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102 Cards in this Set
- Front
- Back
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Motor Unit
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motor neuron and all the muscle fibers it innervates
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Motor Pool
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The group of motor neurons that innervate one muscle (collection of muscle fibers)
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Do all motor neurons have the same sized cell bodies?
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No, they vary in soma size
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How and why do innervation ratios vary?
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Depends on fine control needed.
One motor neuron innervates 15 muscle fibers in the eye muscles (1:15) First dorsal interosseus muscle (1:340) Tibialis anterior and medial gastrocnemius (1:1,900) |
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What is true about all the muscle fibers of one motor unit?
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They are similar, in terms of oxidative capability, etc.
All type I, or all type IIa, etc. |
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What are the categories of muscle fibers?
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Actually more than three, but most textbooks recognize Type I (slow twitch or slow oxidative), Type IIa (fast oxidative-glycolytic), and Type IIb(or x?) (fast glycolytic)
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How does muscle fiber diameter vary across fiber types?
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Book says Type I is small, IIa are intermediate, and IIb are large
Original studies were in cats, so that doesn't necessarily apply to humans! Studies are mixed, but Type IIa tends to have the larges area in men, while Type I is largest in females. |
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How do structural aspects of muscle fiber diameter, mitochondrial density, capillary density, and myoglobin content vary across muscle fiber types?
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Fiber diameter depends on study and is discussed elsewhere
Mito, capillaries, and myoglobin are high in Type I, intermediate in Type IIa, and Low in Type IIb |
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How do functional aspects of muscle fibers (twitch/contraction time, relaxation time, force production, and fatiguability vary across the fiber types?
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Moving from I to IIa to IIb,
Twitch time: Slow, Fast, Fast Relaxation: Slow, Fast, Fast Force: Low, intermediate, high Fatiguability: Low, intermediate, High |
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How do the metabolic aspects of phosphocreatine stores, glycogen stores, triglyceride stores, myosin-ATPase activity, glycolytic enzyme activity, and oxidative enzyme activity vary across the muscle types?
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From I to IIa to IIb:
PC: low, high, high Glycogen: low, high, high Triglycerides: high, intermediate low Myosin-ATPase: low, high, high Glycolytic: low, high, high Oxidative: high, intermediate, low |
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What are the two different classifications of muscle fibers based on?
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Myosin ATPase classification based on myosin enzymatic activity. I, IC, IIC, IIAC, IIA, IIAB, IIB. measure of contraction speed, most common system of study (so, we need to think in and use the system correctly to understand literature)
Biochemical classification based on fast vs. slow myosin ATPase activity and oxidative and glycolytic enzyme activity. SO, FOG, FG. Best for understanding metabolism, contraction speed, and force, but not widely used to study human muscle |
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Which muscle fibers can generate the most force in a male?
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IIa, based on fiber size and slightly greater specific tension in fast fibers
1 = low, IIB/X = medium |
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How does power vary across muscle fiber types?
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Low in I, intermediate in IIA, High in IIB/X
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What might the force-velocity curve not apply to?
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Movements... the changing joint angle changes the force (how can you have velocity without movement though?)
Curves are generate in lab with tendon pulling in a straight line |
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Work/time =
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Force x distance/time = F x velocity = POWER
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Where does peak power occur?
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At around 30% of 1 RM (not in the middle of max force production)
P = F x V With low force you can generate high velocity and you can generate high force at low velocity, but the power curve is an arc on the FxV graph (x axis, y axis) with a peak around 30% of force |
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In untrained muscle, Type __ fiber produce the greatest power due to ____
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Type IIB, dramatically highest velocity
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What do the force-velocity and force-power curves look like for a multi-joint movement, such as the bench press?
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As load is reduced, velocity is increased, basically linear, not hyperbolic
Power curve is pretty flat, increases slightly with more force, maintains, and decreases again at high force (i.e. maximal power output is similar across a wide range of load and speed combinations) |
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Are all 3 fiber types found in all muscles? proportions?
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Yes!
Average of muscles is about 50% fast 50% slow, but varies across muscle types Large limb muscles 40-60% Type I in typical people Orbicularis oculi - 85% fast Soleus - 80% slow People aren't all the same. Sprinters are mostly fast fibers while endurance athletes are mostly slow |
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Can you change your % fiber types?
With endurance exercises? |
Much is determined by genetics, but endurance exercise increases oxidative capacity of trained fibers, thereby increasing % IIA or IIAB and decreasing % IIB as IIB fibers change to express IIA myosin and increase oxidative capacity (ONLY for INTENSE endurance training, low intensity barely activates Type II fibers)
Also, atrophy of type I, IIa, or IIb fibers may occur. Due to loss in myofilaments - can't have large highly aerobic muscles Happened to young athletes preparing for a marathon, and in long-term long distance runners |
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Can you change your % fiber types.... with strength/power exercises?
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All fiber types hypertrophy, but greatest in fast fibers
Increases %IIa (and/or IIAB) and decreases or complete loss of % IIB fibers "The IIx fibers have disappeared if you have recruited them" IIX to IIA fiber conversion occurs for either intense endurance training or resistance exercise (training doesn't lead to more IIA, but less IIb Most studies conclude that exercise doesn't change % fast and slow muscle fibers |
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Can strenght/power exercise cause hyperplasia due to splitting of existing muscle fibers or new fiber formation from satellite cells?
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No! No change in total number of fibers has been shown with exercise, and fibers don't split in two
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How does hypertrophy occur?
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Increase in cytoplasm requires satellite cells to migrate into the cell to become myonuclei because there's a set cytoplasm:nuclei ratio (each nucleus can only control a certain volume), and new myofilaments are added
Satellite cells aren't fully differentiated, so they have the potential for a couple things Some talk about satellite cells forming a new muscle fiber - this does happen when a deep cut kills muscle fibers. Satellite cells are stimulated to multiply and fuse to form new fibers, but the stimulus is trauma, not exercise so there's no trick to getting more muscle fibers |
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What is the effect of genes and what's the potential effect of training (i.e. typical environmental influences) for height, length of arms?
For muscle fiber composition? For mitochondria/gram of muscle? For muscle size? For aerobic endurance? |
Height: Genes - large, Training - small
Fast v slow twitch: large, small Mitochondria/gram: small, large (train it up!) Muscle size: large, small (on the global spectrum, a 50% increase is huge!) Aerobic endurance: moderate to large, small to moderate (many organ systems involved, training effect on muscle enzymes doesn't have a large effect overall) |
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What happens when someone trains for endurance and strength/power at the same time?
Who should be concerned with this? |
Endurance training inhibits resistance adaptations, while resistance training doesn't impair endurance adaptations
So baseball players need speed/power interval training, not endurance ~10% loss of resistance training adaptations Why? Satellite cell response to resistance exercise is blunted when immediately followed by aerobic, conflicting signals and aerobic wins, can't have it all! Elite strength/power athletes want highest peak, but most people benefit most from both, periodization allows you to get the most from each |
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Can non-exercise stimulus change % muscle fiber types?
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Yes. (infant and elderly aging, immobilization, muscle or nerve injury, spinal cord injury, polio, space flight)
% Type II decreases with age Fast twitch increases in space Polio increases Type I In a cast, Type I converts to Type II With spinal cord injury, must exercise to combat fatiguability |
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How should you answer a question regarding fiber types sizes, and properties?
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For NSCA or other standardized test, size moves from small to large, power from low to high
In 416, IIA is largest in men, Type I in women (makes sense that IIb wouldn't be the largest, because they're lost with exercise) |
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What does the brain do to increase muscle force?
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Turns on motor units of a muscle pool using orderly recruitment, more tension needs more units
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What is motor unit recruitment based on?
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motor neuron size
smallest motor neuron recruited first, next biggest next...etc. Principle of size recruitment (size = size of motor neuron soma, not muscle fiber) Each motor neuron innervates muscles of the same type |
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What are the sizes of motor neurons
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Type I are small
Type IIa are medium Type IIb are large |
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How is input to a motor neuron pool distributed to the motor neurons in the pool
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goes equally to every motor neuron, but if it's a weak command only the small ones are sensitive enough to respond. With greater force/command, bigger units respond
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Can you selectively recruit fast twitch motor units for ballistic contractions?
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no, recruitment order is the same (from Type I to IIa to IIb), but all can be recruited virtually simultaneously
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Once a motor neuron is recruited, does it fire at the same rate for the rest of the time
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no, starts at a slow rate and increases up to the max (graph of increasing stages, like wedge hills)
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Force production of a muscle can be increased by:
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1. recruitment of additional motor units and
2. summation of twitch forces (rate coding) |
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Explain summation
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rate coding of muscle force
each muscle action potential produces one muscle twitch (from a little release of calcium), when APs are widely spaced, the tension from one twitch decays to zero before the next When they occur more frequently, the force from each one adds on to the last (greater intramuscular Ca++ concentration) Greater summation with higher rate of APs |
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What is the explanation for superhuman feats of strength?
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they are urban legend, there's always a biomechanical reason (not that they suddenly produced huge forces)
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Comparing walking, running, and jumping, what is the power, recruitment level (% of motor pool), and muscle fibers utilized (which types)
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Walk = low power, 35% recruitement, type I (slow twitch)
Run = medium power, 50% recruitment, Type I, Type IIa Jumping = high, 98-100% of pool, Type I, IIa, IIb |
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Are type I fibers used in a sprint?
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Yes, recruited first, but always used
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Will recruiting all fibers and producing a maxiumum voluntary effort create enough force to break your bones?
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No! golgi tendon organ inhibits force production. Even if you're activating all, not necessarily firing at max rate
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How much do type I fibers contribute to a sprint (assume 45% type I fibers
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about 18% (see line on that graph that we talked about for a while), most comes from type II
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How do recruitment and summation work together as force produced by a muscle increases?
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Motor units are recruited and then fire at higher frequency
(graph with different shading for level of force produced) |
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When you go jogging, how much of your muscle is being activated and stimulated to adapt?
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about 20% (the other 80 doesn't adapt)
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What % recruitment does a sedentary person typically use?
% motor neuron recruitment? % muscle mass activation? |
neuron = <25% about 12% average throughout the day
Muscle mass = ~ 5% |
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How does muscle area change over the lifespan?
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# of fibers starts decreasing at around age 30, curve of muscle area drops off with age
Type I don't really atrophy much, but Type II do Old people don't have big type II fibers, and recruitment curve changes over the lifespan |
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How does motor unit recruitment change with atrophy?
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As muscle atrophies, it becomes necessary to recruit a greater percentage in order to produce the same force needed for a task
50% reduction in force production capacity |
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How does an effective strength training program for 74 year olds compare to one for 22 year olds?
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Climbing stairs and getting out of chairs can provide sufficient stimulus (78-89% of maximum leg press effort), though it would be too easy for young (42-54% of max)
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elderly men who have been involved in life-long endurance training compare to their peers how?
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They have high aerobic power, but similar muscle strength to non-active elderly men (running doesn't use fast-twitch fibers)
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How did the muscle strength of runners compare to that of non-athletes in a study by Trappe?
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Fibers generated less peak force, 15% weaker, strength per fiber size was the same, so it was because of the smaller size of the cells
Elevated shortening speed of the runners' fibers was insuficient to overcome the deficits in strength to equal the power characteristics of the sedentary control fibers |
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After all this bashing on running for making people weaker, why did aerobically active elderly individuals have greater absolute and relative strength than sedentary?
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Authors speculate it was because they did multiple modes of aerobic exercise, mostly not running - cycling, rowing. Forces in cycling and running have a force exerted over a period of time, with running is sporatic
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In a non-isometric task, what determines the % of muscle recruited?
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Power output, not load lifted
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What to self-selected resistance training loads tend to be?
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for both genders, too low! below 60% 1 RM, not sufficient intensity to induce hypertrophic responses and subsequent strength increases
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How does resistance training with a personal trainer affect the workout
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leads to greater initial 1 RM strength values, self-selection of greater workout intensities, and greater ratings of perceived exertion
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At what age do you need to start exercising to be as fit and functional as possible?
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Best answer: exercise throughout your whole life!
Must do high power/intensity/loading starting by age 25 in order to sustain force producing capability when older People who exercise will still decline with age (loss of type II fibers) but still fitter than people who put off exercise until later in life (started at 45 of 56) |
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Does electrical stimulation of a muscle contribute to strength gains?
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In healthy people, it doesn't produce significant muscle force (low recruitment and lack of force generation, small % of fibers and motor units) and so doesn't add to strength gains from a strength training program
For injured people, it does maintain muscle mass when a voluntary training program is not possible, if done correctly (sufficient recruitment and loading) |
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Do you need to life big weights to get big muscles? What about doing a lot of reps in order to activate the whole motor pool?
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When lifting 50% of 1Rm, you start out only activating around 50% of the motor pool, but by the 12th rep some have started fatiguing so you have to recruit more. Can end up recruiting all fibers, but the effect is not the same. (stimulus from 12 lb 10 times vs. 50 lb 6 times)
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Is jogging with weights a good way to combine aerobic and strength training?
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Not much effect on fiber recruitment (if you can still maintain for 20 min)
But, remember that moderation is fine for endurance, you just have to work hard in resistance! |
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What advice should you give to people who want to be healthy?
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Variation! don't just run (also bike, row...)
1st, add any exercise (likely aerobic will be chosen) 2nd, add in resistance training Then balance training and hopping (bones) |
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What changes occur to make someone stronger when she weight trains?
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Strength gains are not proportional to muscle size (CSA) increases
The strength increases that occur in the first few weeks precede increases in muscle mass Muscle mass typically takes up to 8 weeks to increase significantly |
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What happens to the other limb in a unilateral strength training program?
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The contralateral limb becomes stronger even though it was not working out.
It does not gain any muscle mass... the bilateral transfer is neuromuscular |
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In a test where someone trained with a free squat and tested knee extensor force in several exercises, why was there less of an increase in force in the different testing conditions?
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His 1RM for free squat increased by 70%, seated squat machine increased by 30% and other seated machine didn't have significant increases
Must develop joint coordination in order to exert force Pelvis/back have different positions and roles Must learn the specific movement pattern |
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What neural adaptations occur with resistance training?
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1. Increased maximum EMG level seen, some studies in which Max Voluntary Contraction strength increases with training due to increased motor unit firing frequency
2. Increased rate of rise of EMG at start of force development (increased doublets) 3. Reduction in the antagonist coactivation 4. Multijoint/multimuscle coordination for posture and stabilization 5. Proposed: increased recruitment of more motor units - healthy people can recruit all for max contraction 6. Proposed: increased synchronization of motor units firing, found in some studies but not all. Synch has not been demonstrated to increase muscle force. 7. Proposed: enlargement of the neuromuscular junction ("functional significance unknown") 8. Proposed: reduction in GTO inhibition of muscle activation. Rubbish, does not occur |
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Neural adaptations:
1. increased max EMG level seen in some studies in which MVC strength increases with training, due to increased motor unit firing frequency, produces higher max force from muscle. INcreases in neural drive are observed to be greater for lengthening contractions than shortening. But... |
a. Not all training studies show increased EMG with strength increases
b. Increases in motor unit firing frequency with training has been found in only some studies c. increases in maximal effort motor unit firing frequency with training has been found to be much higher in elderly and moderately higher in young adults Or has been found to occur in young but Not in elderly d. The use of surface EMG to measure muscle activation level (neural drive) has recently been questioned |
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What percentage of MVC force effort is required before you get 100% recruitment?
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85% (but low firing rate in largest motor units)
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Neural adaptations:
2. Increased rate of rise of EMG at start of force development (increased doublets) |
Increased rate of rise of EMG at start of force development (increased doublets in motor unit firing at start of contraction, lower recruitment threshold for motor units so they are recruited earlier as force is increasing, produces increased maximum rate of force development
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Neural adaptations:
3. Reduction in the antagonist coactivation |
Reduction in the antagonist coactivation allows prime mover torque to not be counteracted by antagonists. (remember: coactivation of agonist and antagonists will work against each other and reduce the net torque (force) output from an agonist prime mover, but:
a. Reduced coactivation is observed in the elderly (stiff, too much cocontraction, most stable but least efficient) b. Reduced coactivation was observed in an isometric contraction in young subjects in which there was no increased EMG of the prime movers c. Some studies find no decrease in antagonist activation with resistance training What does all this mean... this might not be an important adaptation? |
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Neural adaptations:
4. Multijoint/multimuscle coordination for posture and stabilization |
4. Multijoint/multimuscle coordination for posture and stabilization. e.g., hip, knee, ankle, trunk, contralateral leg, and arm muscle activation coordination for leg extension during kick
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Neural adaptations:
5. increased recruitment of more motor units |
5. Proposed: increased recruitment of more motor units - healthy people can recruit all for max contraction
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Neural adaptations:
6. increased synchronization of motor units firing, |
6. Proposed: increased synchronization of motor units firing, found in some studies but not all. Synch has not been demonstrated to increase muscle force.
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Neural adaptations:
7. enlargement of the neuromuscular junction |
7. Proposed: enlargement of the neuromuscular junction ("functional significance unknown")
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Neural adaptations:
8. reduction in GTO inhibition of muscle activation. |
8. Proposed: reduction in GTO inhibition of muscle activation. Rubbish, does not occur
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At what point to the lines for % of improvement due to neural factors and for % of improvement due to hypertrophy factors cross in a graph for a healthy young male over training time? For a elderly lady? For a college-age female?
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For a healthy young male, hypertrophy factors account for an increasing % of improvements while neural factors decrease in percentage until they cross around 12 weeks of training
Elderly ladies don't bulk up much... lines would go toward each other a bit, but stay mostly stable, with neural factors contributing the greatest % College age females don't hypertrophy much either, so lines probably wouldn't cross, though they would become closer than for the old lady. ~75% neural |
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What happens to the % improvement due to neural and hypertrophy factors in a healthy young male after long-term training? (104 weeks)
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After the plateau in hypertrophy, athletes train muscle activation, so neural factors may improve again and become responsible for a greater % of improvement again (possible)
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How was the correlation between strength of isolated muscle groups and functional performance (e.g. stair climbing, rising from a chair, balance, 6 min walk time)
In study of older adults at WWU |
very weak to moderate correlation
machines are related to specific muscle mass, but lack multijoint coordination and proprioception Elderly have 90-100% neural adaptations (not hypertrophy) |
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What's Chalmers' list of things that improve (strength?) performance?
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Hypertrophy - bigger cross-section
Neural adaptations: Rate of firing (doublets: AP close together - rapid rise in force at start of contraction) only important for right at the beginning Increased multijoint coordination Reduction in co-contraction of antagonists Fire active motor units at higher frequency |
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Why do people resistance train?
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exert more force (functional - sport, job, ADL)
look good - cosmetic diabetes - glucose metabolism bone health, psychological, social aspects... In this class, we talk about force production. Not enough to do activities which maximize muscle size, and activities which are task specific, but also at the correct velocity |
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How does an increase in strength transfer at different speeds of muscle movement?
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Slow speed training group showed greatest strength increases at slow speed test
Fast group at fast speed test Middle speed training group was similar at all speeds |
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Does heavy resistance training increase the rate of force development and EMG onset?
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Not really, Explosive training did though
Steeper slope in those who trained explosively |
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What did the study on kayak sprinter training reveal?
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For the first 3.75 m (acceleration phase), the slow training group improved most, for the last 7.5 m (sprint), the explosive training group improved the most, but barely and not as much as slow did in the first section
Conclusions: slow weight training is likely to be more effective than explosive training for improving the acceleration phase of sprinting, when force is hight throughout the length of the stroke, explosive weight training may be more effective in speed maintenance, when forces are developed rapidly over a short period at the start of the stroke |
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What speed should you train at???
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"Data... supports velocity specificity and demonstrate the importance of training at fast, moderate, and slow velocities to improve isokinetic force production across all testing velocities"
But, velocity specificity of training may apply mainly to people who are trained, not untrained people |
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Should we be training muscle strength or power?
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Researchers say:
"in many activities, rapidly developing force is equally or more important than max force itself" "in virtually all situations, an efficient means of activating muscles quickly, or of producing high impulses within given time periods is much more desirable [than basic MVC strength] "in normal human movment, time may be > force, aging leads to greater worsening in explosive force production... power exercises may be usefull" "...muscle power may also be a stronger predictor of fall risk and functional decline... maybe high velocity, low load training for young adults, not sure about elderly" |
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In a study, was power training or strength training more effective for improving physical function in community-dwelling older adults?
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power training!
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In a meta-analysis, was power training or resistance training better for function in elderly persons?
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power training is feasible for elderly persons and has a small advantage over strength training for functional outcomes. no firm conclusion can be made for safety
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Maximum mechanical power is produced at a resistance of what percent of maximum isometric strength, which corresponds to a velocity of muscle shortening of approx. what percent of max?
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at 30% max strength, about 30% of max velocity
Power improvement is greater when training at that speed |
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Though it's best to train at a variety of speeds and loads, if you had to pick one load to train at to maximize power adaptation, what should you choose?
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Train against a 30% resistance - greatest increase in force and power over the entire concentric velocity range
But, NSCA says 30% 1RM can't be trained if using typical resistance training equipment, so: powertraining for single event effort (throw): 80-90% 1RM for 1-2 reps fast for multieffort event (volleyball jumping): 75-85% for 3-5 fast reps |
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If a person is weak or young, should they train for power?
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Work on basic strength before power (and they'll gain power too)
If you train power at low loads, strength and power will decrease (!) Periodization - but even when training power, need some heavy loads for strength maintenance Overall, train the whole curve! (max effort at each point) Rapid bicep curls at 50% feel like no workout, hard to train typical lifts that way |
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Try doing Rapid bicep curls at 50%
feel like no workout, Why is it hard to train typical lifts that way (with high velocity for power) So, how do you train at fast speeds? |
At slow velocity, the muscle is contracting fairly constantly the whole time
At a faster velocity, the muscle shuts off more quickly and you need braking from the antagonists (only firing half the time) Even faster, and the muscle is off for only .25 sec So, use ballistic training, in which you release the mass |
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What is ballistic training?
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resistance training when an athlete throws or jumps with a weight, but does not brake, instead releasing the mass at the end range of motion to promote power and acceleration
(decreases inertia, instead of having to slow down) |
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What are some sample ballistic training methods?
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Plyometrics
Medicine ball training Weighted jump squats, pushups (weight needed?) Speed up typical exercises (up stairs, out of chair, do some typical machine or free lifts faster, for someone slow) Add chains or elastics to some free lifts and do them fast Lift and throw sandbags (weightlifting or other movements) Weightlifting movements (cleans, hang cleans from the knees) Lift and throw and drop weight into sand pit Air resistance (keiser brand) Computerized weight equipment that allows the release of mass |
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What should be done before beginning ballistic resistance training?
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previous strength training should be completed (able to squat 1.5x body weight) before initiating a gradual increase in ballistic resistance training due to theorized protective role in terms of injury prevention
But, simple jumps and hops can be used with most athletes as long as they have demonstrated the ability to land properly |
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What was the Oilers exercise program like?
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Increasing challenge and complexity for nervous system, increasingly realistic movement, -> highest degree of freedom
no machine weights or bilateral movement with 2 hands or feet fixed together, load and often body stabilized for you exercises in multiple planes of movement without hands or feet fixed, unilateral movements |
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What is the concept of bilateral deficit?
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If you can bench press 50 lb dumbbells with each arm, it seems like you'd be able to bench press 100 lb, but you can probably only do 90lb or so.
Based on neural pathways. NS is designed for oscillatory side-to-side movements, 1 side inhibited while the other is active Other way - Bilateral training doesn't transfer well to unilateral movement |
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What happens when you go from bilateral training to unilateral?
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You won't be able to move half of the weight with each arm (or leg)
multijoint coordination is different One side compensates for the other in bilateral loading, and you're not used to stabilization Mike Boyle likes unilateral loading because it decreases load on spine |
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the greater the effort and acceleration with a given weight, the greater the
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power development and subsequent training effect
Peak power output during weightlifting movements (snatch and clean and jerk) is the highest ever documented, and comparable to max theoretically possible in humans. Explosive actions are executed in .2-.3 sec, and peak power production is 4-5 times that of the deadlift or squat, 11-15 times that of the bench press |
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Selection of exercises for strength/power training should be viewed as ___ specific rather than simply _____
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movement specific, "training a muscle(s)"
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What single-joint exercises should be included in a program?
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purposefully selected exercises to work on things that need extra attention (not worked in other exercises, injury, etc.)
Glutes often need attention people are better at activating things further from the spine |
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What is neural confusion? Or, could Roger Federer become a tennis and table tennis champion simultaneously?
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Memory interference can happen at the single neuron level. If the same neurons are involved in tennis and table tennis, then the two tasks will interfere one with the other. If different sets of neurons are used, Federer could be a table tennis champ while maintaining his tennis ranking.
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What were the results of functional task exercise versus resistance strength exercise interventions to improve daily function in older women?
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Functional task exercises were more effective at improving task performance in healthy elderly women
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Top three guidelines for training elderly population
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1. Use bodyweight and free weights whenever possible
2. Increase the load appropriately - 60-80% 1 RM 3. Combine power and strength exercises, lower body power should focus on rapid, concentric movements Any notion that an elderly person needs to be trained differently than a younger adult is simply not the case |
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How do you have "accommodating resistance"?
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"accommodate" the strong and weak point of a motion with bands or chains that alter the resistance throughout the movement
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Top Ten Training Tips for Conditioning Success
First four rules |
1. Bodyweight before external resistance (no sense using load if you can't stabilize, control and move efficiently with you own bodyweight)
2. Train to the 5th Power I. Train in a standing position - ground based II. Train with free weights III. Use multiple joints IV. Train with explosiveness (as fast as possible with control) V. Train movements, not muscle groups 3. Train unilaterally and multi-planar 4. Use all primary methods to develop strength (force production) All three: max strength (heavy loads), repeated efforts method (multiple sets and reps), dynamic effort method (relatively lighter weights and moving them at max speed, still least used method though rate of force development is most important for athletes) |
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Top Ten Training Tips for Conditioning Success
rules 5-10 |
5. Variation (not just increases, but variation in exercises and their order)
6. avoid mimicking skills - not functional to throw weighted baseballs- will do little to improve your strength and a lot to screw up your technique. Swimmers should train opposite motion instead of just doing internal rotation work, have balance. 7. Train with Balance - pushing and pulling motions should use equivalent weights 8. Get out of the weight room (sled dragging, stadium stairs... get outside the box of the room. coordination, balance agility) 9. Train the antagonists - speed is largely determined by ability of antagonist to eccentrically decelerate the joint motion efficiently and prevent joint injury 10. Full Front Squats - may be most athletic exercise - core strength, wrist, knee, hip, shoulder, and ankle flexibility in a single exercise. and one more 10.5 Extension! Explosive triple extension (ankle, knee, hips) is a valuable component when training athletes. Don't confuse gym improvements with real world or sports world improvements. Greatest athletes don't have greatest bench presses. Useable force is force properly directed in an unstable real world, unpredictable environment |
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What's the physiological basis of muscle fatigue? (jumping up and down...)
This isn't on the test. |
Exhaustive stretch-shortening cycle fatigue can dramatically reduce the reflex contribution to force production through deterioration in the sensitivity of the reflex after fatigue because of decreased pH:
- direct inhibition of muscle spindle firing - activating other chemical sensitive afferent nerve endings to act through inhibitory interneuron to inhibit homonymous motorneuron - muscle fiber contractile activity inhibition |
