine supplementation improve anaerobic power? 4 marks Creatine is a natural substance found in skeletal muscle, stored as phosphocreatine (PC). Creatine supplementation, together with a large amount of carbohydrate, is found to increase muscle uptake of creatine. Thus increasing PC levels to enhance the ATP-PC system. Increasing peak power production. And enabling the performer to train at higher intensities. By delaying the alactic/lactic threshold. Chapter 1 3

3 SECTION 3.1 CHAPTER 1 ANSWERS TO QUESTIONS 6) Briefly describe the process of carbohydrate degradation to re-create energy in the form of adenosine triphosphate (ATP) 12 marks Essay-style answer or equivalent diagram (figure Q1.1): 2 marks for: CHO is digested (broken down) to form glucose, and is transported to muscle cells for tissue respiration. The process of CHO degradation to re-create energy involves three stages within the muscle cell: 3 marks for three of: Stage one Glycolysis: Energy release takes place within the muscle cell sarcoplasm. Involving a process called glycolysis or the incomplete breakdown of glucose. Using glycolytic enzymes such as phosphofructokinase (PFK). Without oxygen being present. protein One molecule of glucose releases 2 molecules of ATP. And pyruvic acid. fats 3 marks for three of: Stage two - Kreb s cycle or the citric acid cycle: Occurs in the presence of oxygen. In the muscle cell mitochondria within the inner fluid filled matrix. Pyruvic combines oxaloacetic acid and acetyl CoA combine to form citric acid. To enter Kreb s cycle where pairs of hydrogen atoms are released. CO 2 is formed. 2ATPs are produced. 4 marks for four of: Stage three electron transport chain: Coenzymes transport hydrogen atoms (ions and electrons) into the electron transport chain. Within the inner part (cristae) of the muscle cell mitochondria. Hydrogen ions and electrons are charged with potential energy. Which is released in a step-by-step manner. As O 2 is delivered to react with the hydrogen ions and electrons. To create a large energy yield per mole of glucose (32/34 ATP molecules) and water. 1 molecule of glucose glycolysis pyruvic acid acetyl coa citric acid figure Q1.1 the aerobic system 7) Discuss the influence of dietary carbohydrates (CHO) and fats on muscle glycogen stores. 5 marks Carbohydrate and fats are the main fuel foods to provide the body s energy needs. Muscle glycogen depletion has been shown to be a major cause of fatigue. Studies have demonstrated that athletes who ate a high-cho diet for three days stored nearly twice their normal amounts of glycogen. And when they were asked to exercise to exhaustion. Their exercise performance significantly increased. But when a low-cho diet was consumed, muscle glycogen rapidly depleted. Reducing the exercise time to exhaustion. Showing that the secondary fuel food fat is unable to supplement reduced muscle and liver glycogen levels to the same level as carbohydrates. O 2 2ATP Kreb's cycle H+ ions and electrons H O 2 oxaloacetic acid lactic acid electron transpor t chain 2ATP CO 2 up to 32 ATP 4

4 SHORT-TERM PREPARATION 8) a) Discuss how a balanced diet could be manipulated to increase an athlete s glucose reserves prior to a marathon race. 6 marks Carboloading (or glycogen loading) before the event (modern method). This consists of tapering of training, whilst eating 50% CHO diet. Partially depletes glycogen stores. Therefore energy levels are not compromised. And glycogen synthase activity is increased. Then, gradually increase CHO intake to 70% of diet. With light training. Day of rest and 70% CHO diet. Repletes glycogen stores above normal level on day of marathon. Referred to as glycogen supercompensation. Taking in isotonic fluids during the event will top up blood glucose levels during the event. b) Carbohydrates are used as an energy source during both aerobic and anaerobic conditions. It is therefore beneficial that an elite athlete s stores of carbohydrate are at a maximum before competition day. Discuss the advantages and disadvantages of glycogen loading. 4 marks Advantages: Enhanced glycogen stores in muscle and liver. Overall effect is for overall times in aerobic activities beyond 90 minutes to improve significantly. Disadvantages: Increased body mass due to increased water retention. Needed for enhanced glycogen storage. During CHO depletion phase decreased energy levels. And increased fatigue (if using classic 10 day method of carboloading). c) How can an athlete s diet aid the recovery process? 2 marks Quick ingestion of carbohydrates and proteins (2 hour window of opportunity) will speed up recovery. Could be taken as a drinks supplement immediately following exercise or as a meal as soon as possible. Water needed to rehydrate the body. Electrolyte replenishment needed to aid metabolic process. Protein needed to aid tissue damage, repair and growth. 9) Describe how an athlete is able to control his or her body temperature during a marathon race. 4 marks Replace body fluids to prevent dehydration and over heating. Wear suitable clothing such as mesh running vest. That allows air to circulate. Hence body is cooled by evaporation of sweat, convection and radiation. Use sponge stations to cool down body parts. 10) What are the major avenues for loss of body heat energy? Which of these four pathways is important for controlling body temperature at rest, and during exercise? 4 marks for the major avenues: Radiation. Conduction. Convection. Evaporation. 1 mark for which of these four pathways is most important: Radiation is the primary method for discharging the resting body s excess heat. 1 mark for during exercise: Evaporation is the primary method for heat dissipation during exercise. 6 marks Chapter 1 5

5 SECTION 3.1 CHAPTER 1 ANSWERS TO QUESTIONS 11) Why is humidity an important factor when an athlete is performing in high temperatures? Why are wind and cloud cover important? 4 marks 2 marks for humidity: Water vapour in the air plays a major role in evaporative heat loss. Hence high humidity limits sweat evaporation and heat loss. 2 marks for wind and cloud cover: Wind increases heat loss by convection. Known as the windchill factor. Cloud cover reduces heat gain by solar radiation. 12) What is meant by heat acclimatisation? Outline the main physiological adaptations which occur to allow an athlete to acclimatise to training and competition in high temperatures? 8 marks 2 marks for heat acclimatisation: Refers to the physiological adaptive responses that improve heat tolerance. Repeated exercise in the heat causes a relatively fast physiological adjustment that enables an athlete to perform better in hot conditions: 6 marks for major physiological adaptations: Improves cutaneous blood flow: Transports metabolic heat from deep tissues to the body s shell. Lowers threshold for start of sweating: Hence evaporative cooling in the form sweating, particularly on exposed body parts such as arms and legs. Increased sweat output maximises evaporative cooling. Lowers sweat s salt concentration: Dilute sweat preserves electrolytes in extra cellular fluid. Cardiovascular functioning: Short-term physiological adjustments to cardiovascular functioning result in increased plasma volume. Thus supporting stroke volume. And allowing the body to maintain cardiac output. Giving greater stability in blood pressure during training and competition. Acclimatisation to hot, humid conditions: Results in increased sweating. Because high humidity contributes little to evaporative cooling. Combined effect of improved sweating and cardiovascular adaptations is to reduce core temperature and heart rate response. Therefore more training can be done before the onset of fatigue. And no adverse heat effects during a competition. 13) Describe the conditions at altitude that could limit performance. 3 marks Altitude causes hypobaric conditions or a reduction in barometric pressure. Resulting in decreased partial pressure of oxygen (po 2 ) throughout the body. Reducing the oxygenation of haemoglobin. Air temperature decreases as altitude increases. Solar radiation is more intense. Thus limiting human activity when compared with sea level performance. 6

6 SHORT-TERM PREPARATION 14) Describe the major physiological responses and adaptations that accompany acclimatisation to altitude over a period of three weeks. 10 marks 4 marks for four of immediate physiological responses: Pulmonary: Hyperventilation occurs immediately. As body fluids become more alkaline. Due to reduced CO 2 (H 2 CO 3 ) with hyperventilation. Corrected by the kidneys, which excretes a more alkaline urine solution. Cardiovascular: Increased submaximal heart rate. Increased submaximal cardiac output. Stroke volume remains the same or lowers slightly. Maximum cardiac output remains the same or lowers slightly. 6 marks for six of longer term physiological adaptations following 3 weeks of altitude training: Cardiovascular: Stroke volume lowers. Maximum cardiac output lowers. Decreased plasma volume. Increased haematocrit (the percentage of blood volume occupied by red blood cells). Increased haemoglobin concentration. Increased total number of red blood cells. Possible increased capillarisation of skeletal muscle. Cellular changes: Increased mitochondria. Increased oxidative enzymes such as pyruvic dehydrogenase. Net effect is to improve the aerobic working capacity of muscles to compensate for the reduced po 2. And to improve the capacity of the oxygen transport system. To purge the oxygen debt. 15) What is meant by the concept living high and training low? Identify two advantages of using this acclimatisation method. 6 marks 4 marks for four of: Living high and training low is an at-home acclimatisation method achieved at sea level. The athlete rests and sleeps in a hypobaric or hypoxic chamber. Created by a hypoxic generator that continually feeds altitude-stimulating hypoxic air into the tent. The hypoxic chamber provides an environment in which the athlete will gain the beneficial physiological adaptations expected from being exposed to hypobaric conditions. This is called living high. Training low refers to the athlete maintaining a sea level training environment. 2 marks for two of advantages: Less costly. Less disruptive to lifestyle, such as family relations. Maintains relationships and support systems such as quality training facilities, the personal coach, training group and medical team. Chapter 1 7