Transcript AIS Chapter 13 Strength and power assessment

AIS Chapter 13
Strength and power assessment
Strength
• Definition: ability of a muscle to produce force
– Maximal strength
– Strength endurance: repeatedly exert submaximal
force
– Rate of force development (RFD)
• Isometric strength, measured by hand-held
dynamometers
• Dynamic strength
– Isokinetic dynamometry: constant angular velocity
– Isoinertial test: constant load, such as 1 RM
Strength
• Speed-strength, also referred as POWER
– Ability to apply force rapidly
– Isoinertial protocols that use loads aimed at targeting
specific aspects of strength and speed-strength
continuum
– Squat jump, countermovement jump, for lower body
– Bench throw, bench pull, for upper body
– Varying in inertial loads
• Strength endurance
– Max number of repetitions in push-ups, chin-ups…
– Time to fatigue in submaximal isometric contraction
Strength, power, and functional
performance
• Test results highly correlated with physical
performance
– Jumping, sprinting
• Also correlated with skill-dominated activities
– Golf club had speed, grinding in sailing
• Weekly strength training important in maintaining
sprint performance across season in team sport
athletes
• Power is usually a more useful discriminator than
strength
– Strength training more effective for weaker persons
– Power training more effective for stronger persons
Test protocols
• Isometric midthigh pull
– https://www.youtube.com/watch?v=kY2EzwrUhCw
– Measure vertical ground reaction force via force
platform
– Highly related to max strength in dynamic lifts,
substitutes to traditional RM testing
• Maximum strength: 1 RM
– Direct or indirect measurement
Protocols for speed strength
• Assessment against a spectrum of loads
– Performance against > 1 inertial condition
– Allows comparison of speed-strength characteristics
against varying inertial loads
– Decide training needs of each athlete, force-velocity
spectrum
Protocols for speed strength
• Equipment: force platform, linear position
transducer
• Squat jump, countermovement jumps
• Bench throw: explosively press barbell from
chest as faraway as possible
– Usually using Smith machine
• Determine optimal load for average and peak
power output
– Important in designing power training program
– Comparing SJ vs CMJ
Use force platform and force
transducer
Interpretation of test results