Transcript Chapter 2 Task-Specific Strength

Task Specific Strength
Chapter 2
How, What and Why?
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How to train
What should be trained
Why training should be performed
What is strength?
How is it achieved?
Task specific strength has carryover
Elements of Strength
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Maximal muscular performance
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Pm, Fm & Vm
Parametric relation between these variables?
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1RM or personal best
Negative relationships
Force/velocity relationship?
http://www.scripps.edu/cb/milligan/projects.html
Figure 2.1 – 1969
Table on page 19
Nonparametric Relations
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Maximum maximorum performance
Only max under favorable conditions
Pmm, Fmm & Vmm
Relation between Pm and Pmm is nonparametric
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Nonparametric are positive
Nonparametric cont…
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Greater Fmm and Vm WHY?
Stronger and faster
Resistance must be sufficient to allow strength
to be manifested
If force is low then strength plays no role
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What sports?
Training should include both
Example on page 21?
Figure 2.2 max force and specific velocity
Defining Strength
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Ability to produce Fmm
Concentric – shortening against force
Eccentric – lengthening with force
Isometric – no change with force
Fmm must be against high force
Extrinsic Determining Factors
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Mechanical feedback – effect of the outside
forces
Force applied causes a change
Types of resistance
Elastic – force is pos related to distance of stretch
 Inertia – F = MA
 Hydrodynamic – viscosity
 Compound resistance – weights and chains or elastic
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Intrinsic Determining Factors
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Rate of force development (RFD) – time for
force to be manifested
Time to peak force Tm
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Time to peak force is 0.3-0.4 s
Figure 2.8
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Explosive strength deficit 50%
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Figure 2.8
Finger snap (force accumulation)
Table on page 27 – compare?
Explosive Strength Deficit
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May increase Fmm
May increase RFD with explosive work
Strength and power are different
S gradient on page 28
Figure 2.7 - 0.3-0.4 s
Figure 2.9
Velocity
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Inverse relationship
AV Hill equation on page 30
Intermediate range is important
Max power is at 1/3
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why? (pg 31)
Shot putters vs. javelin throwers?
No relationship between Fmm and Vmm
Figure 2.10
Figure 2.13 P=w/t or FxV
Eccentrics
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Much greater than concentric
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Why?
Total force velocity curve
Fewer muscle fibers and EMG
DOMS and damage
Figure 2.14
Stretch-Shortening Cycle (SSC)
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Eccentric-concentric couple
Countermovement jump
Elasticity – stretch induced – what formula?
Stiffness
Muscle – variable
 Tendon – constant
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Tension and stiffness are related
Acts like rubber band – Figure 2.15
Neural Mechanisms
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Muscle spindles – stretch
Golgi tendons – force
Neural loop – reflex
Training enhances this effect
Figure 2.19 (read top pg. 39)
Strength Curves
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Strength changes as a function of ROM
Why is this important for lifting?
Overlap?
Length tension curves
Torque=fd (d=moment arm)
Lever changes and force changes
Figure 2.21
Figure 2.22
Levers and Strength
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Strength = force moment arm ratio
Short levers create more force
Line of force action is close to joint when force
is high
Figure 2.26
Summary
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Parametric relations are
negative
Nonparametric may be
positive
Max force equals
strength
External factors such as
type of resistance
Time of force
production
RFD is important
(isometric)
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Strength and power are
different
Concentric vs. eccentric
strength
SSC reactive strength
Elastic and neural
Spindles vs. golgi
Length tension
Lever length
Next Class
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Lab tonight on VJ force, velocity and
jump height (CMJ vs SJ) and
unloaded knee extension velocity (R
vs L)
Homework explanation
Read Huxley article and write synopsis
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Next week Chapter 3 and lab
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