4.2: Contraction Types, Overloads and Force Delivery Flashcards
Normal dumbbell, barbell, and bodyweight exercises where resistance training involves joint flexion and extension with each repetition; external resistance does not change
Dynamic Constant External Resistance (DCER)
Where external resistance is variable (seen on machines with cams that change radius, or curvilinear type machines. (ex: lateral raise with a dumbbell, experiencing horizontal movement at beginning to vertical movement at 90deg at the end)
Dynamic Variable External Resistance (DVER)
This type of contraction causes more strain on the tendon because the muscle is actually contracting while lengthening so the tendon is pulled from both ends.
Isotonic eccentric contraction
What is experienced often after isotonic eccentric contraction training?
DOMS (delayed onset muscle soreness)
This type of contraction helps you develop extreme strength and literally means “same length”
isometric contraction
This type of contraction literally means “same speed” which requires expensive equipment which alters the resistance quickly in order to maintain speed.
isokinetic contraction
During isokinetic contractions the ________ can vary but the _______ stays the same.
tension; speed
Isokinetic training has been shown extremely effective for _______
speed and power sports; rehabilitation
Training that uses explosive jumps and bounding for developing power—-using eccentric contraction to tighten tendon and rapid concentric utilizing the tight tendon has high risk of injury
Plyometric training
Isotonic contracton is good for what type of performance gains?
strength and power
What stays constant in isotonic contractions?
the weight/tension
What varies and is measurable with isotonic contractions?
speed/repetitions
What stays the same with isometric contractions?
position of the joint
What varies/measurable with isometrics?
tension (true max)
What type of performance gains do you get with isometrics?
strength
What stays constant with isokinetics?
speed of movement
What varies/measurable with isokinetics?
force/tension and reps
What are the performance gains with isokinetics?
power and speed
What are the 3 muscle fiber types?
red, slow twitch (Type 1); red, fast twitch (Type 2a); white, fast twitch (Type 2b)
Breaks down ATP for energy
myosin-ATPase
The more myosin-ATPase in the muscle fiber the _____ and more ______ the contraction.
faster; powerful
Thicker __________ (insulation) enables a faster signal to travel down an axon.
myelin (during myelination process)
a single motor neuron plus all the muscle fibers to which it connects
motor unit
Motor units are triggered to contract through ___________
nerve innervation
Which type of muscle fibers have the fewest amount of mitochondria, restricting the duration of contractions?
White, fast twitch (Type 2b)
Which type of muscle fibers have the most amount of mitochondria, allowing for contractions that last the longest?
red, slow twitch (Type 1)
Oxygen-rich blood is delivered to the muscle cell by a very small tube called a ________
capillary
Which muscle fibers have the largest number of capillaries? Known as “fatigue resistant”
red, slow twitch (Type 1)
Which muscle fiber does not have as much myosin-ATPase and generate less tension?
red, slow twitch (Type 1)
This muscle fiber has fewer capillaries and must rely on __________ to breakdown glucose by enzymes for energy.
white, fast twitch (Type 2b); the process of glycolysis breaks down glucose into ATP for energy
“fast-glycolytic fibers”
white, fast twitch (Type 2b)
There are many, larger fibers in which type of muscle fibers?
White, fast twitch (Type 2b)
Which muscle fibers can use both oxidative (aerobic) or glycolytic (anaerobic) metabolic pathways?
red, fast twitch (Type 2a)
Which muscle fibers are called “fast oxidative fibers” and believed to contribute to the success of long distance runners?
red, fast twitch (Type 2a)
Which muscle fibers contain the fewest and thinnest fibers?
red, slow twitch (Type 1)
Fast twitch muscles are ______ and _____ producing muscles.
power; speed
Slow twitch muscles are _______ producing muscles.
endurance
Which type of muscle fiber would be best for speed and strength; best for strength events
white, fast twitch
Which type of muscle fiber would be best suited for sustaining a load over a long period of time? (stamina) (boxing, football, basketball)
red, fast twitch
Which muscle fiber would be best suited for endurance?
red, slow twitch
Which muscle fibers have many mitochondrial capillaries?
red
What type of fatigue does red, fast twitch have?
Lactate build-up
What type of fatigue does red, slow twitch have?
energy/mitochondrial
What type of fatigue does white, fast twitch have?
Myofibril/ATP
(however they still produce a high amount of lactic acid)
What is optimal rep range for red, slow twitch?
20-25
What is optimal rep range for red, fast twitch?
12-15
What is optimal rep range for white,fast twitch?
(4-6)
What is the muscle structure from smallest to largest?
Actin & Myosin (myofilaments);
Myofibril (sacromere segments);
Muscle fiber (myocyte: cell found in tissue);
Muscle bundle/fascicle (motor unit);
Muscle belly;
Entire skeletal muscle
Only the minimum number of motor units required to move an object will contract (T/F)
True
Light resistance exercise is best for optimizing muscle growth (T/F)
False
How can you ensure earlier “recruitment” of white, fast twitch motor units?
Immediately providing heavy resistance
How does depleting energy recruitment work?
First, red fast twitch units assist the already working red slow twitch. Then white fast twitch are used.
What is the waste build up called in a muscle?
lactic acid
Depleting energy recruitment results in increased _______.
Muscle energy storage
What is contractile speed recruitment?
Based on the speed of a contraction; in theory, red and white fast twitch will be called upon due to their fast contractile speeds
What is Ballistic Training?
“compensatory acceleration training”—olympic style or “power training”: where an athlete lifts, accelerates, and then immediately releases the weight, forcing the recruitment of fast twitch fibers
What is the tendon stretch reflex designed for?
A protection, not requiring processing in the brain or central nervous system. They only follow a path in the reflex loop which only goes to the spinal cord level.
What is Proprioceptive Neural Facilitation (PNF) stretching?
Stretching using the reflexes when contraction occurs and there is a reflexive relaxation of the antagonistic muscles.
Example: Contracting quads while stretching hamstrings
In the brain/spinal cord, the closer region is to the surface of the skull the _____ advanced the function serves.
more
Outer regions of the brain/spinal cord are called the _________ regions.
cortical
The middle ares of the brain/spinal cord are called the _______ regions.
medullry
The deepest regions of the brain/spinal cord are ________ brain and brain stem regions
primative
What protects against too much contractile force?
(GTO) golgi tendon organs
What is a GTO?
golgi tendon organ: proprioceptive sensory nerve ending in the fibers of a tendon (a reflex in the motor units)
If there is too much muscle tension the golgi tendon organ will inhibit the muscle from creating any force, thus protecting the you from injury
What does a GTO do?
shuts doen muscle contraction just short of serious acute muscle injury related to extreme overload
What do muscle spindles do?
They are stretch receptors that act by causing a contractile response in the muscle just short of over-stretch.
They prevent stretching injuries and joint dislocation.
Do major nerve tracts regenerate?
No
What is a neuromuscular unit?
the muscle and nerves that serve it
What is the motor neuron?
a nerve cell located in the spinal cord: axon carry signals/info away and dendrites receive messages.
What is a motor unit?
The entire structure consisting of motor neuron and muscle fibers that it innervates
What do nerves do?
Connect spinal column to the muscle
What does the axon release into the synapse to stimulate the sarcolemma?
Acetylcholine
Summarize the muscle contraction process
1) Motor nerve cell (neuron) carries stimulus to motor end plate
2) Acetylcholine crosses neuromuscular junction and stimulates release of calcium in the cell.
3) This triggers troponin and tropomysin (proteins)
4) Cross bridges pull myofilaments over each other, shortening the length
5) One neuron may innervate hundreds of muscle fibers at once
6) Motor Unit activated (unit of muscle fibers activated)
Fine control over the muscle (fine movements) involve ______ muscle fibers innervated by one neuron.
less
heavier weights use white fast twitch which fatigue quickly and need more time to recover. You may feel _______ but your ____________ needs time to recover.
non-exhausted aerobically; neurologic system
All the tissue fibers within a motor unit will contract together because the same neuron stimulates the entire unit (T/F)
True
You should perform a variety of strength training movements to stimulate a unique adaptive size and strength effect from different angles (T/F)
False
How should strength training movements be selected?
Ones that allow the target muscles to be stressed by the heaviest amount of weight possible, calling upon the greatest number of motor units possible.
What type of movements are preferential to use for optimizing size and strength increase?
compound movements
Is it possible to shape a muscle?
No, muscle structure and shape are strictly genetic
Is “strict” isolation of one muscle or group possible?
No, there are always at least two muscle groups involved in every movement.
Why is “the pump” not an effective method for size and strength?
It inhibits contractions, causing failure prior to optimally damaging the myofibrils, which is required for growth.
What is the “the pump” good for?
In the long run, allows for enhanced blood flow and provision of oxygen and nutrients aiding in more efficient recovery
What is “the pump”?
The blood flow against the working muscle cells blocks removal of waste and lactic acid.
The cell membrane is impermeable during contractions, keeping the lactic acid from escaping.
The contracting muscle tissue builds up lactic acid but also expands causing constriction of blood flow.
The muscle relaxes when finished and rush of blood into working muscles make them appear much larger.
Light, high repetition sets result in ________
energy depletion, recovery fat conversion, and some aerobic conditioning
Heavy, low repetitions result in ________
myofibril damage and growth stimulation
What does momentary relaxation between repetitions do?
Allows for additional oxygen to be taken up by the working muscle fibers.
Why would someone want greater amount of oxygen to be taken up by the working muscle fibers during a set?
The slower the use of the stored muscle glycogen will take place.
What could happen if you take relaxation pauses during heavy intense training?
You may be exposed to hard tissue injury (bones supporting the weight)
What are 3 reasons why a muscle fiber stops contracting when trained to failure?
Myofibril failure; Intermediate failure; Mitochondrial failure
What is myofibril failure?
When resistance is so great the contractile components fail, energy stores rapidly deplete and nervous input is no longer effective.
Which type of failure will cause the most damage and growth?
myofibril failure
What is the best rep range for myofibril failure?
4-6
Soft and hard tissue damage is possible if you typically ________ at the end of extremely heavy pushing movements.
lock out joints
What is intermediate failure?
When contractile components are failing about the same time as short term energy stores are depleted.
What can happen if you perform sets between 7-11 reps for failure, recruiting both red fast and white fast twitch fibers?
Neither type of motor unit will be stressed optimally because they’re sharing the work.
What does Intermediate failure do in a positive way?
results in adaptation through the building of new myofibrils and mitochondria (especially in the red, fast twitch)
What is the preferred rep range for intermediate failure?
12-15
What is mitochondrial failure?
When there is a depletion of energy stores and excessive accumulation of lactic acid
What is the positive result of mitochondrial failure?
adaptation through the increased storage of energy, and the building of new mitochondria, especially in red, slow twitch
What is the optimum rep range for mitochondrial failure?
20-25
What happens if you reach failure in the 16-19 rep range?
It will involve both red, fast and red, slow twitch—not providing optimal involvement of either.
Why is resistance training important for fat loss?
Muscle burns fat; it changes your body’s needs and combats loss of muscle mass along with the fat.
During recovery while on a negative calorie intake, what is broken down and used for energy and what is used by the muscle to fill stores back up again.
Triglycerides (extramuscular fat) is broken down for energy; part of the fat (glycerol) is used to restore the muscle’s energy stores
What is drawn from to provide fatty acid and glycerol to replete exhausted muscle stores on a proper diet?
adipose issues (fat)
What type of resistance exercise (for beginner, fat loss clients) should be performed?
high rep, low intensity, long duration and frequent using basic compound movements
How can you stimulate somewhat of an aerobic effect through resistance training?
decrease recovery between sets;
increase number of sets;
use compound exercises to maximize tissue involvement;
decrease amount of resistance while increasing repetitions
What is muscle energy production in the absence of oxygen?
anaerobic
What is energy production in the presence of oxygen?
aerobic
What is another name for the symptoms of overexertion or injury?
contraindications
What do you get when there are greater and greater fat loss with gains in muscle tissue?
increase in lean weight;
increase in total body weight;
decrease in fat mass
