resistance exercise principles - pt 1

what are neurologic changes

improved motor unit recruitment and temporal summation (increase motor unit firing rate)

-these changes occur fairly quickly (responsible for majority of strength gains up to 4-6 weeks)

what is muscle hypertrophy

an actual increase in a muscle’s cross-sectional area

when does muscle hypertrophy occur

after 4-6 weeks, closer to 8

what is 1st to gain and 1st to lose during strength

neurologic adaptations

what is muscle strength

exercise that will increase the tension/force that the contracting muscle can create (usually related to cross-sectional area)

strength increased tension can be due to

-neuro adaptations

-hypertrophy

will all resistance exercises lead to an improvement in muscle tension

no

to improve muscle strengty, you must apply ___

overlaod principle

what is overload principle

increased training volume (load, weight, reps and sets

what is the guiding principle for muscle strength

typical strength programs utilize 2-3 sets of 8-15 reps/set (ex: 3 sets of 10)

-training program done at 70-80% or 1RM or at 100% 10RM

what is muscle endurance

ability to perform low load-high rep resistance exercise

proximal stability for distal mobility…

more proximal muscles are type 1 or endurance muscles

in acute/subacute stage of pathology, why would low load-high reps be beneficial

1- more comfortable

2- decreased joint irritation

what is the general rule for PT with resistance exerecise

endurance 1st → strength

what is the guiding principle for muscle endurance

endurance programs between 3-6 sets of 20+ reps/set

endurance resistance training typically does/does not result in increase muscle hypertrophy

does not!

thus no increase in tension produced in a one time effort

what is muscle power

force x distance / time

what is the guiding principle for muscle power

1 set of 6-8 reps at very high load

-power programs are usually high load-low reps

what are the 3 disadvantages to muscle power programs

1- high joint forces → joint irritation

2- heavy eccentric work → leads to microtrauma to muscle fibers

3- safety concerns

what is the SAID principle

specific adaptation to imposed demands

whatever system trying to improve need to train

-SAID principle

-Specificity of training

what concepts of muscle endurance programs and developing a motor pattern are similar?

need repetitions and low load

progress as tolerated

what is isotonic exercise

combo of concentric and eccentric muscle contractions carried out dynamically against a constant or variable load

force production in muscle contractions in order from lowest to highest

isometric→concentric→eccentric

how is constant load defined

when resistance stays constant throughout the ROM it is lifted

-effected torque provided by the “constant load” will change at all points in the ROM

what is the advantage of constant load

easy to quantify progress

what is the disadvantage to constant load

only maximally stress the muscle at one point (which is the weakest point)

do not maximally stress muscle at all other points in ROM

variables in resistance exercise programs

1-load

2-sets

3-reps

4-speed

5-frequency

6-type of muscle contraction

7-open vs closed chain

what must be used in order to increase muscle performance

progressively overloaded (overload principle)

-increasing the load or resistance

-can be difficult to determine initial resistancew

what is DeLorme’s Repetition Maximum (RM)

technique provides a way to eliminate the guesswork of initial resistance

what is an RM

the greatest amount of load that can be moved through the full ROM a specific number of times

what are common RM’s

1RM, 10RM, 20RM

what does the ACSM recommend for trials to establish an RM

no greater than 5 trials

what is the equation for 1RM

(Wx36) / (37-R)

typical strength programs utilize 2-3 sets of 8-15 reps/set

training program done at 70-80% of 1 Rm load or at 100% of 10 RM load

all resistance exercises (isometric, isotonic, or isokinetic) may be done

submaximally or maximally

repetitions in relation to overload principle

can achieve overlaod principle by increased number of reps

sets in relation to overload

keep in mind the minimum rest time needed between sets

-number of sets will vary depending on the goals of rehab

volume is comprised of combination of _____, reps, and _____

sets

load

you can manipulate volume to lead to

development of a specific goal related to resistance exercise

what is periodization

type of resistance training where subject varies the number or reps and sets, as well as amount of resistance (load)

what does periodization lead to

peaking for a competition, event, or athletic seasion

when is periodization utilized

high power-type events

what is frequency

number of times/day or times/week

what is the general rule for frequency

endurance→ daily or multiple times per day

strength→ rest day in between (2-3x/week)

power→ oncer or at max twice/week for given muscle group

what to keep in minde with speed of exercise

relationship between speed of contraction and force production for both concentric and eccentric contractions

-isokinetic can be 0-500 degreesu

uses for isometrics

typically used in early sub-acute stage, after immobilization or when resistance throughout the range is not tolerated

why would you use partial ROM

typically secondary to injury restrictions

-goal is to progress to full ROM exercise

which is more functional exercise open or closed chain

closed chain

advantages of closed chain

-co contraction of muscles around joint lead to decreased shear forces

-improved joint proprioception due to weight-bearing nature

-more functional, especially LE

disadvantage to close chain

-due to co-contraction around the joint, you have decreased the ability to isolate muscle (not optimal recruitment of muscle)

advantage for open chain

greater ability to isolate muscle activity

disadvantage for open chain

greater shear forces during exercise