P.E- Chapter 2- Energy Systems

• Carbohydrates are broken down into glucose, which is stored as glycogen in the muscles and liver.
• Glycogen provides ATP for both aerobic and anaerobic activity

Fats are the major source of energy for long term physical activity. Triglycerides or free fatty acids are consumed during ATP production

Protein contributes to ATP production minimally, usually only in extreme cases of malnutrition and exhaustion, when carbs and fat levels are low

• - Phosphocreatine system (ATP-PC)
• - Anaerobic glycolysis ( lactic acid system)
• - Aerobic glycolysis

• - used for short explosive efforts (1- 10 secs)
• -maximal effort activity
• - uses muscle stores of ATP and PC
• -energy created from splitting the phosphorous and creatine molecules is used to resynthesise ADP into ATP.

• - used during high intensity sub-maximal efforts (10- 60 secs)
• -uses body stores of glycogen and glucose (from muscles and liver)
• - glucose is burnt with out oxygen to create energy to resynthesise ADP to ATP
• -creates the by products pyruvic acid, which without oxygen will turn into lactic acid
• - 2 ATP molecules per molecule of glucose

• -basis for recovery process and extended sub-maximal efforts
• -uses body stores of glycogen and glucose (from muscles and liver)
• -glucose is burnt with oxygen to create energy to resynthesise ADP to ATP
• -due to abundance of oxygen a more complete breakdown of glucose occurs
• -oxygen breaks down pyruvic in citric acid cycle (+ ATP) and then electron transport chain (+ ATP). this happens in mitochondria
• - 38 ATP molecules per glucose molecule

• When substancial levels of oxygen are available lactic acid is
• - converted into pyruvic acid
• -oxidised in mitochondria via citric cycle and electron transfer chain (creates ATP for muscles)