Characteristics of the Three Energy Systems.

Characteristics ATP-PC Energy System Anaerobic Glycolysis Aerobic Energy System Energy System Alternative Name/s Phosphagen system Lactic Acid system Oxygen system ATP-CP system Lactacid system Creatine phosphate system Phosphate system Aerobic or Anaerobic Anaerobic Anaerobic Aerobic

Fuel/s Used  Phosphocreatine (PC)  Carbohydrates which  Carbohydrates- preferred also known as creatine are stored as glycogen fuel during exercise. phosphate which is stored within the muscles cells  Fats- stored as triglycerides in in small quantities within and the liver. muscle cells and the liver. muscle cells. Used predominantly when body at rest and during lower intensity exercise (up to about 50-65% of maximum oxygen uptake).  Proteins- only in extreme circumstances such as starvation or ultra endurance events. Maximal Rate of  Fastest rate of energy  Provides energy for ATP  Slowest system to provide Energy Production release for resynthesis of resynthesis rapidly, but energy for ATP resynthesis ATP from ADP and Pi. not as quickly as the due to complex nature of its  3.6 mols per minute ATP-PC system. chemical reactions, and the  This is because this system  1.6 mols per minute. fact that sufficient oxygen has is the least complicated of  This is due to a more to be made available to the the three energy systems complex series of muscle cells. (fewer chemical steps) and chemical reactions which  1.0 mol per minute. because PC is found within results in glycogen the muscle cells breaking down to glucose themselves. and then to pyruvic acid and then eventually to lactic acid. Maximum ATP  Small amounts of ATP  Approximately twice as  Vastly greater amounts of Production (Yield) per produced. much ATP produced as ATP produced as compared mole of fuel source  Less than one mole of ATP the ATP-PC system. to the two anaerobic systems. per mole of  Approximately 2 mols of  38 mols of ATP from one mol phosphocreatine. ATP per mol of glycogen. of glycogen.  Over 100 mols of ATP from one mol of fat (but more oxygen required). Duration and Intensity  Activated at the beginning  Also activated at the  Also activated at the start of of Peak Energy of high intensity exercise. beginning of high high intensity exercise and will Production  Predominant energy intensity activity. become the predominant supplier within the first 5  Predominant energy supplier of energy for ATP seconds of high intensity contributor for ATP resynthesis during continuous exercise, but its capacity is resynthesis from the time sub-maximal intensity depleted after 5-15 when the phosphagen exercise which exceeds 1-2 seconds of maximal system is rapidly minutes in duration. intensity exercise. depleting up until about  In a maximal effort lasting 75 30-75 second during high seconds, equal energy is intensity exercise. derived from the aerobic and  May also become anaerobic systems. predominant producer of  Predominant supplier of energy for ATP energy for ATP resynthesis resynthesis during when at rest and during sub- repeated short duration maximal activity. maximal intensity efforts  As every duration increases which have insufficient and intensity decreases, the recovery time to allow for contribution of the aerobic full replenishment of system to energy production phosphocreatine stores. increases whilst that of the anaerobic systems diminishes. Specific Examples  Athletic field events (eg.  200 and 400 metre  10 000 m athletic event. high jump, shot put) athletic events.  Marathon  Short sprints  50 metre swim.  2000 m rowing event.  Tennis serve  High intensity tennis rally Mid field players in many team  Gymnastics vault of 15-20 seconds sports (eg. Australian Rules,  Golf drive duration. Soccer). Major Limiting  Depletion of  Changes in the intra-  Accumulation of lactate and Factor/s (when phosphocreatine stores muscular environment hydrogen ions. functioning associated with (but not  Depletion of glycogen stores. maximally) necessarily caused by) an increase in lactate and hydrogen ions (H+). Metabolic By-  Nil  Lactic acid- lactate and  Carbon dioxide (CO2) Products Produced hydrogen ions (H+).  Water

Links to fitness  Muscular strength  Anaerobic power  Relevant to all fitness components  Muscular power  Local muscular components because it  Anaerobic power endurance provides the basis for  Speed  Speed recovery in anaerobic type  Agility  Muscular power tasks (strength, power, speed,  Reaction time etc) or the bulk of energy production for sub-maximal activities.