Training Adaptations Flashcards
What are some neural adaptations which occur
Motor cortex activity increases when new movements are being learnt
Increased drive to agonist muscle which increases recruitment and firing rate
Reduces gto activity
What levels of improvements can be seen
Untrained 40% Moderately trained 20% Trained 16% Advanced 10% Elite 2%
What is the size principle
Low threshold units first with the largest motor unit
What is the purpose of PAP
To make it easier to recruit type 2 fibres
Why is the speed of contraction important
Lots of sports actions occur very fast resistance exercise can generate more force but slower over 300ms
How does increased motor neurone pool excitability increase performance
Recruitment of more motor units
Better unit synchronisation
Decrease in presynaptic inhibition
Greater central input to motor neurone
How does pap increase phosphorylation myosin light chain
Increase in calcium released from te sarcoplasmic reticulum activates MLC kinase which produces more atp available
Which fibres does pap effect
Type 2
What is the optimum timing
7-10 minutes pre
At least 3mins rest
If done over 10 minutes pre effect is reduced
What should be done for pap
Maximal efforts 90% 1rm
1-5 sets
Improvements of pap
1-10%
Effect of rt training on the neuromuscular junction
Increased area
Greater total length of nerve terminal branching
Increased end plate perimeter length and area
Greater dispersion of ACTH receptors in end plate region
What happens to the neuromuscular reflex potentiation
Enhanced the reflex response from muscle spindles by 20-50%
How much improvements in EMG activity can be seen from strength and power training
73%
Is neural activation higher
High intensity
Ballistic explosive faster velocities
Concentric when matched for intensity vs eccentric
When fatigue ensues
When is neural activation lower
Post work out
High volume training
During periods of detaining
What is cross education
By training one limb strength in the bilateral limb increases
What is bilateral deflect and how can it be reduced
Sum of strength of both limbs working alone is more than when working together
Bilateral training
Muscle mass factors
Genetics Pa Nutrition Endocrine Environmental Nervous system activation
How does skeletal muscle adapt to training
Increases size
Fibre type transitions
Enhances biochemical and ultra structural components
What two methods increases csa
Hypertrophy
Hyperplasia
What is hypertrophy
Increase in synthesis of contractile proteins
What is myogenisis
Satellite cells released from basal lamina Migrate to site of fibre damage Proliferate Differentiate into myoblasts Myoblasts fuse to form myotubules Mature to form new fibres
What is myogenisis up and down regulated by
Unregulated by :
MyoD
Myf5
Myogenin
Down regulated by:
Myostatin
What does exercise do to myogenin and myostatin
Increases myogenin
Decreases myostatin
What is released as soon as damage muscle occurs
Interleukins
Tumor necrosis factor
When are changes in muscle size detectable
3 weeks
Increased hypertrophy from what
Tension Blood flow occlusion Eccentric contractions Cell water content Cho protein content
How does hypertrophy occur from eccentric actions
Stretching muscle increases protein synthesis
How does hypertrophy occur from tension
Distrupts call membrane signalling an increases in growth factor release
How does hypertrophy occur from blood flow occlusion
Stopping fb increases bla production
How does hypertrophy occur from cell water content
Fully hydrated cells show increased protein synthesis
How does hypertrophy occur from cho and protein ingestion
Stimulates insulin release and provides aa
Name 3 growth factors and how they help hypertrophy
IGF AND fibroblast gf increase satellite cell division
Hepatocyte gf helps migration of satellite cells
What hormones promote hypertrophy
Gh
Testosterone
What Hormone inhibits hypertrophy and how
Cortisol and it blocks protein synthesis
Where does hyperplasia clearly occur
In animals
How much of CSa is due to hyperplasia
Less than 10%
What cells cause muscle cell remodelling
Dormant myogenic stem cells
Resistance training has what effect on intramuscular things
Increased myofibrilar volume Increased cytoplasmic density Increased sr and t tubule density Increased na/k pump activity Decreased mitochondrial density Decreased capillary density Increased buffering capacity
What types of stresses are there
Tension
Compression
Shear
What are tension stresses
Pulling forces
Stretching or elongation
Compression stresses
Push structure inwards
Compress length
Shear stresses
Skewing
Oblique forces
What is stress
Level of force encountered by a tissue
What is strain
Magnitude of deformation in proportional to stress applied
What is linear strain
Compressive/ tensile stresses that cause a change in length
Measured as % relative to resting length
What is shear strain
Bending of tissue or bone
Quantified by angle of deformation
What is poisons ratio
Longitudinal to lateral strain
What types of strain are there
Linear
Shear
What happens in bone remodelling
Bending forces
Migration of osteoblasts
Osteoblasts lay down collagen
New bone
What type of bone responds rapidly
Trabecular bone rather than cortical
How long until measurable changes in bone mass
6-8 months
What is MES
Minimal essential strain
Threshold stimulus that initiates new bone formation
How much is MES compared to the force required to fracture a bone
1/10 of the force
What factors effect bone remodelling
Weight baring Magnitude of load Rate of loading Direction of loading Volume of loading Pull of tendons on bone
Recommendations for bone strength and mass
Multi joint exercises Loading Fast velocities Rest moderate to long Variation in training stresses
What is collagen made of
Water 60-70% Fibroblasts Fibrocytes Elastin Collagen Ground substances
What are fibroblasts and cytes
Blasts are collagen producing cells
Cytes are mature cells
What is the primary stimulus for growth of connective tissue
Mechanical force
What is the relationship between adaptation and intensity in connective tissue
Higher the intensity the higher the adaptations
Changes which contribute to increase size and strength of connective tissue
Increased number and diameter of collagen fibres
Increase covalent cross links within hypertrophied fiber
Increased packing density of collagen fibrils
Purpose of cartilage
Provide smooth
Shock absorber
Aid attachment of connective tissue to bone
Does cartilage have is own blood supply
No
How does cartilage get O2 and nutrients
Diffusion from synovial fluids
Movement about a joint creates changes in pressure in te joint capsule that drives nutrients from synovial fluid towards cartilage
How to stimulate cartilage
Weight baring
Complete movements
Moderate aerobic training
Strenuous exercise doesn’t cause problems
