Transcript Progressive Resistance Exercises

Chapter 4: Preventing
Injuries Through Fitness
Training
Reduce Injury
Prepare the Athlete
Athletic Trainers and Strength
and Conditioning Coaches
• Cooperative relationship that serves to
condition athletes in an effort to minimize
injury and maximize performance
• Knowledge of flexibility, strength, and
cardiorespiratory endurance is necessary
• Many strength coaches are certified through
the National Strength and Conditioning
Association
• Athletic trainer may be called upon to
review programs/make suggestions
– Take into consideration components of
particular sport and injury prevention
• Rehabilitation of injuries is the
responsibility of the athletic trainer
• Different settings (professional, college,
high school) will require differing levels of
supervision by the ATC
Principles of Conditioning and
Training
• Warm-up/Cool-down
• Motivation
• Overload and SAID
principle
• Intensity
• Specificity
• Individuality
• Consistency/routine
• Relaxation/Minimize
Stress
• Progression
• Safety
Warm-up
• Precaution against unnecessary musculoskeletal
injury and soreness
• May enhance certain aspects of performance
• Prepares body physiologically for physical work
• Stimulates cardiorespiratory system, enhancing
circulation and blood flow to muscles
• Increases metabolic processes, core temperature,
and muscle elasticity
General
– Activities which bring a general warming to the
body(break a sweat)
– Not related to sport
Specific
– Specific to sport
– Stretching, jogging, running, throwing,
catching
Should last 10-15 minutes resulting in effects
that will last 45 minutes
Cool-down
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Essential component of workout
Bring body back to resting state
5-10 minutes in duration
Often ignored
Decreased muscle soreness following
training if time used to stretch after workout
Improving and Maintaining
Flexibility
• Ability to move a
joint(s) smoothly
through a full range of
motion (ROM)
• Good flexibility is
essential for successful
physical performance
• Decreased ROM results
in:
– Decreased performance
capabilities
– Uncoordinated/awkward
movements
– Predisposes athlete to
injury
• Recommended by
athletic trainers to
prevent injury
Factors That Limit Flexibility
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Bony structures
Tissue approximation
Excessive fat
Muscle and tendon lengths
Connective tissue
Scarring and contractures
Skin
Neural tissue tightness
Range of Motion
(ROM)
• Active range of
motion
– Dynamic flexibility
– Ability to move a
joint with little
resistance
• Passive range of
motion
– Static flexibility
– Motion of joint to end
points without muscle
contraction
Range of Motion
• Must be able to move through unrestricted
range
• Must have elasticity for additional stretch
encountered during activity
Agonist vs. Antagonist Muscles
• Joints are capable of multiple movements
• Agonist
– Muscle producing movement
– Quadriceps contract to produce knee extension
• Antagonist
– Muscle undergoing stretch during movement
– Hamstrings will stretch during knee extension
• Agonist and antagonist work together to
produce smooth coordinated movements
Stretching Techniques
Ballistic
– Bouncing movement in which repetitive
contractions of agonist work to stretch
antagonist muscle
– Spindles tighten instead of relax
– Possible soreness due to repeated eccentric
contractions of antagonist
– Also referred to as dynamic stretching
– May more closely mimic muscle activity during
sport
Static stretching
– Passively stretching
– 6-8 second hold
– Go to point of pain
and back off and
hold for 30 seconds
(3 to 4 times)
– Controlled, less
chance of injury
– Not dynamic
• Proprioceptive Neuromuscular
Facilitation Techniques
– Used by physical therapists for
neuromuscular paralysis
– Slow-reversal-hold-relax
– Contract-relax
– Hold-relax
– Best technique to improve
flexibility
– Autogenic inhibition (push =
tension)
– Reciprocal inhibition (pull = relax)
• Stretching Neural
Structures
– Must differentiate
between
musculotendinous
tightness and neural
tension
• Stretching Fascia
– Fascia can limit motion
(pain, injury,
inflammation)
– Can be performed
manually or using
foam roller
Neurophysiological Basis of
Stretching
Stretch Reflex
– Muscle is placed on stretch(muscle spindle)
– Muscle spindles fire relaying information to
spinal cord
– Spinal cord relays message to golgi tendon and
increases tension
– After 6 seconds golgi tendon organ (GTO)
relays signal for muscle tension to decrease
– Prevents injury - protective mechanism
• With static stretching golgi tendons are able
to override impulses from muscle spindle
following initial reflex resistance
• Allows muscle to remain stretched without
injury
• Using PNF = benefit greatly from these
principles
– With slow-reversal hold technique, maximal
contraction of muscle stimulates GTO reflex
relaxation before stretch applied
– Relaxation of antagonist during contraction =
autogenic inhibition
• During relaxation phase, antagonist is
placed under stretch but assisted by agonist
contraction to pull further
• Contraction elicits additional relaxation of
antagonist (protect against injury)
• Referred to as reciprocal inhibition
The Pilates Method
• Conditioning program that improves muscle
control, flexibility, coordination, strength
and tone
• Enhances body awareness, improves body
alignment and breathing, increases
movement efficiency
• Designed to stretch and strengthen muscles
through a sequence of carefully performed
movements
• Utilizes specific breathing pattern for each
exercise
• Goal
– Develop a healthy self image through posture,
coordination and flexibility
• Generally begins with one-on-one session in
order to assess client’s physical condition
• Classes in a studio are also available
– Very popular in health clubs and gyms
Yoga
• Based on philosophy that illness is related
to poor mental attitude, posture and diet
• Reduce stress through mental and physical
approaches
• Used to unite mind and body
• Involves various postures and breathing
exercises
– Designed to increase mobility and flexibility
Flexibility vs. Strength
• Co-exist
• Believed that muscle bound = zero flexibility?
• Strength training will provide individual with
ability to develop dynamic flexibility through
full range of motion
• Develop more powerful and coordinated
movements
Measuring Range of Motion
• Various devices have been designed to
accommodate joint sizes and complexities
of movement
• Goniometer most widely used device
– Protractor (degrees) that utilizes alignment of
two arms parallel to longitudinal axis of two
segments involved in motion
• Relatively accurate tool for measurement
Flexibility, Muscular
Strength, Endurance,
and Power
Muscle Strength, Power, and
Endurance
• Strength: ability to generate force against
resistance
• Power: is the relationship between strength
and time
• Muscular endurance: repetitive muscular
contractions (increase strength = increase
endurance
Muscle Contractions
• Isometric contraction
– No length change occurs during contraction
– Pro: quick, effective, cheap, good for rehab
– Con: only works at one point in ROM
• Isotonic contraction
– Concentric- shortening of muscle with contraction in
an effort to overcome more resistance
– Eccentric - lengthening of muscle with contraction
because load is greater than force being produced
– Both are considered dynamic movements
Fast Twitch vs. Slow Twitch
• Fibers within a particular motor unit
display distinct metabolic and contractile
capability
Slow twitch (Type I):
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Fatigue resistant
Time necessary to produce force is greater
Long duration, aerobic type activities
Generally major constituent of postural muscles
Fast twitch (Type II)
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Fatigue
Anaerobic in nature
High force in short amount of time
Produce powerful movements
A vs. B
Individual make-up
– Muscles contain both types of fibers
– Muscle functioning impacts ratios (postural vs.
powerful movement)
– Genetically determined
Metabolic capabilities can change in
response to training
Physiological and Biomechanical
Factors that Determine Levels of
Muscular Strength
• Hypertrophy vs. Atrophy
• Size of muscle: function of diameter and
number of fibers
• Neuromuscular efficiency
• Biomechanical factors
• Overtraining (psychologically,
physiologically)
• Reversibility
Explanation for Muscle
Hypertrophy
• Three theories of muscle hypertrophy:
– Increase in number of fibers
– Infusion of blood - transient hypertrophy
– Increase in protein myofilament number and
size
• PROVEN
• Improved Neuromuscular Efficiency
– Early gains minus hypertrophy
– Enhanced efficiency due to enhanced neural
function
• Other enhancements due to training
– Increased non-contractile tissue strength, bone
mineral content, aerobic/anaerobic enzymes,
enhanced oxygen uptake
Techniques of Resistance
Training
• Progressive resistance exercise
• Overload principle must be applied
• Must work muscle at increasingly higher
intensities to enhance strength over time
• If intensity of training does not increase, but
training continues, muscle strength will be
sustained
Overload Principle
• Activity must be increased and upgraded
constantly in order to gain a higher response
from the body
• Work at or near maximum capacity
• Applicable to conditioning and training
• Isometric Exercises
– Contraction where muscle length remains
unchanged
– Muscle contraction that lasts 10 seconds and
should be perform 5-10 times/daily
– Pro: quick, effective, cheap, good for
rehabilitation
– Con: only works at one point in ROM,
produces spiking of blood pressure due to
Valsalva maneuver
Progressive Resistance Exercises
(Isotonic training)
– Shortening/lengthening
– Concentric vs. Eccentric
– Various types of
equipment can be utilized
• (Free weights, machine
weight)
– Spotter is necessary for
free weight training to
prevent injury, motivate
partner and instruct on
technique
• Concentric and eccentric training should be
incorporated for greatest strength
improvement
• Concentric phase of lift should last 1-2
seconds, eccentric phase 2-4 seconds
• Variations exist between free and machine
weight lifting
– Motion restrictions, levels of muscular control
required, amount of weight that can be lifted
• Terminology associated with weight
training
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Repetitions
Repetition maximum
One repetition maximum
Set
Intensity
Recovery period
Frequency
• When training should be able to perform 3
sets of 6-8 repetitions
• Increases should occur in increments of
10%
• 1 RM can be utilized measure maximum
amount of weight that can be lifted - must
be very careful
• Training of a particular muscle group
should occur 3-4 times per week (not on
successive days)
Muscular Endurance vs.
Strength
• Training for endurance enhances strength
and vice versa
• Training for strength should involve lower
repetitions at heavier weight
• Training for endurance requires lower
weight at 12-15 repetitions
• Persons that possess greater strength also
tend to exhibit greater muscular endurance
Isokinetic Training
• Muscle contraction at a constant velocity
• Maximal and constant resistance throughout
the full range of motion
• Maximal effort = Maximal strength gains
• Disadvantages
– Cost
– Need for maximal effort/motivation
• Rehabilitation
Circuit Training
• Combination of exercise stations
• 8 - 12 stations, 3 times through
• Design for different training goals
– Flexibility
– Calisthenics
– Aerobic exercise
Calisthenic Strengthening
Exercises
• Free exercise
• Isotonic training
• Gravity’s involvement determines level of
intensity
• Full range of motion, may incorporate
holding phase
• Pull-ups, push-ups, back extensions, leg
extensions
Plyometric Exercise
• Rapid stretch, eccentric contraction
followed by a rapid concentric contraction
to create a forceful explosive movement
• Rate of stretch vs. magnitude
• Jumps, bounds, medicine ball throws
• Very technical training - skills must be
learned with appropriate technique
Training for the Female Athlete
• Critical for female athlete
• Significant hypertrophy is related to
testosterone present within body
• Remarkable gains are experienced initially
due to enhanced nervous system and muscle
interaction (efficiency-not muscle bulk)
• Following initial gains, plateau occurs, with
females
• Males tend to continue to increase strength
with training
• Critical difference is the ratio of strength to
body fat
– Females have reduced strength to body weight
ratio due to higher percentage of body fat
– Ratio can be enhanced through weight training
and decrease in body fat percentage/increased
lean weight
Strength Training in
Adolescents
• If properly supervised young athletes can
improve strength, power, endurance,
balance and proprioception
• Develop a positive body image
• Results in improved sports performance
while preventing injuries
• Strength gains can occur without significant
muscle hypertrophy
• Close supervision and instruction is critical
• Progression = based on physical maturity
• Utilize calisthenic exercises and body
weight as resistance
Cardiorespiratory Endurance
• Perform whole body activities for extended
period of time
• Performance vs. fatigue vs. injury
• System’s four components
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Heart
Lungs
Blood vessels
Blood
• Improvements in endurance are the results
of improvements in these 4 components
• Aerobic capacity = VO2max
• Increases in intensity require higher levels
of oxygen consumption
• Inherit certain range of maximum aerobic
capacity
• More active = higher capacity
• Average value = 45-60 ml O2/min/kg
• Three factors impact capacity
– External respiration
– Ventilatory process
– Gas transportation (most limiting factor)
Impact on Heart
• Main pumping mechanism
• Increase exercise = increased oxygen
requirement=increase heart pumping
• Heart must gradually adapt to imposed
demands but will reach steady state after 23 minutes of training
• Heart able to adapt through increases in
heart rate and stroke volume which will
enhance overall cardiac output
• A training effect results with regard to
cardiac output.
• Over the course of training, at a given
intensity, stroke volume increases while
heart rate is reduced
• Cardiac functioning becomes more efficient
(hypertrophy of heart occurs)
Cardiac Output = Increased Stroke Volume x Decreased Heart Rate
Energy Systems
• Various sports entail different energy
demands
• Long distance running and swimming vs.
sprinting and jumping
• ATP: Immediate Energy Source
– ATP produced from glucose breakdown
– Glucose from blood or glycogen (muscle or
liver) broken down to glucose converted to ATP
– Fat becomes utilized when glycogen stores
depleted
• Aerobic versus Anaerobic Metabolism
– Both generate ATP
– Initial ATP production from glucose occurs in
muscle (without oxygen = anaerobic)
– Transition to glucose and fat oxidation
(requiring oxygen = aerobic) to continue
activity
– Generally both systems occur to a degree
simultaneously
– Type of ATP production relative to intensity
• Short burst (high intensity) = anaerobic
• Long duration (sustained intensity) = aerobic
Types of Training for
Cardiorespiratory Endurance
• Level of improvement will be determined
by initial levels
• Continuous
– Mode (type of exercise) - must be aerobic in
nature
– Frequency (at least 3 times/week)
– Duration (at least 20 minutes)
– Intensity (must elevate heart rate to 70% of
maximum)
• Interval training
– Intermittent activities involving periods of
intense work and active recovery
– Must occur at 60-80% of maximal heart rate
– Allows for higher intensity training at short
intervals over an extended period of time
– Most anaerobic sports require short burst which
can be mimicked through interval training
• Fartlek training
– Cross-country running that originated in
Sweden
– Speed play
– Similar to interval training in the fact activity
occurs over a specific period of time but pace
and speed are not specified
– Consists of varied terrain which incorporates
varying degrees of hills
– Dynamic form of training
– Must elevate heart rate to minimal levels to be
effective
– Popular form of training in off-season
• Equipment for Endurance Training
– Cost can vary from $2- $60,000
– Jump rope to treadmill and computers
• Fitness Assessments
– Provides coaching and athletic training
personnel with information relative to fitness
and preparedness
– Pre-testing and post-testing format should be
utilized
– Can assess all facets of training and
conditioning with established tests and
protocols
Periodization in Training and
Conditioning
• Traditional seasons no longer exist for
serious athletes
• Periodization
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Achieve peak performance
Decrease injuries and overtraining
Program that spans various seasons
Modify program relative to athlete’s needs
Macrocycle
• Complete training cycle
• Seasonal approach based on preseason, inseason, and off-season
• Changes in intensity, volume, specificity of
training occur in order to achieve peak
levels of fitness for competition
• Broken into mesocycles (lasting weeks or
months)
Mesocycles
• Transition period:
– Follows last competition (early off-season)
– Unstructured (escape rigors of training)
• Preparatory period:
– Off-season
– Hypertropy/endurance phase (Low intensity
with high volume)
• Allows for development of endurance base
• Lasts several weeks to 2 months
– Strength Phase
– Power Phase (High intensity/ pre-season)
• Preparatory period (continued)
– Strength Phase
• Intensity and volume increase to moderate levels
– Power Phase (High intensity/ pre-season)
• Volume is decreased to allow adequate recovery
• Competition period:
– May last a week or several months for seasonal
sports
– High intensity, low volume, skill training
sessions
– May incorporate microcycles (1-7 days)
• Designed to ensure peak on days of competition
Cross Training
• Training for a sport with substitutions of
alternative activities (carryover value)
• Useful in transition and preparatory periods
• Variety to training regimen
• Should be discontinued prior to preseason
as it is not sport-specific