Ex Phys CH14

concentric action

occurs in dynamic activities where muscles shorten and produce tension through the range of motion

eccentric action

occurs when external resistance exceeds muscle force, and muscle lengthens as tension develops

isometric action

occurs when a muscle generates force and attempts to shorten but cannot overcome the external resistance, increases muscular strength, produces tension with no change in length of muscle and no movement at joint

Dynamic Constant External Resistance (DCER)

Implies that the external weight or resistance remains constant throughout the movement

isokinetic

has a constant velocity of movement

muscular strength

the maximum force, tension, or torque generated by a muscle or muscle groups

it refers to the fact that the total work accomplished by muscle action depends on the load placed on the muscle. the area from 60% to 100% 1RM represents the strength training zone (the training stimulus that optimizes strength improvement

explain the load-repetition relationship

it refers to the fact that the absolute or peak force generated in a movement depends on the speed of muscle lengthening and shortening. muscle shorten and lengthen at different maximum velocities depending on the load placed on them. as the load increase, maximum shortening velocity decreases. a muscle's force-generating capacity rapidly declines with increased shortening velocity

explain the force-velocity relationship

genetics, nervous system activation, environmental factors, endocrine influences, nutritional status, physical activity

what are the 6 factors that impact muscle mass development and maintenance

genetics

what is the main factor that impacts the development and maintenance of muscle mass

hypertrophy

an increase in muscle size that is the result of a fundamental biological adaptation

1. hypertrophy 2. hyperplasia

what are the 2 ways that there can be an increase in muscle size

hyperplasia

an increase in the number of cells, not the size

hypertrophy and neural adaptations

what are 2 reasons for an increase in muscle strengths

for the first 3 weeks strength gains are the result of neural adaptations and week 3-6 is when hypertrophy will occur and then there is usually a ceiling of strength gains

describe how the timeline of events for increase in strength for a sedentary person

FT fibers

do FT or ST fibers increase in size to a greater degree

1. increased CNS activation 2. improved motor unit synchronization 3. lowered neural inhibitory reflexes

what are the 3 types of neural adaptations

spinal (simple) reflex

type of reflex that involves a sensory and motor neuron. it is the most simplistic type of reflex. happens before the stimulus can reach the brain. there is a stretch and tells muscle to contract

patellar tendon tap reflex and myotonic (stretch) reflex

what are 2 examples of spinal reflexes

flexion reflex

type of reflex that involves an interneuron

touching a hot stove and immediately pulling your hand back

give an example of a flexion reflex

reciprocal inhibition

type of reflex where opposite neuron has to tell muscle to relax

crossed extensor reflex

a more complex type of reflex where it crosses to other side and that limb extends. the other side pushes to get away

IPSP, not blinking while putting in a contact

conditioned (learned) reflexes

proprioceptors

tells us where our body is in space

vestibular and kinesthesis

what are the two main types of proprioceptors

muscle spindles and Golgi tendon organs

what are the 2 types of kinesthesis proprioceptors

intramural muscle fiber

location of muscle spindles

stretch and lengthening

stimulus for muscle spindle activation

concentric contraction

response of muscle spindles

patellar tendon tap

example of muscle spindles

where the muscle and tendon come together

location of Golgi tendon organ

tension, force production, lengthening

stimulus for the activation of Golgi tendon organ

inhibitory and relaxation

response of the Golgi tendon organ

bilateral deficit

single limbs can produce more force on their own than when activated together

the opposite side gets told to inhibit

why does a bilateral deficit occur

through conditioned reflexes

how can a bilateral deficit be improved

cross education

refers to if one side is trained, the opposite side will also see neural adaptations, increase in strength to about 60% of the trained limb

atrophy

shrinking muscle, immobilization of a limb results in decreased muscle fiber size

be able to explain some health benefits to resistance training.

- increased bone density

- better body composition

- functional ADL strength

- increased insulin sensitivity

- increased BMR

- low diastolic BP

- reduced lower back pain

absolute muscle strength and relative muscle strength

what are 2 ways to determine whether true differences between genders really exist

50%

how much less absolute upper body strength does women have than men

30%

how much less absolute lower body strength does women have than men

the amount of muscle mass that one has

what is the biggest connection between strength differences and gender

- 2-4 sets of 8 to 10 exercises,

- one exercise for each major muscle group,

- 8 to 15 reps (more for older/cardiac patients then decrease load),

- 2 to 3 days per week

what are the parameters for a resistance training program for adults

decrease the weight to 10-15 RM load

how should a resistance training program be modified for an older/cardiac patient

concentric-only muscle actions with high reps and low resistance

what are the parameters for resistance training for children

incomplete skeletal development which could lead to potential bone and joint injury

what is the main thing that raises concern about resistance training for children

specificity

adaptations to a resistance training program will be specific to the characteristics of the program this ensures that adaptations transfer to sport

specificity, overload, progression and periodization

what are the 4 principles of resistance training for athletes

increased load/resistance, increased reps, and increased speed of action

what are the 3 ways that overload can be achieved

progression

refers to the volume of training must be increased periodically to maintain an overload and continue to see adapatations

periodization

refers to variation in training and volume and intensity over a specific time period, goal to prevent staleness while peaking physiologically for competition

preparation phase

phase of periodization that emphasizes modest strength development with high volume, low intensity workouts

first transition phase

phase of periodization that emphasizes strength development with workouts of moderate volume and moderate intensity

competition phase

phase of periodization where selective strength development is emphasized with low-volume high-intensity workouts plus short period of interval training that emphasizes sport-specific exercises

second transition phase (active recovery)

phase of periodization that emphasizes recreational activities and low-intensity workouts that incorporate different exercise modes

Delayed Onset Muscle Soreness (DOMS)

occurs 24-48 hours post-workout, eccentric movements contribute the most, results from inflammation, tenderness, and pain

types of muscular strength training systems.

- DCER

- Isometric

- variable resistance training

- isokinetic training

- plyometric training

Reflexes from simple to complex

- Spinal (simple)/ myotonic ex) patellar

- flexion (3 neurons, interneuron) ex) hand on hot stove and biceps activate to lift hand

- reciprocal inhibition: ex) hand on stove; triceps relax to allow concentric contraction of the biceps

- crossed extensor reflex: ex) stepping on a lego other leg activates to get pressure off the lego

- conditioned reflex: IPSP, ex) not blinking when putting in a contact lens

muscle spindle reflex

location: in between muscle fibers (inter capsule)

example: patellar tendon reflex

stimulus: stretching of the muscle

response: causes same muscle to contract

Golgi tendon organ

location: Golgi tendon

stimulus: tension with contraction

response: relaxation of the same muscle

example: PNF