Principles of Muscular Strength and Endurance

Terminology

Muscular endurance

The ability of a muscle to repeatedly generate a submaximal force or to sustain over time

Strength

The maximal force that a muscle can generate for a single maximal effort

Is typically measured by a 1RM

Hypertrophy

An increase in muscle mass

Atrophy

Loss of muscle mass

Three Types of Muscle Tissue

Smooth

Hollow organs of the body

Stomach, blood vessels

Cardiac

Found only in the heart

Skeletal

Allows for movement

Benefits of Resistive Training

Improved appearance

Increased strength and endurance

Hypertrophy (increase in lean muscle mass)

Increased flexibility (ROM)

Appropriate body composition

Increased performance in daily living activities and potentially sport and game skills

Increased metabolic rate

Basal Metabolic Rate (BMR)

Basically, the number of calories required to sustain life in the resting state

As lean body mass increases, BMR increases

Each pound of muscle tissue raises BMR by 30 to 50 calories every 24 hours

Each pound of fat burns 2 calories every 24 hours

Resistance Training And Osteoporosis

Prevention of osteoporosis

Weight bearing activity

Sufficient calcium

Appropriate estrogen levels

Types of Skeletal Muscular Contraction

Isometric

Isotonic (includes isokinetics)

Concentric contractions (positive)

Eccentric contractions (negative)

Isometric Contractions

Contractions that involve no change in length of the muscle (a static contraction)

Involves no skeletal movement

Involves no joint movement

The resistance force is greater than the contracting force of the muscle.

Example: Pushing outward on the frame of a door.

Isotonic Contractions

Dynamic in nature and involve a muscle length change

May be either Concentric or Eccentric

Concentric Contraction

The muscle shortens during contraction

Eccentric Contraction

The muscle lengthens during contraction

Factors Effecting Muscular Strength and Endurance Training

Muscle Size

Gender

Age

Muscle Size

The strength that a skeletal muscle can produce is related to the cross sectional area of that particular muscle.

Increases in strength results from an increase in the size and number of myofilaments (actin and myosin)

“Use it or loss it”

Gender

Women will experience less hypertrophy as a result of lower testosterone levels

Women need not be concerned with appearing like a female “body builder”

Males, present greater strength, only if they have greater muscle mass.

Age

A loss of skeletal muscle tissue is associated with aging but primarily due to sedentary lifestyle

Loss is somewhat preventable and/or reversible

Muscle Soreness

Results from structural damage of the muscle tissue or connective tissues.

It is desirable to have small, microscopic tears in muscle tissue

As the muscle repairs or rebuilds itself, the end result is a stronger muscle

Avoiding Muscle Soreness

Eliminate or minimize eccentric training

Eliminate or minimize isometric training

Begin training using low intensities

Include stretching in warm-up and cool down activity

Progress slowly

Principles of Weight Training

Modality

Intensity

Repetitions and Sets

Frequency

Split Routines

Total body workouts

Principles of Weight Training

Repetitions & Sets

Precautions

Isometric Training Principles

Isotonic Training Principles

Repetitions and Sets

One set is made up of a number of repetitions

Example: One set of 10 repetitions

Precaution!

NEVER hold your breath while exerting force when weight lifting

Exhale as you apply force

Inhale as you recover

Isometric Training Principles

Increases strength at a given joint angle

Train at a variety of joint angles

Used to be a preferred method of strength training for athletes

Used in rehab settings

Isometric Training Precautions

Individuals should avoid increases in intra-thoracic pressures by not holding their breath during contraction

Valsalva effect or valsalva maneuver

These activites are contraindicated for hypertensive or individuals presenting coronary risk.

Isotonic Training Principles

Constant resistance, variable speed of muscular contraction

Most common method of isotonic training is known as progressive resistance training.

All program variations are based on the Principle of Overload

May use free weights or machines

How Do I Determine The Appropriate Amount Of Resistance For My Workout?

Determine your 1RM

Trial and error

One Repetition Maximum (1RM)

Determine your 1RM

Take 60% of that value and begin with that amount of resistance

60% will develop some strength but mostly endurance

The closer you work to your 1RM, 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, fatiguing on the last repetition

Muscular Strength Training

Requires heavier weights at fewer repetitions

High resistive loads (greater than 60% of 1RM)

3-9 repetitions

Minimum of 3 sets (beginners may need to start with one set, progressing to 2, then 3 sets

Muscular Endurance Training

Requires less weight, higher repetitions

Lower resistive loads (less than 60% of 1RM)

15 or more repetitions (>12 reps, >16 reps)

Minimum of 3 set

Note: Muscular strength gains may accompany gains in muscular endurance.

Practical Guidelines for Isotonic Training

Most popular form of resistive training

Isotonic movements are used in most daily activity

Involves working through a full ROM

Resistive weight remains the same, speed of the contraction or movement is variable

Practical Guidelines Cont.

Warm up

Adjust equipment

Exercise large muscle groups first

Legs or large muscles in the upper body

Begin any resistive training program slowly and with lower intensities.

Follow the tenets of the Principle of Overload and Specificity

Don’t hold your breath while exerting force

Strengthen your weak side by:

Working arms and legs independently

Isolate the muscle group

Work through a full range of motion (ROM)

Protect the back

Practical Guidelines Cont.

Total body workout

Should be done no more than 2 - 3 times per week

May alternate days

May alternate equipment to save time

Maintenance

Two sets, two times per week OR

One set of 12 repetitions

Fatigue on the last rep

Reassess periodically

Equipment Used For Isotonic Training

Free weights

Weight machines

Free Weights

Use a spotter

Increased chance of injury

Lack of stability, although it will develop better balance and muscular control

May build strength faster

Weight increments are easily changed

Weight Machines

Weight increments are usually 5 to 10 to 15 pounds

The machine controls the line of force

Machines offer stability

Fewer injuries

No spotter required

Isokinetic Training Principles

Requires special equipment designed to control and maintain a constant predetermined rate of muscular contraction

Computerized - relies on hydrolics

Characterized by variable resistance and constant speed or velocity of the muscular contraction

Isokinetic Training Principles #2

Disadvantage: COST

Set rate of contraction based on goals and objectives.

Example: Slow contraction speeds produce increases in strength at slow speeds of movement only.

Other Strength Training Techniques

Circuit Training

Plyometrics

Calisthenics

Body Building

Circuit Training

Uses a series of 12 to 15 stations

Rotate through the circuit 3 times

Consists of combinations:

Weight training

Stretching

Calisthenics

Brief aerobic exercise

Plyometrics

Develops muscle explosiveness and forcefulness

Consists of an eccentric contraction followed by a concentric contraction

Involves hops, bounds, depth jumping

High probability of injury

Calisthenics

The body and its extremities provide resistance

Often used in aerobic dance routines

Examples:

Ab crunches

push ups are examples

Best suited as a supplement to strength training rather than as a substitute

Is a good approach for a beginner

Body Building

BB training routines call for back-to-back exercises using the same muscle groups.

BB PUMPS extra blood into muscles causing an APPEARANCE of larger muscles

This condition can last for several HOURS after training UNLESS....

Taking Strength Development A Step Too Far

Anabolic Steroids and Human Growth Hormones

Anabolic Steroids

Synthetic forms of the male hormone, testosterone

Using Anabolic Steroids: Abnormal Hypertrophy

Hypertrophy is based on:

drug type and amount

duration of drug usage

amount of weight training

Females Using Anabolic Steroids Will Potentially Develop:

Hypertension

Fluid retention

Decreased breast size

Facial and body hair

Deeper voice

Harmful Side Effects Found In Men

Liver dysfunction

Reduced testicular function and loss of sexual interest

Headaches, nausea, and acne

Unpredictable aggressive behavior

Increased risk of coronary heart disease (CHD,CAD,CVD)

Increased risk of kidney tumors

Where Can I Get Steroids?

Easily obtained

Mail order

Illegal channels

Local gyms

Athletes

Unfortunately, sometimes physicians

Types of Muscle Fibers

Fast twitch

Slow twitch

Type I Or Slow Twitch

Appear red under the microscope; Red fibers

Are always called into use first

Associated with aerobic activity

Adapted to sustained contractions; Are resistant to fatigue

Smaller than fast twitch

Endurance athletes (long distance runners) have more slow twitch fibers

Type II or Fast Twitch

Appear white under a microscope

Associated with anaerobic activity

Produce fast, powerful contractions; Fatigue easily

Used for Explosive activity

Successful sprinters have a greater percentage of fast twitch fibers

Strength training is associated with anaerobic activity

Type IIB fibers (classic anaerobic fibers)

Type IIA fibers are a mix of characteristics found in Type I and II

Are fast twitch but also are oxygen using

What Determines Fiber Type

Primarily genetics

Given types of training will not develop more fast or slow twitch fibers

Designing An Exercise Prescription For The Development Of Muscular Strength and Endurance

lst step = assess strength

2nd step = determine MODALITY

3nd step = establish routine

Specificity of Training

Training program must be SPECIFIC to obtain desired results

Variables to a Strength Training Program

Mode of Training

Resistance Training

Sets

Frequency of Training

EXERCISES WITHOUT WEIGHTS

Push-ups

Abdominal crunch; curl-up

Dips

Pull-ups

EXERCISES WITH WEIGHTS

Bench Press

Leg Press

Seated Rowing

Arm Curl

Leg Curl

Lat Pull-down

Shoulder Press

Incline Press

Pec Deck

Tricep Press

Back Extension

Total Hip