Throw Away Ch. 5

An increase in voluntary activation of the agonist muscle group occurs, in trained individual. -The EMG activity of antagonist muscle groups has been shown to change in response to anaerobic training during agonist

EMG Study: Bilateral facilitation (Neural Adaption)

The force produced when both limbs contract together is lower than the sum of the forces they produce when contracting unilaterally.

EMG study: Bilateral Deficit (Neural Adaption)

Exercising muscle undergoing unilateral resistance training produces increased strength and neural activity in the contralateral resting muscle.

EMG study: Cross Education (Neural Adaption)

Heavy Resistance Training

Has been shown to reduce mitochondrial density, even though the count stays the same. -Mitochondria and capillary density decrease with hypertrophy.

maximizing the expression of muscular strength and power.

increased neural drive is critical to

Over 16 workouts is required (longer periods of training) before hypertrophy or any significant changes in the CSA occur.

# of workouts before muscle hypertrophy occurs and there are changes in the CSA...

-Other motor unit adaptions include changes in the rate and sequence of firing. -A positive relationship exists between the rate of motor unit firing and the amount of force produced -The increase in firing rate is dependent on muscle size because smaller muscles depend more on recruitment

(1) Other motor unit adaptions include changes in the ____ and _________ of firing. (2) A positive relationship exists between the ____ of motor unit firing and the amount of...

-positive changes in the reflex response of the neuromuscular system and -enhances the magnitude and rate of force development via the reflex (i.e., muscle spindle or streth reflex).

-Anaerobic training causes positive changes in the ______ ________ of the neuromuscular system and enhances the magnitude and rate of ...

· Trained individuals show greater angles of pennation in the-triceps and lats-

-Trained individuals show greater angles of pennation in the...(2), compared to untrained individuals. -Fascicle length has been shown to be greater in strength trained athletes.

-The surface of the skin is numbed , and a needle electrode, or a needle containing 2 fine-wire electrodes, is inserted through the skin and positioned into the belly of the muscle itself. Usually only used in a research or clinical setting. -Fine-wire electrodes emphasize a specificity of assessment in that they are located in a muscle of interest and accurately record localized motor unit action potentials.

2) Intramuscular EMG (needle or fine wire)

-the alpha motor neuron and the muscle fibers that it activates -a motor unit may innervate <10 muscle fibers for small, intricate muscles or >100 fibers for large, powerful trunk and limb muscles.

A motor unit consists of..

high force, speed or power production.

According to the size principle, motor units high in recruitment order are primarily used for...

substantial neural changes in the spinal cord, particularly along the descending corticospinal tracts

Adaptions to anaerobic training methods are then reflected by

Pennation Angle

Affects the force production capabilities as well as the range of motion of a muscle. -Larger ones can also accommodate greater protein deposition and allow for greater increases in CSA. -increased through resistance training

Increases as a means to support heightened levels of force expression.

After use of anaerobic training methods, the recruitment of fast-twitch motors..

-Blood and muscle pH- is reduced through anaerobic exercise

Anaerobic exercise significantly reduces (1 level in 2 places)

phosphagen system; they are usually less than 10 seconds in duration and minimize fatigue by allowing almost complete recovery between sets (e.g., 5-7 minutes).

Anaerobic exercises such as sprints and plyometric drills primarily stress the

higher brain centers and continuing down to the level of individual muscle fibers.

Anaerobic training has the potential to elicit long-term adaptions throughout the neuromuscular system, beginning in the

-The summation of overlapping action potentials. -With increased motor unit firing rates, the muscle fibers are continually activated by subsequent action potentials before they have time to completely relax following a prior action potential. -These firing rates represent an adaptive mechanism shown to improve following heavy resistance training

Augmented Contractile Strength

-increased agonist (i.e., the major muscles involved in a specific movement or exercise) muscle recruitment, -improved neuronal firing rates, and, -greater synchronization in the timing or -neural discharge during high-intensity muscular contractions.

Augmented neural drive is thought to occur via (4)

Hypertrophy involves an increase in the net accretion of -actin & myosin -within the cell -as well as an increase in the number of -myofibrils- within a muscle fiber. -other structural proteins such as -titin & nebulin- are also synthesized and added to the periphery of the myofibril which results in an increase in its diameter. --The effect of these additions is and enlargement of the fiber and, collectively, the size of the muscle or muscle group itself.

Biologically, hypertrophy involves: -an intracellular increase in the net accretion of contractile proteins....(2) -as well as an increase in the number of ___________ within a muscle fiber. -In addition to the contractile proteins, other structural proteins such as _____ and _______ are also synthesized. The new myofilaments are added to the periphery of the myofibril and result in an increase in its diameter. -The effect of these additions is and enlargement of the fiber and, collectively, the size of the muscle or muscle group itself.

-greater neuromuscular activity increases EMG activity -the onset of hypertrophy is associated with a decline in EMG activity.

Causes an Increase in EMG signal indicates Causes a decrease in EMG activity

all the energy systems and demonstrates how each of them contributes to a varying extent in order to fulfill he global metabolic demands of competition.

Competitive sports requires the complex integration of

-Electromyography -is a common research tool used to: examine the magnitude of neural activation within skeletal muscle. -2 kinds of EMG are: Surface EMG & intramuscular EMG (needle or fine wire)

EMG: What it stands for, what it does, and the two types

-Increase -Increases -Type II fibers -fast-twitch

Fiber Size Changes: -Resistance training shows an increase/decrease occurs in both muscle fiber types. -Type I and II fiber area increases/decreases -There are greater increases with the Type.....fibers Athletes who genetically possess a relatively large proportion of fast-twitch/slow-twitch fibers may have a greater potential for increasing muscle mass

(a) an increase in recruitment (b) an increased rate of firing (c) greater synchronization of neural discharge (d) a combination of all these factors.

Gains in maximal strength and power of agonist muscles are generally associated with (a), (b), (c), or (d)

Sprint Training

Has been shown to -enhance calcium release which increases speed and power by promoting actin and myosin cross bridge formation.

Resistance Training

Has been shown to increase -myofibrillar volume -cytoplasmic density -sarcoplasmic reticulum and T-tubule density -sodium-potassium ATPase activity. Collectively, these changes act to facilitate hypertrophy and increase strength

Hyperplasia: Term given to an increased number of muscle fibers via longitudinal fiber splitting in response to high-intensity resistance training. (may increase muscle size, not studied enough)

Hyperplasia: (define)

The enlargement of muscle fiber CSA following training. -positive correlation with muscular strength (but does not

Hypertrophy

electrical stimulation

In untrained individuals or individuals recovering from injury, ___________ ____________ has been shown to be more effective than voluntary activations in eliciting beneficial gains.

consecutive muscle contractions, whereby action potentials temporarily overlap. (Augmented contractile strength)

Increased force with greater firing rates reflects the summation of...

higher brain centers, where the intent to produce maximal levels of muscular force and power

Increased motor unit activation begins in the

physiological adaptions that determine performance

It is critical that the appropriate anaerobic training be programmed and prescribed in such a way to optimize the

muscular strength, power, hypertrophy, muscular endurance, motor skills, and coordination are all recognized as beneficial adaptions following anaerobic training; These include resistance training; plyometric drills; and speed, agility, and interval training.

Long-term adaptions that occur in response to anaerobic training are specifically related to the characteristics of the training program. For example improvements in...(7)...and include ___________ training i.e., (3)

glycotic; high-intensity exercise; The integration of high-intensity exercise with short rest periods is considered an important aspect of anaerobic training, as athletes are often required to perform near-maximally under fatigued conditions during competition.

Longer-Duration interval-type anaerobic training predominately using energy production from the ________ system, in which shorter rest intervals (e.g., 20-60 seconds) are adopted during

optimal neural recruitment for maximal performance (and high-quality training).

Many anaerobic training modalities emphasize the expression of muscular speed and power and depend greatly on

1) recruitment of the highest percentage of available motor units (high-threshold motor units) 2) high frequency recruitment -Once a motor unit is recruited, less activation is needed in order for it to be recruited.

Maximal force production: 2 requirements

Mechanical stimuli: -heavy lifting, using eccentric muscle groups, moderate or high training volume. (strength training)- -Result in: --optimal growth factor expression --recruitment of muscle fibers --disrupt sarcomeres. ---All increase CSA.

Mechanical stimuli: (define) -Result in...(3)...all which...

Metabolic Stimuli: low-to-moderate-intensity or moderately high intensity training with high volumes and short rest. (body building training) -Glycotic

Metabolic stimuli: (range of intensity, level of volume, and amount of rest ) Stress the __________ energy system and increase metabolites that help muscle growth. Cause anabolic protein growth.

Collectively, these adaptations result in enhanced performance characteristics that include: -strength -power -muscular endurance all of which are critical to athletic success.

Muscle adaptions: enhance performance characteristics that include...(3)...all of which are critical to athletic success.

IIx, IIax, IIa, IIac, IIc, Ic, I -the least oxidative to the most oxidative type-

Muscle fiber continuum: -least oxidative to most oxidative-

Pennate Muscles

Muscles that have fascicles that attach obliquely to its tendon. (in a slanted position)

Myogenesis: When muscle fibers contract, Akt/mTOR signaling increases dramatically -this response is critical for increasing -protein synthesis and growth-

Myogenesis (define) -this response is critical for increasing ...(2)

-meeting point between the motor nerve and skeletal muscle fibers. -possible site for neural adaption following anaerobic training. -studies suggest that anaerobic training creates helpful morphological changes in the NMJ that help neural transmission capabilities.

NMJ -Meeting point for... -possible site for...

Neural Adaptions: improved motor learning and coordination -predominate in the early phase of training without any associated increases in muscle hypertrophy.

Neural Adaptions (define); Predominate which phase of training.

optimizing athletic performance

Neural Adaptions are fundamental to..

-Strength gains in programs that use high training intensities (>85% of 1RM) -Training programs designed to elicit muscular power also provide a potent stimulus to the nervous system and result in higher post training EMG activity.

Neural factors are especially important for...

-accommodation-to the training load occurs. -However, if an athlete incorporates new variation or progressive overload into the training plan, neural adaptions will once again contribute to the performance improvements by acting to tolerate the "new" physical insult from training.

Occurs when muscle hypertrophy eventually starts to plateau... -what can be done to keep improving neural adaptions to contribute to athletic performance

Changes to nervous, muscular, connective tissue, endocrine, and cardiovascular systems.

Physical and physiological adaptions following anaerobic training examples (these adaptions enable athletes to improve athletic performance standards) (5)

lower capillary densities than control subjects, whereas bodybuilder have capillary densities similar to those of nonathletes.

Powerlifters and weightlifters show significantly lower __________ densities than control subjects, whereas bodybuilder have densities similar to those of non-athletes.

rises, or when a new exercise or movement is being learned, in an effort to support the enhanced need for neuromuscular function

Primary motor cortex is elevated when the level of force developed

Protein Synthesis Sequence (a)water uptake (b)noncontractile protein synthesis (c)contractile protein synthesis -At the same time, reduced degradation acts to maintain the size of fibers y reducing net protein loss.

Protein Synthesis Sequence: (a)(b)(c)

to lift a given load.

Research has shown that as muscle size increases it does not require as much neural activation

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Research has shown that only __% of muscle tissue is activated during maximal efforts un untrained populations

(1) carbohydrate and protein intake (2) amino acid availability (3) timing of nutrient intake (4) mechanical stress of the workout (5) muscle celly hydration levels (6) anabolic hormonal and subsequent responses

The magnitude of increased protein synthesis depends on a variety of factors including...(6)

-An exception to size principle; when an athlete is able to inhibit the lower-threshold motor units and activate higher-threshold motor units in their place. -Critical when force production is required at very high speeds for the expression of muscular power. -Beneficial to explosive exercise. (i.e., it would be tough for an athlete to generate enough angular velocity and power to hit their max vert. if they had to recruit their entire slow-twitch motor pool before activation of the fast twitch units.)

Selective recruitment

-Requires placement of adhesive electrodes on the surface of the skin where they are able to monitor a large area of underlying muscle. -Surface EMG is often more effective for monitoring superficial muscle, as it is unable to bypass the action potentials

Surface EMG: What it does and what it is more effective for

The involuntary elastic properties of the muscle and connective tissue -Acts to positively increase force production without any additional energy requirement. -Resistance training has been shown to increase reflex potentiation by 19% & 55%; Furthermore, resistance-trained athletes are found to have greater reflex potentiation in the soleus muscle compared to untrained individuals.

The Myotatic reflex controls...

Motor unit

The functional unit of the neuromuscular system

the training stimulus and the manner in which the acute training variables are prescribed

The magnitude of hypertrophy depends on

maximize mechanical and metabolic stimuli

To optimize muscle growth, you need training periodization to maximize

Type -IIx- fibers represent a "reservoir" that upon consistent activation, changes into a more -oxidative- form along the continuum. (i.e., to an intermediate fiber Type IIax and then to a IIa)

Type ___ fibers represent a "reservoir" that upon consistent activation, changes into a more _________ form along the continuum.

-Size to produce high levels of force- -In advanced lifters, the central nervous system may adapt by allowing them to recruit motor units in a nonconsecutive order. - Recruiting larger motor units first allows for greater production of power or speed in a movement.

With heavy resistance training, all muscle fibers get larger because motor units are recruited in a sequential based on their... (unless)

From type IIx to IIa -meaning they become moe oxidative (from a change in the myosin ATPase)

With training and activation of the high-threshold motor units, there is a transition from Type... to...fiber type. -become more...fibers (not a type, a characteristic)

supercomposition effect

Within skeletal muscle, substrate content and enzyme activity represent further areas of adaption in response to anaerobic training. Most notably, when ATP and creatine phosphate (CP) concentrations are repeatedly exhausted following bouts of intermittent high-intensity muscular contraction, the storage capacity of these high-energy compounds is increased via a "___________________" effect.

anaerobic alactic system

also known as phosphagen or creatine phosphate system. 1/2 of the anaerobic system.

anaerobic lactic system

also known as the glycolic system

-motor units are recruited in ascending order according to their recruitment thresholds and firing rates. -Governs the recruitment or decruitment of motor units in an orderly manner. -Represents the relationship between motor unit twitch force and recruitment threshold.

· Size Principle: -what it states - what it governs - relationship it represents

-All the available motor units must be activated within a muscle -Change in the firing rate or frequency also affects the ability to generate force.

· When expression of maximal force is desired.

Anaerobic Training

•Characterized by high-intensity, intermittent bouts of exercise •Requires ATP to be regenerated faster than the aerobic energy system is capable of •works in the absence of oxygen and includes the alactic system and the lactic system