Transcript Principles of Muscular Strength and Endurance

Principles of Muscular
Strength and Endurance
Types of Muscles

Skeletal
 Smooth
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
Lines blood vessels,
hollow organs
Cardiac

Found only in the
heart
Muscular Strength
 Strength:
maximal force a muscle can
generate for a single maximal effort
 1-RM (repetition max) measures muscle
strength
 If you want stronger, more powerful
muscles then your goal should be
strength not endurance
Muscular Endurance
 Represents
the ability of a muscle to
generate a sub-maximal force
repeatedly over time
 If this is your goal then endurance
training is what you need
Benefits of Resistive Training

Inc mm strength
 Inc mm endurance
 Hypertrophy
 Inc flex and ROM
 Inc lean body mass
 Dec body fat
 Inc basal
metabolism

Inc performance
 Maintenance of
indep living
 Improved phys
appearance
 Prevention of
osteoporosis
 Inc CR fitness
 Dec BP
Overload

Gradual increase in frequency, duration, and
intensity
 Goal: recruit or stimulate more muscle tissue
 Long-term adaptation: mm hypertrophy
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Increase in mm cell size as a result of increased
protein synthesis (hyperplasia)
The bigger the mm the more force it can
produce
Principle of Specificity
 The
body will only adapt specifically to
the type and nature of exercise training
that are encountered
 How the body adapts and improves is
related to how hard and in what manner
it is trained
 Speed,
contraction type, mm groups
Detraining
 Principle
of reversibility
 MM
tissue will not retain any gains if
training is discontinued or reduced
 Atrophy
 Reduction
in mm size
Types of Contractions
 Isometric
 Concentric
 Eccentric
Isometric Contraction
 No
change in mm length (static
contraction)
 No joint ROM
Concentric Contraction
 Dynamic
shortens
movement in which the mm
Eccentric Contraction
 Dynamic
movement in which the mm
lengthens
 Usually occur after the mm has been in
a shortened state
Skeletal Muscle Actions
 Static
Movement: no joint movement
 Involve
maximal or submaximal mm
contraction
 EX: Quad sets post ACL surgery
 Dynamic
Movement: changes in mm
length and joint movement
 Resistance
training
Types of Skeletal Muscle
Fibers
 Slow
twitch (Type I)
 Fast twitch (Type II)
 Fast-oxidative-glycolytic
 Fast-glycolytic
(Type IIb)
(Type IIa)
Slow Twitch (Type I)
 Low
intensity, long duration
 Aerobic
 High endurance and fatigue resistant
 Running/cycling rely on Type I fibers
 Postural mm are Type I
Fast Twitch (Type IIa and
Type IIb)
 Rapid
forces
 Capable of shortening and developing
tension 3-5 times faster than slow twitch
 Anaerobic, have limited aerobic power
 Fatigue rapidly
 Type IIa fibers have greater anaerobic
capacity than Type I, Type IIb more than
Type IIa
Factors Effecting MM Strength
and Endurance

Muscle size
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Larger the cross section area, the stronger the
muscle
Strength training does not increase the strength of
contraction, but increases the size of the mm cell
Gender: Females low testosterone level
 Age
 Use it or lose it
 Loss of strength 1%/year after 25 yo
Isometric Training
 Increases
strength at a given joint angle
 No joint movement
 Must
 Used
work a variety of joint angles
primarily in rehab
 Precautions: hypertension (valsalva
effect); indiv presenting coronary risk
Isotonic Training

Most common method
of strength training
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“Progressive resistive
exercise”
Overload principle
Constant resistance
Variable speed of mm
contraction
Free weights, machines
Works full ROM
Isokinetic Training

Speed remains
constant; weight
varies
 Used for
rehabilitation
 Equipment very
expensive (Cybex:
$45,000)
Determining Amount of
Resistance
1
RM
 Trial and error
 Delorme (10 RM)
1 Repetition Maximum
 Determine
1 RM
 Take 60% of that value and begin with
that amount of resistance
 60% will develop strength, but mostly
endurance
 The closer you work to your 1 RM, the
greater the strength gains and the risk
of injury
Trial and Error
 Determine
an amount of resistance you
can lift 8 to 12 times
Delorme
 10
RM
 Complete 3 sets
 1st
set: 50% of 10 RM
 2nd set: 75% of 10 RM
 3rd set: 100% of 10 RM
Guidelines for Resistance
Training
 Warm-up
 Adjust
equipment
 Exercise large muscle groups first
 Begin any resistive program slowly and
with lower intensities
 Overload
Guidelines Cont.
 Strengthen
 Work
your weak side
both arms and legs
 Isolate
muscle groups
 Protect the back
 Total body workout
 2-3
times per week
 Alternate days
 Alternate equipment
Guidelines Cont.
 Maintenance
2
sets, twice/week OR
 1 set of 12 reps
 Reassess periodically
Free Weights

Use a spotter
 Inc chance of injury
 Lack of stability
 May build strength
faster
 Wt increments are
easily changed
Weight Machines
 Weight
increments usually 5, 10 lbs
 The machine controls line of force
 Offers stability
 Fewer injuries
 No spotter required
What is your goal?
 To
gain some strength and some
endurance?
 To build primarily strength?
 To build primarily endurance?
 To develop great hypertrophy?
 As you develop strength, you will
develop some endurance and vice
versa
Identify your goal
 Some
strength and some endurance?
 8-12
reps (60% of 1 RM)
 Primarily
 Fewer
than 8 reps (80%-90% of 1 RM)
 Primarily
 More
RM)
strength?
endurance?
than 12-15 reps (60% or less of 1
Hypertrophy?

50 lbs x 20 reps x 3
sets = 3000 lbs

100 lbs x 6 reps x 3
sets = 1800 lbs
Which workout should you use?
Muscle Soreness
 Results
from structural damage
 Desirable to have small, microscopic
tears
 How to avoid mm soreness:
 Stretch,
minimize eccentrics, minimize
isometrics, use low intensities, progress
slowly
Tips
 Never
hold your breath while exerting
force when weight lifting
 Valsalva
 Exhale
effect or maneuver
as you apply force
 Inhale as you recover
Other Strength Training
Techniques
 Circuit
Training
 Plyometrics
 Calisthenics
Circuit Training
 Uses
a series of 12 to 15 stations
 Rotate through circuit 3 times
 Consists of
 Weight
training
 Calisthenics
 Brief aerobic exercise
Plyometrics
 Develops
mm explosiveness and
forcefulness
 Consists of an eccentric contraction
followed by a concentric contraction
 Involves hops, bounds, depth jumping,
medicine ball, etc.
 High probability of injury
Muscle Dysmorphia

Reverse anorexia
 Feeling of being
small or weak
 Males more
common
 Supplements/steroid
use
 Excessive weight
training
Anabolic Steroids
 Synthetic
forms of testosterone
 MM hypertrophy
 Drug
type and amount
 Duration of drug usage
 Amount of wt training
Female Side Effects
 Hypertension
 Fluid
retention
 Decreased breast size
 Facial and body hair
 Deeper voice
Male Side Effects
 Liver
dysfunction
 Reduced testicular function
 Loss of sexual interest
 Headaches, nausea, acne
 Unpredictable aggressive behavior
 Increased risk of coronary heart disease
 Increased risk of kidney tumors
Where can I get them?

Easily obtained
 Mail order
 Illegal channels
 Local gyms
 Athletes
 Physicians

How to mask steroid use? A science of its
own
Calisthenics
 The
body and its extremities provide
resistance
 Used in aerobic dance routines
 EX: crunches and push-ups
 Suited to supplement strength training
 Good for beginners
Bench Press
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1. Lie on a flat bench with
eyes directly under the bar.
2. Keep feet flat on the floor
with hands spaced evenly
slightly wider than shoulder
width.
3. Lift bar off the racks and
slowly lower the bar to the
highest point on chest.
4. Drive the bar upwards and
back over the eyes to arms
length while exhaling.
Leg Press
Push Ups and Crunches