Training and conditioning exam 2

muscular strength

what we normally test, when velocity is 0

the maximum contractile force against a resistance in a single contraction

muscular endurance

submaximum contractile force for an extended period

isometric

contration: static, no visible movement

isotonic

contraction: resistance is the same, velocity can change with concentric or eccentric, where the tension changes as a function of the strength curve.

isokinetic

contraction: Velocity is constant, resistance changes

Specialized, changes time under pressure

not normally tested

what does it mean to fail

max strength when velocity is 0

neural adaptions significance

#1 adaption for untrained individuals

neural adaptions mechanically

Central adaptations: motor cortex activity increases

Spinal tuning via descending corticospinal tracks

More motor units are recruited, rate of firing /\, and the firing is more sycnronized.

size principle for neurons

Selective motor unit recruitment

Continuum of recruiting low type 1 -> high type 2

muscle fiber dextarity

a muscle fiber can only be innervated by 1 neuron, but a neuron can innervate many fibers.

The less fibers a neuron innervates, the stronger the stimulus is on the fiber.

changes to neuromuscular junction

1)Increases total area of the neuromuscular junction

2)More dispersed, irregular shped synapses and a greater total length of nerve terminal branching

3)Increased end-plate perimeter lengthand area + greater dispersion on acetylcholine receptors with the end-plate region.(more rapid)

Muscle spindles/stretch reflex

1)Theres a myotatic reflex

2)Anaerobic training may enhance the reflex response, which enhances the magnitude and rate of force development

3)The amount of innervation is altered.

cross education

exercising muscles undergoing unilateral resistance training produces an increase in strength and neural activity in the contralateral limb (22%)

bilateral deficit

untrained individuals- force reduction in untrained individuals in lower when both limbs contract together and increased when contracted separately.

Muscular adaptations

Increasing size

enhancing biochemical pathways

increases myofibular volume

sarcoplasmic reticulum and t-tubual density

sodium-potasium atpase activity

Reduced mitochondrial density and capillary density (specificity!)

Increase buffering capacity (acid-base balance bc of lactate + H+!)

Changes in substrate and enzyme content/activity

hypertrophy

Muscular enlargement from an increase in the cross-sectional area of the existing fibers

This increases the synthesis of contractile protein’s actin, myosin in the myofibril

Increase in the number of myofibrils within a muscle fiber

cross sectional area increases, which causes:

hypertrophy

increase in synth and decreases in degradation of proteins

fiber changes

resistance bc there are more type I and II fibers

which fiber increases the greatest during muscular adaption

Type II

what happens to fiber types in the body with muscular resistance training

fibers transition from type I-II

but only 10-15% bc a lot of this is genetic

Modeling (bones)

Causes the bone to bend, creating a stimulus for new bone formation to regions experiencing the greatest deformation!

(osteogenic stimuli!)

Osteoblasts lay down additional collagen fibers

Dormant osteoblasts migrate to these areas

Collagen fibers become mineralized

physiology to bones key notes

Trabecular bone (sponge) responds more rapidly than cortical (compact)

MES and what it does

MES is 1/10 of the amount of force to fracture the bone

we need to hit this to see any bone adaption

muscle strength and hypertrophy effects bone mineral density by..

increase the force exerted on the bones, which corresponds to an increase in bone mineral density

factors to bone density

age, sex, experience/ specificity (fighting sports have more dense bones bc of impact)

relative energy disorder and menopausal bone loss effects

increases risk of osteoporosis

specificity and bone density

focuses the stimulation of bone formation on certain parts

ex: Using structural exercises through hip/ spine allows for greater absolute loads of training (osteogenic stimuli)

connective tissue adaption

increased load baring capacity, stimulates growth/change proportional to intensity

tendon, ligaments, facia adaptions

An increase in collagen fibril diameter

• A greater number of covalent cross-links within the hypertrophied

fiber

• An increase in the number of collagen fibrils

• An increase in the packing density of collagen fibrils

how to stimulate connective tissue adaption

high- intensity loading and forces through full ROM

functions of cartilage

Provide a smooth joint articulating surface

Act as a shock absorber for forces directed through the joint

Aid in the attachment of connective tissue to the skeleton

joint mobility relating to joint health

1)Cartilage lacks its own blood supply and must depend on

diffusion of oxygen and nutrients from synovial fluid.

2)Movement about a joint creates changes in pressure in the joint

capsule that drive nutrients from the synovial fluid toward the

articular cartilage of the joint.

endocrine adaptions (acute)

Does NOT change resting hormonal content

Our anabolic response to the same workout is increased in a trained individual

why is receptor content change important for exercise

We upregulate androgen receptor content for about 48 - 72 hours

Application: we want to plan resistance training to get within the 48-72 hr window to take advantage of the upped androgen receptor content

We get the most out of it

cardiovasular response and BP (acute)

CO, SV, HR, Oxygen uptake, systolic AND diastolic

Systolic increases non linearly

Big peaks and valleys in MAP, and increases as we get close to failure

Why we pass out during deadlifts

Someone who has cardiovascular disease needs to be careful

cardiovascular- chronic at rest

Anaerobic training leads to a decrease or no change in resting HR and BP

Resistance training alters cardiac dimensions

Increase left ventricular wall thickness

*different than aerobic training bc they arent training the same way

cardiovascular- chronic at not rest

Reduces cardiovascular response reduces to an absolute intenisty/workload

If we squat the same weight for 8 weeks, itll get easier and require less effort

(relative= squating the same RM %, not the same weight)

Ventilation is NOT effected really

power training

Increases force at high velocities/rate of force development

Peak power is around 30-60% of 1RM (squat)

46-62% (ballistic bench press)