Energy Systems 3 Systems 3 groups of energy nutrients Muscle fibre types

Three Energy Systems ATP – PC (anaerobic alactic) – No oxygen ATP – PC (anaerobic alactic) – No oxygen Glycolysis (anaerobic lactic) – No oxygen Glycolysis (anaerobic lactic) – No oxygen Aerobic System – oxygen needed Aerobic System – oxygen needed

Adenosine Triphosphate (ATP) ATP – It is re-synthesized in two ways: ATP – It is re-synthesized in two ways: Aerobically in the mitochondria = 36 ATP Aerobically in the mitochondria = 36 ATPor Anaerobically in the cytoplasm = 1or 2ATP 1 molecule of PC gives 1 molecule of ATP 1 molecule of PC gives 1 molecule of ATP 1 molecule of glucose gives 2 ATP + Lactate 1 molecule of glucose gives 2 ATP + Lactate

The Three Energy Nutrients Carbohydrates – glucose and glycogen Carbohydrates – glucose and glycogen Proteins – amino acids Proteins – amino acids Fats – fatty acids Fats – fatty acids

ATP – PC system Anaerobic alactic – no lactic acid is produced Anaerobic alactic – no lactic acid is produced Lasts seconds Lasts seconds Uses stored ATP and creatine phosphate Uses stored ATP and creatine phosphate No by-products, just the product ATP No by-products, just the product ATP

Glycolysis Anaerobic Lactic system Anaerobic Lactic system Lasts 15 seconds – 3 minutes Lasts 15 seconds – 3 minutes Uses glucose and glycogen to make ATP Uses glucose and glycogen to make ATP By – product is lactic acid By – product is lactic acid

Aerobic System Occurs in cytoplasm and mitochondria Occurs in cytoplasm and mitochondria Needs oxygen to produce all 36 ATP Needs oxygen to produce all 36 ATP Lasts as long as you are alive Lasts as long as you are alive Uses glucose, glycogen, fats, and proteins to make ATP Uses glucose, glycogen, fats, and proteins to make ATP By-products are carbon dioxide and water By-products are carbon dioxide and water

Muscle Fibre types Type I – slow twitch (aerobic) Type I – slow twitch (aerobic) Type IIA – Fast twitch ( Fast twitch oxidative or FOG) Type IIA – Fast twitch ( Fast twitch oxidative or FOG) Type IIB – Fast twitch (anaerobic) Type IIB – Fast twitch (anaerobic)

Type I Slow contractions but can go a long time Slow contractions but can go a long time Red (dark) in colour Red (dark) in colour Predominantly used in aerobic activities Predominantly used in aerobic activities High concentration of myoglobin – muscle can store oxygen for regeneration of ATP High concentration of myoglobin – muscle can store oxygen for regeneration of ATP

Type II A In between fast and slow twitch In between fast and slow twitch Faster, stronger contraction than Type I but can be sustained longer than Type IIB Faster, stronger contraction than Type I but can be sustained longer than Type IIB Redish/white in colour Redish/white in colour Moderate myoglobin concentration Moderate myoglobin concentration Predominantly used in anaerobic activities Predominantly used in anaerobic activities

Type II B Fast twitch Fast twitch White in colour White in colour Fastest contraction speed of all muscle fibres Fastest contraction speed of all muscle fibres Low myoglobin concentrations Low myoglobin concentrations Predominantly used in anaerobic alactic activities – explosive lift or jump Predominantly used in anaerobic alactic activities – explosive lift or jump

Approximate Distribution of muscle fibre types Sport % slow twitch % fast twitch Cycling6139 Middle – distance runner 5941 Sprinter2674 Untrained person 4258