ANAEROBIC AND AEROBIC ENERGYSYSTEMSChapter 7Anatomy and Physiology for Coaches
Muscles Fibers need energy to sustain contraction 2 main sources of stored energy ATP (Adenosine Triphosphate) PCr (Phosphocreatine) When stored energy runs low, the body must produce more ATP Carbohydrate (glycogen) stored in muscle and liver Anaerobic glycolosis By-product is lactic acid Carbohydrate in blood Aerobic system
ANAEROBIC SYSTEM Non – oxidative (with out oxygen) Brief but intense Byproduct is Lactic Acid Important at the onset of exercise Important for events of short duration Low efficiency 1 glucose = 3ATP
LACTIC ACID By product of Anaerobic metabolism Change the acid-base balance in the muscle cell Reducing energy production by the aerobic system Causing burning sensation in muscles, nausea physical and mental fatigue Training reduces production of Lactic acid and improved the body’s ability to remove it from the system.
ANAEROBIC POWER Maximal all out effort for several seconds ATP-PCr energy system Nervous system sends a message to muscle cell ATP is split to ADP to release energy PCr restores ADP to ATP, thus repeating the cycle. Anaerobic glycolysis Break-down of glycogen with out oxygen. 3 ATP / 1 glucose Produces lactic aid
AEROBIC Uses oxygen to produce energy Abundant energy stores Carbohydrates 4 Kcal / gram Fat is abundant and rich energy source 9 Kcal / gram More efficient than anaerobic 1 glucose = 36 ATP Occurs in Mitochondria of the cell. Glucose + O2 = CO2 + H2O + energy* Protein is essential to build, maintain and repairissue, but is not a preferred energy source.
AEROBIC CAPACITY The ability of the aerobic system to take in, transport and utilize oxygen. a product of the respiratory, cardiovascular and muscular systems. Measured in L/min Higher measures indicate excellence in non-weight bearing sports.
AEROBIC POWER Aerobic capacity in relation to body weight Measured in ml/kg/min One’s ability to use oxygen per unit of body weight Predictor of performance in weight bearing activities
ANAEROBIC THRESHOLD Lactate threshold Transition zone that involves increase dependence on the anaerobic system. Upper limit of body’s ability to clear lactic acid. Lactate threshold 1 Easy training zone Uses primary slow oxidative muscle fibers Lactate threshold 2 fatigue occurs rapidly Performance threshold Both thresholds can be increased with training.
SPORT SPECIFIC TRAINING It is important to understand the demands of your sport Train to specifically meet the demands of your sport. Understanding specific energy demands helps to focus training for success.
ENERGY TRAINING Anaerobic For sports needing max effort or force production Sprinters and heavy lifters Uses stored ATP, CPr and Non-oxidative breakdown Events lasting up to 2 mins. Subtle changes seen with training Aerobic Training effects are clear Increase in mitochondria, increase enzyme activity, greater oxygen uptake, increase in fibers to produce ATP. Improvements in Cardiovascular and Respiratory systems. Improved ability to burn fat.
OTHER TRAINING EFFECTS Blood volume / stroke volume Amount of blood pumped per beat Aerobic training can increase blood volume Increase blood returned to the heart and pumped to the working muscle Slower resting and exercise heart rates Cardiac Output Volume of blood pumped per minute Cardiac output = heart rate x stroke volume Respiration Becomes more efficient with training Greater tidal volume less frequency is needed to meet the demands. Ventilation = tidal volume x frequency