5. Energy Systems.docx

Energy Systems: Energy is needed to produce physical movement, maintain body temperature and to keep up all the metabolic activities of the body. In our bodies, all physical movement relies on a compound called Adenosine Triphosphate (ATP). ATP is stored in muscles so it is readily available for mo...

Energy Systems: Energy is needed to produce physical movement, maintain body temperature and to keep up all the metabolic activities of the body. In our bodies, all physical movement relies on a compound called Adenosine Triphosphate (ATP). ATP is stored in muscles so it is readily available for movement, however it is limited in source. So any movement that lasts longer than a few seconds required more ATP to be produced. Our bodies have 3 systems that can produce ATP: ATP-CP system, Glycolytic system (Lactic system) and the Oxidative (Aerobic) system. The ATP-CP and Glycolytic systems are Anaerobic systems i.e do not require oxygen for energy production where as the Oxidative system is an Aerobic system. 1. ATP- CP: - ATP-CP system is based upon movements lasting 5-15 seconds that require strength and power such as jumping, throwing, golf swing, racket serve etc. - ATP stored in muscles provide a short burst of energy required using a compound called creatine phosphate (CP) which buffers the ATP for a few more seconds. Like ATP, CP is also limited in source and therefore cannot sustain in movements of a longer duration. 2. Glycolytic System: - This system relies on the rapid breakdown of carbohydrates to produce ATP. - Glucose, which is a very common form of carbohydrate is constantly circulating in the bloodstream and Glycogen (stored form of glucose) is stored in the muscle and liver. - The blood sugar is broken down to produce ATP through a process called glycolysis. - In this process, a substance called lactate is formed and hydrogen ions are released. It is believed that the accumulation of these hydrogen ions in the muscles make it acidic contributing to fatigue and burn. - This system produces energy very quickly and helps in movements that last 1-2 minutes (sprints) but not over a long duration. 3. Oxidative System: Oxidative system uses oxygen through two metabolic processes, Kerbs cycle (citric acid cycle) and electron transport chain to produce ATP. This system, with all of it sources, cannot produce ATP nearly as quickly as the 1^st^ two but produces for a long duration of time. It uses carbs, fats, if required then even protein. However, fats and protein take longer to breakdown. This system is used for longer duration activities such as running a marathon. Heart Rate Zones: During exercise, a greater demand is placed on the entire cardiovascular system. This is in response to the working muscles requiring more oxygen & nutrients for energy production. In an average human, the resting heart rate (RHR) averages anywhere between 60-80 beats per minute (BPM). During exercise, the heart rate (HR) increases according to the intensity of the exercise & will continue to rise until the demands for nutrients & oxygen are met. As the heart rate continues to rise, it rises through 5 different heart rate zones, each causing a different response within the body. Heart Rate Zone \% of HR Max Duration Response/ Benefits ----------------- -------------- ----------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Zone 1 50-60 % 20-40 min Warm up / Recovery; this is a very low intensity zone. Training at this intensity will either boost your recovery in a cool down or get you ready to train in the higher heart rate zones as part of a warm up. Zone 2 60-70 % 40-80 min Base fitness level; this is your fat burning zone. At this intensity the body is breaking down (burning) fat for energy; which is good for weight loss. This zone also improves endurance to be able to perform at higher intensities. Zone 3 70-80 % 10-40 min Aerobic Capacity; the body uses oxygen to produce & regenerate energy (ATP). This zone great for improving aerobic fitness, improves efficiency in blood circulation in the heart & skeletal muscles.  During this zone energy consumption is split equally between carbohydrates & fats. Zone 4 80-90 % 2-10 min Anaerobic Capacity; this where the going gets tough & you are able achieve maximum calorie burn. This effort can only be sustained for short periods of time. This zone improves your overall performance as well as increasing your lactate & aerobic thresholds. Zone 5 90-100 % Less than 5 min Maximum Capacity; this is the highest heart rate zone & is the maximum effort in any form of exercise. This intensity level can only be sustained for about a minute at time.