CH 12: Muscular Strength and Endurance

  1. Muscular Strength
    • ability of a muscle to generate maximal force
    • Weight an individual can life during one maximal effort
  2. Muscular Endurance
    Ability to generate force over and over
  3. Muscle Structre
    • Skeletal muscles
    • Collection of thin long cells - fibers
    • Surrounded y fascica
    • Muscle attached to bone y connective tissue-tendons
    • Muscles can only pull the bone
  4. Muscle Function
    • Actions are regulated by electrical signals from motor nerves
    • Originates in the spinal cord - sends messages to individual muscles throughout the body
    • Motor nerve and muscle fiber make contact at a neurotransmitter junction
  5. Skeletal muscle exercise
    • Isotonic - movement of a body part at  a joint
    • Isometric - Developmental muscular tension - no movement
    • Isokinetic - performed at constant velocity
    • speed of muscle shortening and lengthening is regulated at a fixed rate
  6. Muscle Action
    • Isometric - do no involve joint movement
    • Concentric - causes movement against resistance or gravity - isotonic or isokinetic exercise
    • Eccentric - control movement with resistance or gravity - muscle lengthens
  7. Muscle Fibers
    • Slow-twitch: contract slowly and produce small amounts of force - highly resistance to fatigue - walking or jogging
    • Intermediate: combo of characteristics of slow and fast-twitch - contract rapidly - produce great force - resist fatigue - well developed aerobic capacity
    • Fast-twitch: contract rapidly and produce great amount of force - fatigue quickly - jumping, sprinting, weight lifting - easily damaged with strenuous exercise - soreness - individuals with a predominance of fast-twitch  muscle fibers may be more susceptible to obesity and diabetes
  8. Most exercises use a small amount of fibers available in a muscle group
    • Walking 30% in the lengs
    • Intense exercise uses more, more force
    • Fiber recruitment - involving more muscle fibers to produce increased muscular force
  9. Muscle Strength
    • Amount of force a muscle can generate
    • Number of fibers recruited during contraction - larger muscle=more force
  10. Evaluation of muscular Strength and Endurance
    • One-rep max
    • Push-up test
    • Sit-up test
    • Curl-up test
  11. 2 Training Principle
    • Overload
    • Specificity
  12. Progressive resistance
    Application of overload - progressively increase resistance
  13. Specificity
    specific muscle group and training intensity
  14. Intensity
    • high weight - strength
    • high reps - endurance
  15. Physiological changes
    • Hypertrophy - depends on diet - testosterone - training
    • Body composition
    • Flexibility
    • NOT hyperplasia - new muscle fibers
  16. Flexibility
    • Range of motion of a joint
    • Allows us to bend, twist, and reach without experiencing pain or stiffness
    • Stretching can alleviate tightness at a joint
  17. Structural limitations to flexibility or movement
    • Shape of the bones - ball and socket vs hinge
    • Stiff muscle - warm up
    • Connective tissue - ligaments and cartilage
    • Tendons - muscle tight = tight tendon
    • Tight skin
  18. Ligaments
    hold bones together
  19. Cartilage
    • Forms pad on end of bones
    • Shock absorber
  20. Stretch reflex
    Involuntary contraction due to muscle stretching rapidly
  21. Proprioceptor
    Receptor in muscle or tendon that provides feedback to the brain about position of body part
  22. Golgi tendon organ - proprioceptor in tendons
  23. Benefits of Flexibility
    • Joint mobility
    • Efficient body
    • Good posture
  24. Healthy Joints
    • Limited range of motion = scar tissue - range of motion can keep joint from becoming immobile
    • Joint mobility = joint lubrication - synovial fluid
    • Reduces tension within the fibers of the muscle
  25. Lower back pain? (flexibility)
    • Weak abdominal muscles
    • Hamstrings
    • Hip flexors
    • Psychological
    • Social
    • Physical
  26. Stand up STRAIGHT
    Bad posture occurs when you hold positions that stretch muscles on one side of a joint, while shortening the on the other side
  27. Dynamic Stretching
    Involves moving the joints through the full range of motion
  28. Static Stretching
    Slowly lengthens a muscle to a point where further movement is limited
  29. Ballistic Stretching
    Sudden and forceful bouncing to stretch muscles
Card Set
CH 12: Muscular Strength and Endurance
muscular strength and endurance