Physiology of Athletes

Physiology of Athletes Extended Response 1 This is fun run is effective as it incorporates factors affecting performance.   The two competitors which participated in the long distance (14km) fun run must have used the dominant energy system which is the Aerobic Energy System even though in the certain parts of the event the ATP energy system could have been used.   The aerobic system is initiated during continuous activity and the body is then able to provide oxygen to the working muscles. The presence of oxygen allows the muscle glycogen to be broken down to form ATP, this overall process is the aerobic glycolysis. The sources of fuel for the aerobic system are carbohydrates which are broken down into glucose are either used or stored as muscle glycogen and/or the liver, fat can also be used over long periods once the glycogen fuels deplete. Compared to the ATP/PC system the production of ATP for the Aerobic System is the slowest but the most efficient , it utilises oxygen to metabolise muscle and liver glycogen as well as blood glucose and fatty acids. The duration is technically unlimited depending on the intensity and availability of oxygen, the cause of fatigue is the continuous use and depletion   of blood glucose, muscle glycogen, or fatty acids. The by-products of energy production in the aerobic energy system is water, carbon dioxide (CO2) and heat. The aerobic system takes the longest time to recovery and depending on the intensity of the activity it takes approximately 24 hours to replenish the energy stores. The two athletes must have had different physiological adaptations due to the huge difference in times as the faster athlete finished in 48 min while the slower athlete finished in 85 min. These adaptations include resting heart rate which is the minimum number of heart beats required to maintain body function at rest, in response to training the resting heart rate decreases as aerobic fitness improves because of the increased efficiency of the cardio respiratory system   meaning the heart does not need to work as hard. Other adaptations include stroke volume and cardiac output which refer to the amount of blood pumped via the left ventricle in each contraction and the amount of blood pumped each minute , in response to training the heart size will increase especially the ventricles making it possible for more powerful contractions and more blood to be discharged every contraction. A high intensity activity will need more blood meaning higher stroke volume, this is one of the factors that clarify why the competitor finished faster than the other as the trained athlete has a higher stroke volume compared to an untrained athlete.   The cardiac output also becomes more efficient as the heart rate adjusts to the body meeting the blood demands, it is proportional to stroke volume. Oxygen uptake and lung capacity are physiological adaptations, oxygen uptake (VO2 max) is the absorption and utilisation of oxygen by muscles at certain intensity, lung capacity is the amount of air that can be held within the lungs during a breadth. In response to training vital capacity increases slightly while the residual volume slightly decreases, but the total lung capacity does not change unless maximal effort activities are undertaken. Haemoglobin level is the amount of red blood cells (oxygen carriers) this is also a physiological adaptation, in response to training the haemoglobin level increases meaning the red blood cells can carry more oxygen making the athlete perform high intensity activities. Due to training another physiological adaptation that can occur is the reduction of blood pressure in the body due to the result of extensive training, blood pressure is the term used to describe the pressure of blood in the inner artery walls. Looking at all the stated physiological adaptations by the help of aerobic exercise it is clear that the faster athlete has trained extensively using a proper training program, by doing so this athletes long term body response due to the training is enhancing his ability in completing the 14km fun run faster than the slower athlete. Extended Response 2 Athletes using supplementation is often debated on the basis of how effective it is. The reason why athletes use supplements is to help the athlete achieve their nutritional needs and goals especially during competition and training. The main supplements used by athletes include vitamins, minerals, caffeine, protein supplements and creatine supplements. The point of taking vitamin supplements is to help the body release energy from food, the energy that is released is then incorporated in tissue rebuilding and metabolic regulation. The advantage of taking vitamins is that through taking antioxidants (vitamin C, E and beta-carotene) it can de-stress the athletes. The disadvantage is that if an athlete takes vitamins in high dosage it could have detrimental effects (excessive consumption if vitamin A can cause fatigue, loss of appetite, nausea and skin dryness) and in general it does not affect performance. Vitamins do not affect sports directly. By taking mineral supplements performance is maintained as the body function is regulated. The consumption of iron supplements reduce the effects of sports anaemia and the use of calcium maintains the quality of bones. Minerals are mostly used in sports to make sure the athlete performs at their peak. Protein is the supplement responsible for growth, repair and maintenance of body tissue and in most cases while performing extreme level activity can act as a energy source. Protein can repair deficient muscles, but in excess use it can contain carcinogenic additives while protein seen to be very useful it has not directly related to sport. Caffeine is an ergogenic aid which has a positive impact on metabolic processes and it is also affects the aerobic/anaerobic performance due it being a stimulant having an effect on the cognitive processes helping the alertness of an athlete. Caffeine is helpful for endurance athletes (marathon runners) due to the free fatty acids which are used on working muscles converted from fat stores and it also advocates glycogen sparing. Working muscles that use ATP-PC can derive energy through creatine supplementation. Creatine supplements helps an athlete achieve muscle hypertrophy and improves ATP resynthesis and recovery time, but if overdosed the chances of contracting renal disease and getting muscle cramps increases. Creatine supplements focuses on weightlifters and also sprinters as with it use gives explosive movements. There is a lot of evidence pursuing for the use of supplements for improved performance. This evidence includes that it can help specific athletes either who are vegetarians that lack calcium or iron in their diets or females to prevent osteoporosis later in life they may need the consumption of more calcium meeting their nutritional goals having an indirect performance enhancement. Direct performance enhancement can be achieved through the correct use of supplements, caffeine assists in fat metabolism in endurance events and improves cognitive processes, protein can be taken by strength athletes and endurance athletes due to the intensity of the activity, creatine easily allows muscle hypertrophy to be achieved and it also improves the recovery time and ATP resynthesis. Another piece of evidence is that it provide the athlete with a psychological boost improving performance (placebo effect). The use of supplements can also meet the nutritional goals of an athlete such who has defici encies (mineral/vitamin), the difference in food when travelling to a different country and not being able to maintain normal eating schedule. There is also a lot of evidence voting against the use of supplements for improved performance. Evidence includes that it may have side effects through excessive use; vitamins can cause joint and muscle pain, nausea, headaches ; creatine can cause increase chance of renal disease and muscle cramps; protein is a contributor to obesity due to the unused protein being stored as fat and can also cause renal problems. Other side effects that have an effect on performance is when consuming creatine it can cause unnecessary weight-gain creating a problem for weight based sports e.g. boxing, protein can contain carcinogenic additives and caffeine can cause a diuretic effect increasing the rate of dehydration. Another piece of evidence against supplementation is that if the body is in excess the expensive capsules/powders consumed are excreted. Creatine also cause contamination as it may contain banned substances (banned by anti-doping agencies). With the constant use of supplements the costs focused on training, equipment and diet needs shifts to the supplements causing a finance problem. For an elite sports athlete having a balanced with adequate amounts of protein, a natural source of creatine and eating foods that contain what the supplements contain sufficiently   makes the use of supplementation unnecessary however if due to certain circumstances cannot keep to the balanced diet they may turn to supplements as a short-term assistor.