W11 - Principles of Resistance Training + Ch.6

How does speed of muscle contraction (force-velocity relationship) affect tension generation of skeletal muscle?

Concentric contraction: Increased speed and decreased tension. Eccentric contraction: Increased speed and increased tension.

How does length-tension relationship of muscle at time of contraction affect tension generation of skeletal muscle?

Muscle produces greatest tension when it is near or at the physiological resting length at the time of contraction.

How does muscle power(power training) differentiate from plyo or stretch-shortening drills?

Time of the movement for plyo and stretch-shortening drills is the variable most manipulated.

what is strength training?

Practice of using muscle force to raise, lower, or control heavy external loads for relatively low number of reps or over a short period of time.

Progression for neuromuscular control

Proximal to distal control

What are key factors that affect muscle power?

Relationship between force and velocity

How does muscle architecture-fiber arrangement and fiber length affect tension generation of skeletal muscle?

Short fibers with pennate and multipennate design are typical in high force-producing muscles. Long fibers with parallel design are typically in muscle w/ fast shortening rates but lower force production.

In late adulthood, what is significant about the 8th decade?

Skeletal muscle mass will have decreased by 50% compared to peak muscle mass

Why do we start with muscular endurance training?

Slow-twitch muscle fibers are the first to atrophy when there is joint swelling, trauma, or immobilization.

What does SAID stand for?

Specific Adaptations to Imposed Demands Principle

Why is stabilization important and what are the types?

Stabilization ensures correct muscle action and movement. External stabilization: applied manually by a therapist or patient with equipment such as belts Internal stabilization: iso contraction of an adjacent muscle group that does not impact the desired movement pattern but holds the proximal segment of the muscle being strengthened firmly in place.

How do you progress types of muscle contractions?

Static to dynamic. Concentric and eccentric: variable progression

Strength and Endurance training adaption for metabolic system and enzymatic activity

Strength: - Increase ATP and PC storage - increase myoglobin storage - increase creatine phosphate - increase myokinase Endurance: - Increase ATP and PC storage - increase myoglobin storage - increase creatine phosphate - increase myokinase - increase of stored tryglycerides

Strength and Endurance training adaption for body composition

Strength: - increase lean body mass, decrease % body fat Endurance: - no change in lean body mass, decrease % body fat

Strength and Endurance training adaption for connective tissue

Strength: - increased tensile strength of tendons, ligaments and connective tissue in muscle - increased bone mineral density - no change or possible increase in bone mass Endurance: - increased tensile strength of tendons, ligaments and connective tissue in muscle - increased bone mineralization with land-based, weight-bearing activities

Strength and Endurance training adaption for neural system

Strength: - motor unit recruitment - increase rate of firing (decrease twitch contraction time) - increase synchronized of firing Endurance: - no changes

Strength and Endurance training adaption for skeletal muscle structure

Strength: - Muscle fibers hypertrophy(greatest in trype IIB) - Remodeling of Type IIA&B - decrease or no change in capillary bed density - decrease mitochondrial density and volume Endurance: - minimal or no muscle hypertrophy - increase in capillary bed density - increase in mitochondrial density and volume (increase in number and size)

How can recovery from exercise occur more rapidly?

Studies show that light exercise performed during recovery period (active recovery) occur more rapidly than recovery from exercise with total rest (passive recovery).

How do you progress intensity (exercise load)?

Submaximal to maximal (or near max). Go from low load to high load

What is exercise volume?

Summation of the total number of repetitions and sets of a particular exercise during a single exercise session.

Describe cardiopulmonary (general) fatigue.

Systemic fatigue as a result of prolonged PA. (walking, jogging, cycling, or repetitive work). Related to the body using O2 efficiently.

What is functional strength?

The ability of neuromuscular system to produce appropriate amount of force during functional activities in a smooth and coordinated manner

When is muscle power greatest?

The greater the intensity of the exercise and the shorter the time period taken to generate force.

How does recruitment of motor units affect tension generation of skeletal muscle?

The greater the number and synchronization of motor units firing, the greater the force production.

How does the rate of motor unit firing affect tension generation of skeletal muscle?

The higher the firing frequency, the greater the tension

How are intensity, external resistance related to reps?

The higher the intensity or external force the lower the number of repetitions and sets. The lower the external resistance the greater the number of repetitions and sets.

How do muscles adapt to endurance?

They increase their oxidative and metabolic capacities. Allows for better delivery and use of O2.

What is the SAID principle?

To improve muscle performance, the resistance program should be matched to that elements constructs. Exercises in a program should mimic the anticipated function.

Describe type I fibers

Tonic and slow-twitch. Low muscle tension, sustains muscle contractions for long periods. Geared toward aerobic metabolism, more resistant to fatigue, found in postural muscles.

Energy system characteristics for fiber types.

Type 1: aerobic IIA: aerobic IIB: anaerobic

Resistance to fatigue characteristics for fiber types.

Type I: High Type IIA: Intermediate Type IIB: low

Max muscle shortening velocity characteristics for fiber types.

Type I: slow IIA: fast IIB: fast

twitch rate characteristics for fiber types.

Type I: slow IIA: fast IIB: fast

Diameter characteristics for fiber types.

Type I: small IIA: intermediate IIB: large

How to you progress body position (nonweight bearing to weight bearing)

Variable: depending on the pathology and impairments, weight-bearing restrictions (pain, swelling, instability) and goals of the rehab program.

How do you progress frequency?

Variable: depends on the intensity and volume of exercise

What are the implementations of resistance training?

W/u: using light, repetitive, dynamic, site-specific movements w/o applying resistance Placement of resistance: mostly to the distal end of the segment, resistance can be applied to joint if stable and pain-free Direction of resistance: applied in the opposite direction to the desired motion

When are training-induced gains in muscle strength and mass greater?

With max. effort eccentric training

When does muscle mass peak for men and women?

Women: 16-20 yrs Men: 18-25yrs

When does strength begin to decline? With which population?

Young and middle adulthood. Starts the third decade, strength declines between 8-10% per decade through the 5th or 6th decade.

What is resistance exercise?

activity which dynamic or static muscle contraction is resisted by an outside force applied manually or mechanically

What is acute exercise recovery?

average of 3-4 minutes to reach 90-95% of pre-exercise capacity.

Define overtraining

decline in physical performance in healthy individual participating in high-intensity, high volume strength and endurance training

What is muscle fatigue?

diminished response of muscle to a repeated stimulus. Muscle repeatedly contracts statically or dynamically against a load.

For which populations should heavy resistance training be avoided?

for children, older adults and pt's with osteoporosis

What are the types of Isometric exercises?

muscle-setting (low intensity iso contraction), stabilization (submax but sustained level of co-contraction to improve stability), and multi-angle iso's (resistance applied at multiple joint positions within the available ROM)

Define overwork

progressive deterioration of strength in muscles already weakened

How do you progress ROM?

short arc to full arc. Stable portion of range to unstable portion of range

Progression for velocity of movement

slow to fast velocities

What is exercise intensity?

the amount of external resistance imposed on the contracting muscle during each repetition.

How does cross-section and size of the muscle affect tension generation of skeletal muscle?

the larger the diameter, the greater its tension-producing capacity

Capillary density characteristics for fiber types.

type I: high type IIA: high type IIB: low

Progression for plane of movement

uniplanar to multiplanar

How are velocity and force related during a max effort eccentric contraction?

velocity of active muscle length increases, force production in a muscle initially increases.

When are manual resistance exercises useful?

- During early stages of a program when muscles are weak - when range of joint movements need to be carefully controlled

What are the age-related changes in muscle and muscle performance during infancy, early childhood, and preadolescence?

- at birth, muscle accounts for about 25% of body weight - total # of muscle fibers is established prior to birth or early infancy - postnatal changes in distribution of type 1 and 2 fibers in muscles are relatively complete by the end of the 1st year - muscle mass and muscle strength is approx. 10% greater in boys than girls

What are the benefits of resistance training?

- enhanced muscle performance through restoration, improvement or maintenance - Increased connective tissue strength - increased bone density - decreased joint stress during PA - Reduced soft tissue injury during PA - improved capacity for repair and healing of damaged tissues - improved balance - + body changes in composition - + perception of disability

How much muscle mass accounts for total body weight in early adulthood?

40%, men having more muscle mass than women.

What are the determinants of a resistance exercise program?

Alignment, stabilization, intensity, volume, exercise order, frequency, rest interval, duration, mode, velocity, periodization, integration.

When does decrease in muscle mass begin to occur?

As early as 25 yrs

Who has a more rapid acceleration in muscle fiber size and muscle mass during puberty?

Boys, muscle mass increases more than 30% per year.

Does muscle mass or strength develop first in girls and boys?

Boys: muscle mass peaks before muscle strength Girls: strength develops before peak mass

What is cardiopulm fatigue and endurance associated with?

Decreased blood sugar levels, decreased glycogen stores in muscle and liver, and depletion of potassium (especially in elderly patients).

What are some neuromuscular factors for decreased muscle strength?

Decreased muscle mass, decreased muscle fibers (type 1&2), decreased cross sectional size of muscle, selective atrophy of type 2 fibers, change in length tension relationships.

Why does PA help someone with OA?

During muscular contraction, resistance to bony attachment increases bone density by calcifying

When does the performance of functional skills begin to decline?

During the 6th decade

Is resistance training contraindicated when there is inflammation?

Dynamic and static resistance training is contraindicated. (ex. pt's with guillan-barre or inflammatory muscle disease)

Which type of contraction is more efficient metabolically and generates less fatigue?

Eccentric muscle contraction

What type of training would be beneficial for patients with impaired muscle performance?

Endurance training has a more + impact on improving a function than strength training.

How is alignment important for resistance exercise program?

Essential to have proper alignment of a limb or body segments. Fiber orientation needs to be considered.

What is strength?

Extent that the contractile elements of muscle produce force. The contractile tissue generate enough force to meet physical and functional demands. This is the greatest measurable force to overcome resistance.

What is the equation for power and what is it?

F x D/time. Related to the strength and speed of movement.

Describe type II fibers.

Fast twitch General fibers: create great amount of tension within a short period of time. Type IIA: geared toward aerobic metabolism Type IIB: anaerobic metabolic activity and fatigue quicker than type IIA.

How does the type of muscle contraction affect tension generation of skeletal muscle?

Force output from greatest to least - eccentric, isometric, concentric muscle contraction

What are the characteristics of muscle fatigue?

Gradual decline in the force producing capacity of the neuromuscular system. Decrease in energy, O2, and reduced sensitivity and availability of intracellular calcium

In late adulthood, what comes with a loss of strength?

Gradual deterioration of functional abilities and an increase in the frequency of falling.

How does moment arm between muscle force vector and axis of joint rotation affect tension generation of skeletal muscle?

Greatest tension is produced with a longer moment arm.

How does fiber-type distribution of muscle type 1(slow twitch) and type 2A&B(fast-twitch) affect tension generation of skeletal muscle?

High percentage of type 1 fibers favors low force production, slow rate of max force development, resistance to fatigue. High percentage type 2A&B fibers favors rapid high force production and rapid fatigue.

What does the overload principle state?

If muscle performance is to improve, load that exceeds the metabolic capacity of the muscle must be applied. Muscle needs to be challenged to perform at greater levels. Muscle can adapt if external force is constant.

What is endurance training?

Is the systematic practice of using muscle force to raise, lower, or control a light external load for many reps over an extended period of time.

What determines an appropriate resistance program?

It all comes back to our IE. This is how we know what the patient will need. Are they post op? are they younger? Chronic, subacute?

What is the exercise order that should be taken in a single sessions?

Large muscle groups before small muscle groups. Multijoint exercises should be performed before single joint. After w/u higher intensity exercises should be performed before lower intensity exercises.

What is occurring during isokinetic contractions?

Limb velocity is held consistent by a "rate controlling" device.

How do you progress repetitions and sets?

Low volume to high volume

What are key parameters for endurance training?

Low-intensity muscle contractions, high number of repetitions, prolonged time period.

With age, what has a stronger relationship to functional limitations and disability? Muscle strength or muscle power?

Muscle power, decline in muscle movement = decline in muscle power generation. (ex. rising from a low chair or making balance adjustments)

How are velocity and force related during a concentric muscle contraction?

Muscle shortening velocity increases and force of muscle decreases.