Chronic Musculoskeletal Adaptations to Exercise
This article or area is currently under construction and may only be partially complete. Please come back soon to see the finished work! (23/11/2022)
Original Editor - User Name
Top Contributors - Wanda van Niekerk and Jess Bell
Introduction[edit | edit source]
Effects of Deconditioning[edit | edit source]
Decrease in:
- Muscle mass (skeletal and cardiac)
- Muscle strength (skeletal and cardiac)
- Cardiovascular system function
- Total blood volume
- Plasma volume
- Heart volume
- Orthostatic tolerance
- Exercise tolerance
- Bone mineral density
Reversibility Principle[edit | edit source]
- Benefits of training are transient and reversible
- After 2 weeks of detraining
- Measurable reduction in work capacity
- After 2 weeks of detraining
Musculoskeletal Adaptations[edit | edit source]
Resistance Training[edit | edit source]
- Resistance training yields substantial strength gains via neuromuscular changes
- Important for overall fitness and health
- Critical for athletic training programmes
Gains in Muscular Fitness[edit | edit source]
- After 3 to 6 months of resistance training
- Learn to more effectively produce force
- Learn to produce true maximal movement
- Young men experience greatest absolute gains versus young women, older men, children
- Due to incredible muscle plasticity
- Strength gains result from
- ↑ muscle size
- Altered neural control
Neural Control[edit | edit source]
- Strength gain cannot occur without neural adaptations via plasticity
- Strength gain can occur without hypertrophy
- Property of motor system, not just muscle
- Motor unit recruitment, stimulation frequency, other neural factors essential
Strength training module - add info or image?
Mechanism of Muscle Strength Gain[edit | edit source]
Motor Unit Recruitment[edit | edit source]
- Normally motor units recruited asynchronously
- Synchronous recruitment leads to strength gains
- Facilitates contraction
- May produce more forceful contraction
- Improves rate of force development
- Increased capability to exert steady forces
- Resistance training leads to synchronous recruitment
- Strength gains may also result from greater motor unit recruitment
- Increased neural drive during maximal contraction
- Increased frequency of neural discharge (rate coding)
- Decreased inhibitory impulses
- Likely that some combination of improved motor unit synchronisation and motor unit recruitment results in strength gains
Autogenic Inhibition[edit | edit source]
- Normal intrinsic inhibitory mechanisms
- Golgi tendon organs
- Inhibit muscle contraction if tendon tension too high
- Prevent damage to bones and tendons
- Training can decrease inhibitory impulses
- Muscle can generate more force
- May also explain superhuman feats of strength
Muscle Hypertrophy[edit | edit source]
- Hypertrophy = increase in muscle size
- Transient hypertrophy (after exercise bout)
- Due to oedema formation from plasma fluid
- Disappears within hours
- Chronic hypertrophy (long term)
- Reflects actual structural change in muscle
- Fibre hypertrophy, fibre hyperplasia, or both
Fibre Hypertrophy[edit | edit source]
- More myofibrils
- More actin, myosin filaments
- More sarcoplasma
- More connective tissue
- Resistance training → ↑ protein synthesis
Resources[edit | edit source]
- bulleted list
- x
or
- numbered list
- x