Principles of Muscular Strength and Endurance

Types of Muscles Skeletal Smooth

Lines blood vessels, hollow organs

Cardiac Found only in the

heart

Muscular StrengthStrength: maximal force a muscle can

generate for a single maximal effort1-RM (repetition max) measures muscle

strength If you want stronger, more powerful

muscles then your goal should be strength not endurance

Muscular EnduranceRepresents 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

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 SpecificityThe 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

DetrainingPrinciple of reversibility

MM tissue will not retain any gains if training is discontinued or reduced

Atrophy Reduction in mm size

Types of Contractions IsometricConcentricEccentric

Isometric ContractionNo change in mm length (static

contraction)No joint ROM

Concentric ContractionDynamic movement in which the mm

shortens

Eccentric ContractionDynamic movement in which the mm

lengthensUsually occur after the mm has been in

a shortened state

Skeletal Muscle ActionsStatic Movement: no joint movement

Involve maximal or submaximal mm contraction

EX: Quad sets post ACL surgeryDynamic Movement: changes in mm

length and joint movement Resistance training

Types of Skeletal Muscle FibersSlow twitch (Type I)Fast twitch (Type II)

Fast-oxidative-glycolytic (Type IIa) Fast-glycolytic (Type IIb)

Slow Twitch (Type I)Low intensity, long durationAerobicHigh endurance and fatigue resistantRunning/cycling rely on Type I fibersPostural mm are Type I

Fast Twitch (Type IIa and Type IIb)Rapid forcesCapable of shortening and developing

tension 3-5 times faster than slow twitchAnaerobic, have limited aerobic powerFatigue rapidlyType IIa fibers have greater anaerobic

capacity than Type I, Type IIb more than Type IIa

Factors Effecting MM Strength and Endurance Muscle size

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 angleNo joint movement

Must work a variety of joint anglesUsed primarily in rehabPrecautions: hypertension (valsalva

effect); indiv presenting coronary risk

Isotonic Training Most common method

of strength training “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 Resistance1 RMTrial and errorDelorme (10 RM)

1 Repetition MaximumDetermine 1 RMTake 60% of that value and begin with

that amount of resistance60% will develop strength, but mostly

enduranceThe closer you work to your 1 RM, the

greater the strength gains and the risk of injury

Trial and ErrorDetermine an amount of resistance you

can lift 8 to 12 times

Delorme10 RMComplete 3 sets

1st set: 50% of 10 RM 2nd set: 75% of 10 RM 3rd set: 100% of 10 RM

Guidelines for Resistance TrainingWarm-upAdjust equipmentExercise large muscle groups firstBegin any resistive program slowly and

with lower intensitiesOverload

Guidelines Cont.Strengthen your weak side

Work both arms and legs Isolate muscle groupsProtect the backTotal 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 MachinesWeight increments usually 5, 10 lbsThe machine controls line of forceOffers stabilityFewer injuriesNo 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 goalSome strength and some endurance?

8-12 reps (60% of 1 RM)Primarily strength?

Fewer than 8 reps (80%-90% of 1 RM)Primarily endurance?

More than 12-15 reps (60% or less of 1 RM)

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 SorenessResults from structural damageDesirable to have small, microscopic

tearsHow to avoid mm soreness:

Stretch, minimize eccentrics, minimize isometrics, use low intensities, progress slowly

TipsNever hold your breath while exerting

force when weight lifting Valsalva effect or maneuver

Exhale as you apply force Inhale as you recover

Other Strength Training TechniquesCircuit TrainingPlyometricsCalisthenics

Circuit TrainingUses a series of 12 to 15 stationsRotate through circuit 3 timesConsists of

Weight training Calisthenics Brief aerobic exercise

PlyometricsDevelops mm explosiveness and

forcefulnessConsists 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 SteroidsSynthetic forms of testosteroneMM hypertrophy

Drug type and amount Duration of drug usage Amount of wt training

Female Side EffectsHypertensionFluid retentionDecreased breast sizeFacial and body hairDeeper voice

Male Side EffectsLiver dysfunctionReduced testicular functionLoss of sexual interestHeadaches, nausea, acneUnpredictable 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

CalisthenicsThe body and its extremities provide

resistanceUsed in aerobic dance routinesEX: crunches and push-upsSuited to supplement strength trainingGood for beginners

Bench Press 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