Lecture 14 - Chronic Adaptations to Strength Training Flashcards
What factors effect adaptation?
- Training program design
- Concurrent activities (activities that negatively effect adaptation)
- Genotype (Your capacity for adaptation)
- Gender
- Training history
- Age
- Nutrition status
What factors does power vs strength training improve?
- Power training: Increased neural
drive, increased force and RFD - Strength training: increased neural drive and muscle thickness, increased force and RFD.
What is best for improving vertical jump height? improved strength or coordination ?
- Neither are better but a combination of the two resulted in better jump height.
Strength improvements in the absence of increases in muscle size may result from what ?
- Neural adaptations
How do strength and hypertrophy training in the mechanisms they fatigue and their long term adaptations.
- Strength training is done at high weight for low reps. It fatigues the CNS and results in adaptation of the neural system.
- Hypertrophy training is done at moderate weight. it fatigues the muscle ( glycogen depletion etc.) and results in adaptation of the muscles themselves.
Why does CSA only account for 50% of force differences between individuals
- Differences in specific tension
Between the quads and hamstrings which has the:
- Greatest CSA
- Largest pennation angle
- Most sarcomeres in series
- Longest fibre length.
- Larges force producing capabilities
- Fastest velocity capabilities.
- Greatest CSA = Quads
- Largest pennation angle = quads
- Most sarcomeres in series - hamstrings
- Longest fibre length - hamstrings
- Greatest force capacities - quads
- Fastest velocity capability - hamstrings.
Which is capable of greater force production, pennate or non pennate muscles and why?
- Pennate muscle because more fibres are packed into set muscles.
What is the role of muscle co-contractions and how can this change through training?
- A protective effect to stabilise a joint to compensate for passive structures.
- Can be reduced through training allowing a greater contraction of against muscle, resulting in more force being produces.
A neural adaption of training is increased neural drive. What is this and what can cause it?
- Neural drive is a better activation of the muscle, resulting in bigger improvements in strength irrespective of muscle growth. - Can be caused by : - Increased MU recruitment - Increased firing frequency - Enhanced MU synchronisation
What factors explain the high rates of
hamstring injury recurrence?
- The persistence of risk factors – modifiable and non-modifiable
- Reduced flexibility – link between hamstring injuries and flexibility is questionable
- Muscle weakness
- Selective hamstring atrophy
- Shifts in the torque-angle relationship
- Neuromuscular inhibition
- Avoidance of excessive stretch.
How does firing frequence of MU’s change with training?
- Rapid contractions (untrained) = 60-120 Hz
- Rapid contractions (trained) = >200 Hz
- High force contractions = 30-60 Hz
During what stages of a training program lasting 12 weeks do the neural and muscular adaptations occur in the traditional time course model?
- Neural adaptations during initial stages (<6-8 weeks)
- Muscular adaptations during later stages (8-12 weeks)
What is enhanced MU synchronisation ?
- Improvement in timing of the action potentials discharged by the concurrently active MU’s.
What is sarcopenia and what is it caused by ?
- The loss of muscle mass with aging
- Caused by MU restructuring, Protein deficiency and changes in hormone concentrations
What are the potential types of neural adaptations?
- Enhanced output from supraspinal centres
- Reduced co-activation of antagonist muscles
- Greater activation of agonist and synergist muscles
- Enhanced coupling among spinal interneurons = cross education
- Changes in descending drive
- Shared input to motor neurons that increases MU
synchronisation - Greater muscle activation
- Heightened excitability and altered connections onto motor neurons.
What are the stimuli for muscle hypertrophy to occur?
- Muscle tension
- Muscle damage
- Metabolic stress
What is the main causes for increases in muscle size?
- Hypertrophy of muscle fibres, preferable type 2.
What is the difference between ACSA and PCSA?
- ACSA - measurement perpendicular to long axis
- PCSA - measurement perpendicular to fibres
Why is there a greater level of co-contraction in females?
- Greater joint laxity
- Smaller agonist musculature
- Lower quality muscle mass
What is blood flow restriction training and how does it work, plus mechanism of this?
- It is the placement of a cuff at proximal part of arm/leg.
- Works by increasing MU recruitment resting in increases in size and strength why paired with low load resistance.
