Download Muscle Strength and Endurance

Muscle Strength and
Endurance
ATHT 333
Ch 7
Strength
 Maximum force a muscle of muscle group
can exert
 Measured in 1 repetition max (1RM)
 Too demanding for injured, so use 10RM
Power
 Strength applied over a distance for a
specific amount of time
 P= F x d/T
Endurance
 Ability of muscle/muscle group to perform
repeated contractions against a less-thanmaximal load
 Ability to do this depends on energy system
available and quantity of forces resisted
Relationship of Strength and
Endurance
 High intensity, low reps = ?
 Strength
– 3-9 reps of 90% 1RM
 Endurance
– 20 reps of 70% 1RM
 6-12 reps at 70-90% 1RM gives us
– Gains in both, but not as good as when
individual
 Training volume- number of sets, reps,
amount of resistance
– One study says 3 sets to increase strength
– ACSM lit review says 1 set of 8-12 reps (or to
fatigue) for strength
 Recovery
– 4 mins for isokinetic, within 1st minute for
isotonic & isometric, then followed by slower
recovery
– Initial rapid recovery due to removal of lactic
acid, slower due to muscles’ metabolic reserves
being depleted
 You are treating a lacrosse athlete with a
quad strain. She performs leg press until
fatigue. How long is her recovery period?
– 30 sec-1min
How many reps?
 Depends…
– Pain tolerance
– Phase of healing
– Demands of sport
 How would a d-lineman, soccer, and
basketball athlete differ?
Length-Tension
 Strength production = active+passive elements
– Active- motor unit
– Passive- connective tissue surrounding
 *A muscles ability to shorten actively lessens as
the length of the muscle diminishes*
– At shortest length, cross bridges of actin & myosin used
– If lengthened before shortened, passive elements are
taut and produce additional resistive force
– Best position, slightly beyond resting length
Muscle cross section size
 Direct correlation b/t cross section size and
strength
– Width of the muscle taken at an angle
perpendicular to the length of fiber
 Cross section greater when fibers are
arranged at angles to the axis of the muscle
– Pennate arrangement
– Example: gastroc
 Angle of pennation
– Varies from one person to another
– One study believes if 2 people have same size
muscle, angle of pennation may be a factor in
differences between strength and speed
Static vs dynamic
 Static = isometric
– Can’t hold for long periods of time at max
tension
 By 5 sec, tension is 75% of that at the start
 Recommended is 6 seconds
 Dynamic = isotonic, isokinetic
– Eccentric can produce 20-40% more force than
concentric
DOMS
 Due to damage of muscle membranes and
secondary inflammatory reaction
 Avoid it
– Don’t use eccentric early in program
– Start at lower intensity
Open Kinetic Chain, Closed Kinetic
Chair
 OKC- distal segment moving freely in space
– Kicking & throwing
 CKC- distal segment fixed, WB, and body
moves over hand/foot
– Running
– Safer in early program due to less shear forces
 CKC improves
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Strength
Power
Stability
Balance
Coordination
Agility
 Lower CKC
– Functional
 Co-activation of
opposing muscle
groups
– Jt stability
 OKC
– In ADL
– Kicking, throwing
– Part of walking
 Proximal muscle
activity initiates
movement
With a partner
 2 OKC and 2 CKC for leg and for arms
Strength Equipment
 Manual resistance
– Technique
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Explain what you’re doing, how many, put Pt. through ROM
Apply resistance so Pt. can move smoothly
Force application near joint, unless you aren’t stong enough
Watch for substitution
– Advantage- hands on is good, immediate feedback
– Disadvantage- time consuming, no objective measure
Body weight
 Progression- increase amount of bw used,
prolong time, increase sets or reps
 Start slow and controlled- move to functional
speed
 Advantage- can be done anywhere
 Disadvantage- if done independently, may
not be doing correctly
Bands and Tubing
 Resistance depends on color
– From light to heavy
 Tan, yellow, red, green, blue, black, grey, gold
 Chose based on MMT results
 Technique- one plane or functional
 Advantage- easy to transport, colors make
progression easy, mimic functional
movement
 Disadvantage- stretching of band creates
more resistance at weaker point in motion
Free weights
 Cuff weight, barbell, dumbbell
 Technique
– Light weight and instruction to begin
– Should be able to control weight
– How is it different from a machine weight?
 Advantage- can be used in various positions
to provide max resistance, qualitative
 Disadvantages- safety, boring
Isotonic machines
 Techniques
– Demonstrate then observe
– Watch speed and muscle substitution
 Advantage- safety, no need for assistance
 Disadvantage- boring, expensive, only in 1
plane of motion
 https://www.youtube.com/watch?v=in1hwXyt
pfM
Isokinetic Machines
 Patient resists machine at max effort
 Techniques
– Preset speed, instruct proper use
 Advantage- Max resistance through ROM,
diagonal patterns can be performed,
measureable results
 Disadvantage- $$$, set up complicated and
time consuming
SNAP
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Specific exercises
No pain
Attainable goals
Progressive overload
Specific Exercises
 SAID principle (specific adaptations to
imposed demands)
– Muscle will adapt according to demands placed
on it
– Should mimic stress placed on muscle during
activity
No pain
 Post exercise pain and edema means
exercises were too severe
 Pain produces a reflex withdrawal of muscle
activity so won’t produce max output
Attainable Goals & Progressive
Overload
 A-Should be possible
– Correct weight for amount of reps desired
 P- Overload Principle
– As a muscles strength adapts to resistance, the
muscle must be additionally overloaded
Resistance Training Programs
 Single set: one set of 8-12
reps of a particular exercise
performed at slow speed
 Tri-sets: group of 3
exercises for same muscle
group performed using 2-4
sets of each exercise with
no rest
 Supersets: either one set of
8-10 reps of several
exercises for same muscle
group done one after
another, or several sets of 810 reps of 2 exercises for
same muscle group with no
rest
 Pyramids: one set of 8-12
reps with light weight, then
increase resistance over 4-6
sets until only 1-2 reps can
be done. Can go from heavy
to light weight.
 Split routine: exercise
different muscle groups on
successive days (MWF
upper body, TThSa lower)
 Circuit Training: exercise
stations with weight training,
flexibility, calisthenics, or
brief aerobic exercises . 812 stations repeated 3
times.
Techniques
 Delorme- based on 10
rep max. The amount
of weight used can be
lifted exactly 10 times.
 Set 1: 50% of 10RM
 Set 2: 75% of 10RM
 Set 3: 100% of 10RM
 Oxford- Reverse of
Delorme
Techniques
 Daily Adjusted Progressive Resistive
Exercise (DAPRE)
–Allows individual differences in the rates at which
patients progress
Techniques
 Berger’s Adjustment
–Should get 6-8RM out of each set with 60-90 sec
recovery between
–If < 6RM, weight too heavy
–If > 8RM, weight too light
–Increase 10% of current rate