Sports science

• Compact bone has a hard outer layer that provides strength and protection, while spongy bone has a soft inner layer with many small spaces filled with red marrow where blood cells are produced.
• There are two types of bones: long bones (e.g., femur) and short bones (e.g., carpals).
• Bones are made up of compact bone (hard outer layer) and spongy bone (soft inner layer).
• The main function of the skeletal system is to support, protect, move, store minerals, produce blood cells, and allow muscle attachment.
• Bones are made up of living tissue that can repair themselves when broken or damaged.
• The skeletal system is made up of bones, cartilage, ligaments, tendons, joints, and muscles.
• The main function of the skeletal system is to support, protect, and allow movement.
• Bones have different shapes to perform specific functions such as support, movement, storage, and protection.
• Cartilage covers the ends of bones at joints to prevent friction during movement.
• The skeletal system is responsible for supporting the body, protecting organs, producing blood cells, storing minerals, and providing attachment points for muscles to move the body.
• The skeletal system is made up of the skull, rib cage, vertebral column, pelvis, and limbs.
• Muscle fibre


  Long, cylindrical, muscle cell

  
• Skeletal muscle


  Made up of bundles of muscle fibres held together
• Exercise


  1. Fibres contract & relax against each other

  2. Causes microscopic tears in the fibre

  3. Body heals, protein fills the gaps in tears

  4. Resulting in stronger muscles

  5. Increase in muscle size (depending on the type of exercise)

  
• Types of muscle fibres

  • Slow twitch (Type 1)
  • Fast twitch (Type 2)

  
• Slow twitch (Type 1) muscle fibres

  • Good oxygen supply
  • Cells get most of their energy from using oxygen
  • Use oxygen to produce a small amount of tension over a long period of time
  • Dark red
  • Greater amounts of myoglobin and mitochondria
  • Contractions are slow BUT can go on for long periods of time/repeated often
  • Resistant to fatigue
• Myoglobin


  Main responsibility is to carry O2 to muscles
• Mitochondria


  Organelle in cells where respiration and energy production occur
• Slow twitch fibres


  • Develop force slowly
  • Maintain/keep contractions longer
  • Higher aerobic capacity
  • Endurance athletes have a high percentage of slow twitch fibre muscles
• Aerobic capacity


  The maximal amount of oxygen your body can consume during maximal intensity exercise
• Fast twitch (Type 2) muscle fibres


  • Contract quickly (twice as fast as slow twitch)
  • Produce large amount of force in very short time
  • Tired/fatigue quickly
  • Release energy quickly
  • Designed for anaerobic capacity
• Anaerobic capacity


  Short, fast, high-intensity exercises that don't make your body use oxygen like it does for cardio (or aerobic) activities
• Subtypes of fast twitch fibres

  • Type 2a/11a (fast oxidative fiber)
  • Type 2b/11b (fast glycolytic fiber)

  
• Type 2a/11a muscle fibres


  • Have fast contractions and primarily use aerobic respiration
  • Red in colour
  • Large amounts of mitochondria
  • Produce fast, strong muscle contractions
  • Prone to fatigue more than type 1/medium fatigue

  
• Type 2b/11b muscle fibres


  • Use anaerobic metabolism to produce powerful, high-tension contractions but fatigue quickly
  • White in colour
  • Low myoglobin
  • Few mitochondria
  • Produce short, fast bursts of power
  • Fatigues quickly
• Aerobic metabolism is the most efficient mechanism used by the body to convert food energy into energy easily used by the body for fuel
• Anaerobic metabolism is the production of adenosine triphosphate (ATP) through energy pathways that do not require oxygen
• ATP


  Adenosine triphosphate, organic molecule that acts as main energy carrier in cells
• Soleus muscle vs Eye muscle

  • Soleus is an endurance muscle used for hours at a time, reaches peak tension in 20-80 /sec, contains mainly slow contracting muscle fibers
  • Eye muscle produces intermittent, rapid movements, reaches peak tension in 7-8m/sec, contains mostly fast contracting muscle fibers

  
• Most muscles perform a combination of functions (help maintain your body posture) & Rapid movements
• Muscles are made up of both types of fibers (Type 1 & 2), amounts will differ from muscle to muscle and from person to person

  
• Number of muscle fibers can't be altered by training, training can increase muscle mass by changing the size of muscle fibers rather than the type of muscle fibers

  
• Agonist muscles


  Muscles that provide the major force of a movement, also known as prime movers
• Antagonist muscles


  Muscles that oppose the agonist muscles, do not always relax and can help slow down or stop a movement
• Agonist-antagonist muscle pairs


  • Bicep-Triceps
  • Quadriceps-Hamstrings
  • Pectoralis Major-Trapezius
  • Hip adductor-Gluteus maximus
  • Deltoids-Latissimus Dorsi
  • Iliopsoas-Gluteus Maximus
  • Tibialis Anterior-Gastrocnemius
  • Rectus Abdominus-Erector Spinae
• Types of muscular contractions

  • Concentric
  • Eccentric
  • Isometric
• Concentric contraction


  Muscle shortens when tensing/experiencing a load
• Eccentric contraction


  Muscle lengthens under load
• Isometric contraction


  Muscles do not have to shorten or lengthen to create tension, results in very little or even no movement
• Myofibril


  Long, tubular structures running the length of the muscle fibre, embedded in the cell's sarcoplasm