Chapter 5: How does training affect performance?
Energy systems * alactacid system (ATP/PC) * lactic acid system * aerobic system
Energy Systems * The human body requires energy for its organs to function, internal processes to take place and to power muscular contractions for movement * Energy in the human body is stored in the chemical bonds that join atoms and is released when needed * The transformation of food, chemical energy, into energy that the muscles can use, mechanical energy, is the role of energy systems * Chemical energy is energy stored in bonds between atoms * Mechanical energy is motion or movement energy * Energy provided by food is measured in kilojoules (kJ) * Adenosine triphosphate (ATP) is a high energy compound that stores and transfers energy to body cells * The ATP compound consists of a large molecule call adenosine and three smaller molecules called phosphate, each phosphate is held together by high energy bonds * When the last or terminal phosphate is detached, the energy stored in this bond becomes available and is transferred to the cells * Energy from ATP allows the fibres in muscles to contract, enabling movement * Once the phosphate molecule has detached it is referred to as Adenosine diphosphate * Resynthesis is the process of restoring ATP to its former state
The three systems that make ATP available are: * The alactacid system (ATP/PC) * The lactic acid system (glycolytic system) * The aerobic system (oxygen system)
* The alactacid and lactic acid systems are anaerobic pathways as they do not use oxygen for the resynthensis of ATP * The aerobic system uses oxygen for the resynthesis of ATP and is oxygen dependent * Although the energy systems are examined in isolation, they function together, the predominant energy system is the one being most utilised at that point in time
Alactacid system