ex phys 1 exam 1 all terms

3 principles of adaptation

overload, specificity, progression

-adaptations to exercise occur only as specific response to specific stress

strength training

repeated overloading of force generation

muscle strength

amount of force that muscles exert against resistance

-short period of time

factors that influence muscle strength

-amount of contractile protein

-fiber size

-fiber type

-gender differences

-biomechanics

-neurological activation

gains in strength (precede/follow) muscle growth

precede

early strength gains (0-4 weeks) are the result of:

neural adaptations

neural adaptations

learning the skill of contraction

-coordination

-better summation: higher frequencies

-better recruitment (more motor units, more appropriate motor units)

hypertrophy

increased size of muscle fibers

-major process of growth via training

hyperplasia

increased number of muscle fibers

-minor contribution to growth via training

-important for repair and regeneration

how do muscles grow

by adding more protein (actin, myosin, troponin, and tropomyosin)

more crossbridges = more force

summary of strength adaptations

Neural adaptations

-improved recruitment of motor units

-higher frequency of stimulation (summation)

-improved coordination

Hypertrophy

-increased muscle protein content

increased muscle protein (increases/decreases) the demand for ATP

increases

where is ATP synthesized

mitochondria

more protein with the same amount of mitochondria (increases/decreases) endurance

decreases

endurance

ability to continue muscle contraction for a long period of time

endurance training

repeated overload of ATP generation (metabolism)

adaptations to endurance training

-increase of type 2A fibers

-increased aerobic enzyme efficiency

-more, bigger mitochondria

-better blood flow (more capillaries)

is endurance training associated with hypertrophy

no

flexibility

-how well a joint can move through its range of motion

-norms for ranges for each joint

-have to have ROM prior to strengthening for maximal potential

-important component of physical fitness (activities of daily living, athletic performance, injury prevention)

controversial effect of stretching on athletic performance

-may improve performance

-may decrease performance

-may protect against injury

-may increase likelihood of injury

best time to stretch relative to working out

best to warm-up first or stretch after a workout

common types of flexibility training

static stretching, dynamic stretching

static stretching

holding a pose for an extended period

dynamic stretching

incorporates movement

definition of power

the speed at which muscle forces are used

equations for power

P = W/t, where W is work and t is time

W = Fd where F is force and d is displacement

P = Fd/t = Fv (v = velocity)

plyometric exercise

-allows muscle to reach maximal force in the shortest time possible

-quick, powerful movement using prestretch or countermovement

tendons can be stretched in a (concentric/eccentric) phase

eccentric

-elastic potential energy stored

what follows tendon stretching

contraction + release of potential energy

what body system detects tendon lengthening

nervous system

response of nervous system to tendon stretching

further activating the muscle

eccentric phase must be (rapid/slow) and quickly followed by ___

rapid, concentric phase

muscle soreness may occur after ___

acute resistance training

muscle soreness is most dramatic in ___

inexperienced or novice weight lifters

why do eccentric exercise trigger soreness

may damage the Z disc

-anchors the contractile protein actin

when does muscle soreness typically occur

24-48 hours after exercise

-may last up to 10 days

symptoms of muscle soreness

-local muscular stiffness

-tenderness

-local edema

-limitations in ROM caused by edema

-pain

2 types of muscle fatigue

central fatigue, peripheral fatigue

central fatigue

reduction in voluntary drive to motor neurons during exercise

peripheral fatigue

loss of force and power that is independent of neural drive

nature and extent of fatigue depend on ___

type, duration, and intensity of exercise

EC coupling step 1

electrical signal arrives at NMJ

EC coupling step 2

ACh released from motor neuron

-ACh enters synaptic cleft and moves across by diffusion

EC coupling step 3

ACh binds to ACh receptors (AChR)

EC coupling step 4

AChR generate new electrical signal in the sarcolemma

EC coupling step 5

Electrical signal travels along the sarcolemma

-spreads in all directions

EC coupling step 6

electrical signal travels down t-tubules

EC coupling step 7

electrical signal activates SR

EC coupling step 8

SR releases calcium ions (Ca2+)

calcium reuptake

-SR constantly pumps Ca2+ out of the cytoplasm back into the SR

-terminates the signal to contract if SR is not continually activated

EC coupling step 9

Ca2+ binds troponin

-the higher the Ca2+ concentration in the cytoplasm, the more troponins will bind Ca2+

EC coupling step 10

troponin changes shape

-this change moves tropomyosin to expose actin to myosin and start the crossbridge cycle

crossbridge cycle step 1 name, activation status, things attached to myosin

-crossbridge formation

-myosin head activated

-myosin bound to actin, ADP and Pi attached to myosin

crossbridge cycle step 2 name, activation status, things attached to myosin

power stroke

-myosin head deactivated

-myosin bound to actin

-nothing attached to myosin (ADP and Pi released)

crossbridge cycle step 3 name, activation status, things attached to myosin

detachment

-myosin head deactivated

-myosin not bound to actin

-ATP attached to myosin

crossbridge cycle step 4 name, activation status, things attached to myosin

activation

-myosin head activated

-myosin not bound to actin

-ADP and Pi attached to myosin

3 types of contraction

isotonic, isometric, isokinetic

isotonic contraction

constant force (length changes)

2 types of isotonic contraction

concentric, eccentric

concentric contraction

shortening

eccentric contraction

lengthening

isometric contraction

constant length

isokinetic contraction

constant velocity (force changes)

isokinetic training

-load is adjusted throughout the movement to overload the muscle at each angle/length

-speed is constant

factors that vary by muscle type

-contraction speed

-metabolic properties (how much O2 used)

-capillary density (O2 delivery)

-number of mitochondria (site of O2 use)

-myoglobin concentration (red or white)

function of myoglobin

helps move O2 to the mitochondria

are all fibers within a motor unit the same type

yes

are all fibers within a muscle the same type

no

3 main types of muscle fibers

1, 2A, 2B

type 1 muscle

slow twitch

type 2A muscle

fast oxidative

type 2B muscle

fast glycolytic

isoforms

proteins that are functionally and structurally similar but with slight differences

1 slow isoform

beta

3 fast isoforms

IIa, IIb, IIx

the isoform determines:

-speed at which myosin proceeds through the cross bridge cycle

-determines maximum force

type 1 muscle fiber properties

-slow-twitch

-oxidative (aerobic)

-high capillary density

-many mitochondria

-high myoglobin (red in color)

-fatiuge-resistant (endurance)

type 2A fiber properties:

-fast twitch

-oxidative and glycolytic (aerobic and anaerobic)

-intermediate capillary density

-many mitochondria

-fatigue-resistant (less so than type 1) and fast (not as fast as type 2B)

type 2B fiber properties:

-fast-twitch (very fast)

-glycolytic (anaerobic)

-low capillary density

-few mitochondria

-very little myoglobin (white in color)

-vulnerable to fatigue

-produce high force in brief spurts

-also known as 2X

type 1 speed

slow

type 2A speed

fast

type 2B speed

very fast

type 1 oxidative capacity

high

type 2A oxidative capacity

high

type 2B oxidative capacity

low

type 1 glycolytic capacity

low

type 2A glycolytic capacity

high

type 2B glycolytic capacity

high

type 1 resistance to fatiuge

high

type 2A resistance to fatigue

intermediate

type 2B resistance to fatigue

low

type 1 mitochondrial density

high

type 2A mitochondrial density

high

type 2B mitochondrial density

low

type 1 capillary density

high

type 2A capillary density

intermediate

type 2B capillary density

low

type 1 myoglobin

high (red)

type 2A myoglobin

intermediate

type 2B myoglobin

low (white)

type 1 activity suited for

aerobic (ex. marathon running)