Muscle Contraction Learning Objectives To know the different

Muscle Contraction

Learning Objectives • To know the different muscle fibre types. • To understand the structural and functional characteristics of the different muscle fibre types. • To be able to justify different muscle fibre types in different sports performers.

Slow twitch (Type 1) Fast oxidative glycolytic (Type 2 a/ FOG) Fast Glycolytic (Type 2 b/ FG)

Muscle Fibre Types Characteristics Slow Twitch (Type 1) Fast Oxidative Fast Glycolytic (Type 2 a/ (Type 2 b/ FG) FOG) Small Large Moderate High Low Highest Slow Fastest Lowest Myoglobin - a protein found in the muscle cells of animals. It Number of mitochondria functions as an oxygen-storage Number of capillaries unit, providing oxygen to the working muscles. Myoglobin content PC - One of the ways that this PC stores ATP supply is regenerated is Glycogen stores through the molecule creatine Triglyceride stores phosphate (or phosphocreatine). Speed of contraction Glycogen - a multi-branched polysaccharide of glucose that Force of contraction serves as a form of energy storage Resistance to fatigue in animals. Triglyceride - Fat and Fibre size Aerobic capacity Anaerobic capacity carbohydrate storage within muscle fibres are called intramusculartriglycerides.

Characteristics Fibre size Number of mitochondria Number of capillaries Myoglobin content PC stores Glycogen stores Triglyceride stores Speed of contraction Force of contraction Resistance to fatigue Aerobic capacity Anaerobic capacity Slow Twitch (Type 1) MARATHON Fast Oxidative Glycolytic (Type 2 a/ FOG) 800 M Fast Glycolytic (Type 2 b/ FG) SPRINT HURDLES

Muscle Fibre Types TASK Cut out/ print out pictures of different types of performers. Stick them in and under each picture make a prediction of the relative percentages of the three types of muscle fibre in specific skeletal muscles. Justify your answer by using your knowledge of the structural and functional characteristics of muscle fibres. Athlete Gender Muscle Slow Twitch % Fast Twitch % Sprinters M Gastrocnemius 24% 76% 27% 73% 79% 21% 69% 31% F Distance runners M F Gastrocnemius