TOPIC: TRAINING ADAPTATIONS

Transcription

1 TOPIC: TRAINING ADAPTATIONS SECTION A Multiple-choice questions Choose the response that is correct or that best answers the question. A correct answer scores 1, an incorrect answer scores & marks will not be deducted for incorrect answers. No marks will be given if more than one answer is completed for any question. Question 1. Glycolytic capacity is increased with anaerobic training due to: A. Increased glycolytic enzymes (ANS) B. Decreased glycogen stores C. Increased oxidative enzymes D. Decreased myoglobin stores Question 2. A middle distance runner undertakes 12 months of aerobic training in an effort to break into the senior athletics team as a 5,000m runner. Compared to 12 months ago, he would now have : A. Increased oxidative enzymes at leg muscles (ANS) B. Increased energy usage at each stage of the race C. Decreased oxygen phosphorylase at slow twitch fibres D. Decreased reliance upon the anaerobic glycolysis system Question 3. Three friends went on a fishing trip a weight lifter, a triathlete and an accountant. Unfortunately their boat capsized and they perished. When their bodies were recovered autopsies were conducted and their hearts compared: In order from left to right the hearts belonged to: A. triathlete : weight lifter : accountant B. accountant : weight lifter : triathlete C. triathlete : accountant : weight lifter D. weight lifter : accountant : triathlete (ANS) Question 4. For an untrained athlete, which of the following is a chronic response to the short-interval training program shown below?

2 Distance Intensity Rest Sets 15m 95% max HR 90 seconds 4 A. Decreased resting heart rate B. Improved glycogen sparing C. Increased contractile force (ANS) D. Decreased diastolic blood pressure Question 5. The following is an example of a chronic respiratory training adaptation likely to occur in response to aerobic training: A. Reduced resting heart rate B. Reduced oxygen consumption by respiratory muscles when working sub-maximally (ANS) C. Reduced levels of LDL D. Increased cardiac output Question 6. Continuous training undertaken in preparation for the 20km walk will result in the following adaptations at the muscular level: A. Increased oxygen force capacity (OFC) B. Increased antioxidative enzymes C. Increased contraction speed D. Increased mitochondria density (ANS) Question 7. As a result of aerobic adaptations to continuous training, at maximal workloads, the increased cardiac output increases: A. Myocardial contractility B. Plasma preservation C. Aerobic glycolysis (ANS) D. Blood flow to major organs Question 8. At slow twitch fibres, the following is likely to occur as a result of the following long interval training sessions: Distance Intensity Rest Sets 1600m 75% max HR 6 mins 4 A. Increased haemoglobin B. Decreased fat oxidation C. Increased intramuscular triglycerides (ANS) D. Decreased glycolytic enzymes

3 SECTION B Short answer questions Question 1. Cadel Evans is a brilliant Australian and International cyclist who has performed very well in the Tour de France in the last 3 years and finished top 3 after riding a gruelling 21 days and over 1000 kilometers. a. Most of Cadel s training is of an aerobic nature and conducted between 80-85% max HR for periods in excess of 2-3 hours at a time. He also focuses on his sprint cycling in order to replicate this during race stages. Discuss how increased ATPase resulting from this sprint training leads to improved performances. ATPase facilitates the breakdown of ATP to ADP. Anaerobic training increases the quantity and the activity of these enzymes which increases the turnover of ATP (breakdown and resynthesis). All of this allows for a more rapid release of energy for Cadel and contributes to quicker / more forceful contractions. b. Clearly discuss how Cadel s VO 2 max of 84 ml/kg/min has contributed to his high finishing place in the Tour de France. A high VO2max would assist Cadel by enabling his cardio-respiratory systems to supply large amounts of oxygen to his working muscles with great efficiently. His muscles also have an increased ability to utilise oxygen, and therefore the production of aerobic ATP / energy. All of this will also allow him to work at higher intensities before needing to slow down if lactate and H+ start to accumulate. c. Clearly discuss the effect sprint training has on motor unit recruitment. Sprint training enhances motor-unit recruitment. The greater the number of motor units that can be recruited, the greater the force that can be developed in the muscle. Maximal force requires the recruitment of as many motor units as possible. As well as recruiting more motor units, there is an increase in the ability to recruit high-threshold motor units which are typically fast-twitch fibres. With sprint training, there is an increase in the recruitment of fast-twitch fibres and in the time for which the contraction can be maintained. These adaptations result in increased force production, rate of force development (power) and length of time for which the contraction can be maintained. Question 2. Two athletes undertake the same high intensity interval training program (above 85% HR max) over a 16 week period. Athlete A is an endurance athlete while athlete B is a sprinter. Both train three times per week. a. What benefit would athlete A be hoping to gain from this high-intensity interval training? High intensity training above the lactate threshold benefits both the anaerobic and aerobic athlete by : Increasing our VO2 max; expanding the capillary network; Increasing muscle enzyme activity; increasing our tolerance of lactic acid; training our muscles to remove lactic acid more quickly; increasing the lactate threshold so that lactic acid accumulates later in exercise b. How long would athlete B need to continue training before any appreciable gains were evident?

4 Anaerobic fitness gains are not usually evident until after weeks of training c. State two chronic changes to athlete B s cardio-respiratory system and one change in the muscle fibres that would be evident, at rest, at the completion of the training program. Cardio-respiratory change 1: Cardio-respiratory change 2: Cardio-respiratory changes at rest include: cardiac hypertrophy; decreased residual volume; increased inspiratory reserve volume; increased vital capacity; increased haemoglobin; increased blood volume; increased redistribution of blood; increased a-vo2 difference; increased capillary density; increased muscular hypertrophy (possibly); increased muscular stores of ATP & PC; increased ATP-PC splitting; increased resythensis of enzymes; increased glycolytic capacity; increased actin & myosin size; decreased blood cholesterol (particularly LDL); increased HDL; decreased blood pressure. Muscle fibre change: PC stores glycolytic enzymes myosin ATPase ATP stores glycogen stores contractile proteins muscle buffering capacity / by-product tolerance Question 3. Jay is an up and coming rower who has just been selected to represent Australia at the next junior world games. At time of selection Jay was a standout and rowed 4725 metres in 20 minutes with an average heart rate of 148 bpm. After six months training with the representative squad Jay could row 5236 metres in the same time with an average heart rate of 145 bpm. a. List two chronic cardiovascular adaptations Jay is likely to have experienced during his training which would explain improved performance. Explain how these changes contribute to improved performance. Cardiovascular adaptation 1: How it would improve performance Cardiovascular adaptation 2: How it would improve performance Answers must only focus on cardiovascular parameters, i.e nothing related to respiratory or muscular adaptations would be acceptable answers. Any two of the following could be listed cardiac hypertrophy ( ventricle volume rather than ventricle thickness although thickness would contribute to increased cardiac contractility and greater emptying with each systole)

5 increased stroke volume/cardiac output increased capillarisation (to heart and muscles) increased blood volume ( including plasma/haemoglobin) Cardiovascular adaptations would improve performance because they lead to an increase in oxygen delivery (uptake is related to respiratory adaptations and thus would not be relevant in answers) to working muscles, making more oxygen available for energy production. Answers could also state the changes increase the body s ability to produce aerobic energy/atp and decrease involvement on the anaerobic glycolysis system which has associated fatigue factors caused by accumulation of metabolic byproducts. Increasing the number of capillaries around the muscle leads to an increase in the supply of oxygen and other nutrients and enhanced removal of waste products from the muscle. Greater plasma volumes would enable Jay to dissipate heat produced from energy production more quickly making it less detrimental to performance. b. The following graph shows Jay s lactate responses to incremental rowing on an ergo with the stroke rate increased x 4 every two minutes. i. Which Line, A or B, represents Jay s rowing after 6 months of training? Ans = A ii. At the muscular level, discuss one adaptation that would account for Jay s lactate training response changes. Responses would focus on slow twitch fibre adaptations and how they contribute to improved performances in terms of delaying lactate accumulation / or increasing LIP. Increased mitochondria size, number and surface area, enhancing the capacity of the fibres to produce energy (ATP) aerobically, and less likely to trigger LIP when lactate accumulates. Increased mitochondria and oxidative enzymes that allow work at higher percentages of their VO2 max without accumulating blood lactate.

6 Increased ability of the slow twitch fibres to oxidise glycogen (aerobic glycolysis) with less reliance upon anaerobic glycolysis. Greater utilisation of FFA (working submaximally), therefore less lactate is produced. c. Discuss one respiratory adaptation that is likely to have occurred for Jay as a result of 6 months continuous training and how this would contribute to improved performances. It is important that discussion on how the respiratory change would contribute to improved performances is incorporated in the answer. e.g. Increased tidal volume leading to less breaths to supply same/more oxygen at sub-maximal intensities means more oxygen is available for working muscles. At maximal levels tidal volume increases which produces higher ventilation and VO2.Increased alveolar-capillary surface area and hence increased diffusion of gases at the lungs and uptake of oxygen to then be transported to working muscles. Increased efficiency of the intercostals muscles making more oxygen available to be supplied to working muscles. Question 4. a. What happens to the arteriovenous oxygen difference (a-vo2 diff) at maximal intensities in response to 9 months of Fartlek training? It increases b. Discuss two factors that contribute to the response you have identified in (a) above. Increased capillarisation of the muscle fibres (essentially slow twitch) which leads to an increase in the diffusion of oxygen, carbon dioxide and other metabolic by-products. Increased diffusion and blood distribution to the working muscles which increases oxygen supply/concentration to working muscles Increased capacity of the muscles to extract and process oxygen via increased mitochondria and oxidative enzymes, leads to an increase in the a-vo2 diff c. State a situation that would lead to the a-vo2 diff decreasing. Answers could range from something as simple as decreasing the intensity / workload which would see decreased demand for oxygen by working muscles to other more complex scenarios such as: Detraining as a result of injury or long term training lapses Working at high (2000+m) altitudes Being winded during activity (reduced diaphragm and intercostal function)

7 Oxygen Consumption (ml/kg/min) Question 5. Oxygen Consumption experienced by a triathlete and a 100m sprinter running on treadmills at varied speeds for 10 minutes A B Exercise Time (mins) a. Which line, A or B, would represent the triathlete? B = triathlete b. Briefly justify your selection in (a.) above. B has lower heart rates at each stage of the test and experiences steady state from 5 /6 min mark which is quicker than B indicating quicker activation of their better developed aerobic energy system. From the 5 /6 min mark B s oxygen consumption steadily increases indicating they are struggling to meet demand. c. The triathlete is likely to have increased the amount of alveoli in her lungs as a result of aerobic training adaptations. How does this lead to better performances in the triathlon? Increased alveoli would lead to increased alveolar-capillary surface area and hence increased diffusion of gases at the lungs. This allows more oxygen to be taken up (inhaled) and more carbon dioxide to be given off (exhaled). Question 6.

8 Muscle Fibre Area (um) Adaptations in quadricep muscle group following training Pre Post Slow Twitch Muscle Fibre type Fast Twitch The above graph shows the changes in the composition of the quadriceps muscles for a 15 year old male following 3 months of training/participation in activities aimed at increasing his muscular strength and reducing his percentage body fat. a. Outline the type of activity/training that he is likely to have participated in, and justify your answer by using the data contained in the graph. The post test results indicate greater increases in the fibre diameter of fast twitch fibres, even though slow twitch fibres have shown a lesser increase in diameter. It is most likely that the boys were involved in anaerobic training methods such as short/intermediate interval; weight training; high intensity circuit training or plyometrics. b. (i) Other than increased fibre size, list three other chronic adaptations likely to have occurred at the quadriceps fast twitch fibres Students cannot select increased fibre size or cross sectional area. number (hyperplasia) PC stores glycolytic enzymes myosin ATPase improved motor unit recruitment speed of contraction size of connective tissue / tendons recovery times ATP stores glycogen stores contractile proteins muscle buffering capacity / by-product tolerance neural transmission force of contraction LA production (sub-max)

9 (ii) Select one of the above changes and clearly discuss how this would lead to improved performance. Improves performance by number (hyperplasia) PC stores glycolytic enzymes myosin ATPase improved motor unit recruitment speed of contraction size of connective tissue / tendons recovery times Whilst yet to be widely accepted, more fibres would result in greater forces being produced. More readily available fuel for explosive / maximal contractions and delays peak contribution from LA system Greater ability to release ATP from both muscle and stored glycogen Greater amount of cross-bridge formation and generation of force More fibres able to be recruited per contraction resulting in more force being produced Greater force possible Greater attachment to bones and thus greater forces can be applied, less likelihood of in jury at this site Fibres able to resynthesise PC at a quicker rate and thus have this able to be re-used for other contractions ATP stores Less reliance on PC (initially) and greater explosive ability for first 2-3 seconds of an activity glycogen stores contractile proteins muscle buffering capacity / byproduct tolerance neural transmission force of contraction LA production (sub-max) Less reliance on glycogen being transported from liver and more readily available when stored at the muscle site itself. Less likelihood of using FFA s and associated drop in ATP production rate. Able to generate greater forces and resultant muscular power Improved LA tolerance and ability to sustain contractions in the face of accumulating H+ ions Improved reaction to stimuli More power can be generated with greater associated speed of movement Delays LIP and accumulation of hydrogen ions and thus delays resultant fatigue

10 Question 7.Tien returns to training after a 12-week lay-off due to an achilles tendon injury. She finds that she needs an extra minute to recover between her repeat 300m sprints as part of her intermediate interval training. Distance Work Rest Sets period period Pre-injury 300m 50 seconds 4 minutes 4 Post-injury 300m 50 seconds 5 minutes 4 a. State two physiological changes that may have occurred during this period of detraining. decreased LIP decreased lactate tolerance reduced ability to buffer/oxidise lactate during efforts, results in increased lactate accumulation reduced aerobic capacity (decreased mitochondria, myoglobin, oxidative enzymes) b. Discuss how the change listed in part a. has caused the need for an increased one minute recovery between 300 m efforts. More time is needed to remove lactate between efforts. Lactate accumulation will occur at lower intensities and earlier in the 300m sprints. Reduced aerobic capacity also affects the ability to restore ATP- PC stores between efforts. Reduced aerobic capacity will result in greater reliance on the anaerobic energy system and therefore increase the production of lactate.