Transcript EXS 6130-Z, 9

Chapter 9
Principles of Strength Training
and Conditioning
Copyright © 2012 American College of Sports Medicine
• This chapter focuses on the 3 key principles of:
Progressive Overload, Specificity, and Variation.
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Critical Components of Training Program
Design
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Progressive Overload
• Definition
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Gradual increase in stress placed on human body during training
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The human body has no need to become stronger or more
conditioned unless it is forced to meet higher physical demands
• Accommodation
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Staleness resulting from a lack in change in training program
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Progressive Overload (cont’d)
• Ways to Incorporate Progressive Overload into
Resistance Training (RT)
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Resistance/loading may be increased
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Repetitions may be added to current workload
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Lifting velocity with submaximal loads may be increased to increase
neural response once technique is mastered [Because force = mass x
acceleration, increasing rep velocity (while mass remains constant) results in higher
peak force and greater strength enhancement]
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Rest intervals may be lengthened to enable greater loading
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Training volume may be increased within reasonable limits [2%-5%] or
varied to accommodate heavier loads
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Other supramaximal-loading training techniques may be introduced
[forced reps, heavy negatives, etc.]
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Progressive Overload (cont’d)
• Flexibility
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Increase in:
• Intensity
• Volume
• Duration
• Frequency
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Progressive Overload (cont’d)
• Power, Speed, and Agility
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Increase in:
• Intensity
• Volume
• Frequency
• Rest intervals
• CAUTION must be used as volume & intensity are inversely related so
proper recovery in between workouts is mandatory!
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Aerobic Endurance
• Increase in:
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Volume [distance]
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Duration [length]
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Intensity [faster rates, add resistance, uphill]
• Decrease in:
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Rest intervals
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Specificity
• Principle
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All training adaptations are specific to the stimulus applied
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Training adaptations should be specific to:
• Muscle actions involved
• Velocity of movement & rate of force development
• ROM
• Muscle groups trained
• Energy metabolism
• Movement pattern
• Intensity/volume of training
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Specificity (cont’d)
• Transfer of training effect applies to:
–
Strength carryover from:
• Unilateral training (to opposite limb)
• Trained muscle action to nontrained action
• Limited-ROM training to other areas of ROM or full ROM
• One velocity to another
–
Motor performance improvements resulting from RT
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Specificity (cont’d)
• Muscle Actions
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Muscle strength is increased specifically by RT with:
• Eccentric (ECC) actions
• Concentric (CON) actions
• Isometric (ISOM) actions
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Specificity (cont’d)
• Velocity of Movement
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Greatest strength increases take place at or near training
velocity
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Some carryover effects:
• To nontrained velocities
• Between muscle actions
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Moderate velocity produces greatest strength increases
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Greatest carryover effects seen in untrained or moderately
trained individuals
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Specificity (cont’d)
• Range of Motion
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Specificity of ROM is seen during limited-ROM:
• Dynamic training
• Isokinetic training
• ISOM training
• Full ROM is best
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Specificity (cont’d)
• Muscle Groups Trained
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Adaptations occur mainly in muscle groups that were trained
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Adaptations can only take place when muscle group-specific
exercises are performed
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Training all major muscle groups is important for:
• Attaining muscle balance
• Reducing injuries
• Optimizing performance
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Specificity (cont’d)
• Energy Metabolism
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Adaptations to training are specific to energy system
involvement
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Energy systems adapt mostly by increasing:
• Enzyme activity
• Substrate storage/usage
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Interaction between volume, intensity, repetition velocity, &
rest-interval length is critical to eliciting acute metabolic
responses that target different systems
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Specificity (cont’d)
• Movement Patterns
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Free weights vs. machines
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Open- vs. closed-chain kinetic exercises
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Unilateral vs. bilateral training
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Movement-specific training (overweight/underweight
implements)
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• Open- Versus Closed-Chain Exercises
– Open-enables the distal segment to freely move
against loading: leg extension, leg curl
– Closed-distal segments fixed: leg press, squat.
– Many closed-chain are multi-joint while open are
single-joint
– Closed-chain may be better for motor function skill
increase
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Unilateral Versus Bilateral Training
• Uni—one arm or leg
• Bi-two
• Cross education
• Bilateral deficit
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Variation
• Definition
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Alterations in one or more program variables over time to keep
stimulus optimal
• Principles
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Human body adapts rapidly to stress
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Variation is critical for subsequent adaptations to take place
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Systematic variation of volume & intensity is most effective for
long-term progression
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Progression and Program Design
• Training Status and Progression
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Training status reflects:
• Fitness level
• Training experience
• Genetic endowment
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Largest rates of strength improvement occur in untrained people
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Resistance-trained individuals show slower rate of progression
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Rate & magnitude of progression decrease with higher levels of
conditioning
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Plateaus near genetic ceiling [Principle of Diminishing Returns]
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Progression and Program Design (cont’d)
• General-to-Specific Model of Progression
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Untrained people
• Less-specific training is sufficient
• No need for complexity
• Training characterized by:
• Learning proper technique
• Building conditioning base
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Advanced training targeting progression is more complex &
requires great variation specific to training goals
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General-to-Specific Model of Training and
Progression
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Individualization
• All individuals respond differently to training
• Factors involved in individual level of adaptation:
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Genetics
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Training status
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Nutritional intake
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Program
• The most effective programs are those designed to meet
individual needs
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Individual Responses to Training
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Detraining (Principle of Reversibility)
• Definition
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Complete cessation of training or substantial reduction in:
• Frequency
• Volume
• Intensity
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Results in:
• Performance reductions
• Loss of beneficial adaptations associated with training
• In RT, may lose more power than strength
• May occur in as little as 2 weeks after cessation
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Importance of Supervision
• Supervision
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Fewer injuries & better technique
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Enhanced performance
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Higher rate of progression
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Greater intensities self-selected
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The Effects of a Personal Trainer on SelfSelected RT Intensities in Healthy Women
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