Muscular Strength and Endurance/Flexibility

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Muscular Strength and Endurance/Flexibility

• Chapter 4 5

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Muscular Strength and Endurance

• Muscular Strength The maximal force that a
  muscle can generate for a single maximum effort.
  It is usually assessed by measuring strength
  using a one-repetition maximum (1-RM) procedure
  with either free weights or some form of variable
  resistance weight machine.
• Muscular Endurance The ability of the muscle to
  exert a submaximal force repeatedly or
  continuously over time. Usually measured by
  determining the maximum number of repetitions
  that can be performed. (push-ups/curl-ups)

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Basic Skeletal Muscle Characteristics

• Musculo-tendinious unit consists of muscle
  belly and tendons. When a muscle contracts
  (shortens), it moves a bone by pulling on the
  tendon that attaches the muscle to the bone.
• Muscles consist of individual muscle cells or
  muscle fibers. They are connected in bundles. A
  single muscle is made up of many bundles of
  muscle fibers covered by layers of connective
  tissue that hold the fibers together.
• The muscle fibers are made up of smaller units
  called myofibrils. When the brain signals the
  muscle to contract, protein filaments within the
  myofibrils slide across one another causing the
  muscle fiber to shorten. (actin and myosin -
  Sliding Filament Theory)

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Muscle Unit
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Types of Muscle Fibers

• Muscle fibers vary in their structural and
  functional characteristics. Color of muscle
  fiber is one difference.
• CHICKEN vs DUCK

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Types of Fibers

• Slow Twitch (Red) Type I High capacity for
  aerobic energy supply. Very efficient in
  producing ATP. Fatigue resistant. Speed of
  contraction of slow twitch fibers is much slower
  than fast-twitch. They are adapted for low
  intensity, long duration activities. They
  utilize aerobic energy system for fuel.
• Fast Twitch (White) Type II High capacity for
  rapid force development. Rely on anaerobic
  metabolism for fuel. They are explosive and
  powerful, but fatigue quickly.

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Muscles

• Weight training causes the SIZE of the individual
  muscle fibers to increase by increasing the
  number of myofibrils.
• HYPERTROPHY the development of large muscle
  fibers.
• Most muscles contain a mixture of slow and fast
  twitch fibers.
• Inactivity reverses the process
• called ATROPHY.

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Motor Units

• To exert force, the body will recruit one or more
  motor units (nerves connected to fibers) to
  contract. There can be anywhere from 2 to 100s
  of fibers in each unit. The number of motor
  units recruited depends on the amount of strength
  required.
• Small weight ? Few motor units
• Large weight ? More motor units
• Strength training improves the bodys ability to
  recruit
• motor units. (Muscle Learning), thus increasing
• strength even before muscle size increases.

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Motor Units

• Motor units (nerves connected to muscle fibers)
  are recruited to exert force

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BENEFITS OF RESISTIVE TRAINING

• Increased muscular strength, endurance
• Increased muscle size (hypertrophy)
• Increased flexibility or range of motion
• Decreased body fat
• Increased lean body mass
• Increased metabolism
• Improved physical appearance
• Increased performance in activities
• Assists in prevention of osteoporosis

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Assessing Muscular Strength and Endurance

• Muscular strength assessed by determining
  repetition maximum (1 RM), the maximum resistance
  that can be lifted once
• Muscular endurance assessed by counting the
  maximum number of repetitions of a muscular
  contraction

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Training Principles

• Overload A gradual increase in the frequency,
  duration, or intensity of the activity must occur
  is any physiological adaptation is going to
  occur. For resistive training, this principle
  specifically suggests that for greater gains in
  strength, endurance or power to occur there must
  be a manipulation of these factors.
• For endurance, increase the number of repetitions
  in a set, reduce the recovery time between sets
  or a combination of the two.
• For strength, increase the resistance or load,
  while restricting the number of repetitions in a
  set to 10 or lower.
• In each case, over time the muscle will adapt to
  the changes and alter its structure and/or
  function, leading to greater gains.

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Training Principles

• Specificity The human body adapts to how it is
  being trained. The systems of the body will
  physiologically adapt, specifically to the type
  and nature of exercise training. How the body
  adapts, and how much it improves, is directly
  related to how hard, and in what manner, it is
  trained.
• Example If you want a stronger upper body, you
  must train the chest, back, shoulders, and arms.
• If you want bigger quadriceps, you must train
  them!
• If you want to increase muscular strength, you
  need to follow the guidelines for strength
  development more weight, less reps. For
  endurance, less weight, more reps.

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Training Principles

• Reversibility Periods of interrupted training
  will cause, in time, a reduction in
  strength/endurance. Muscle tissue will not
  retain, for any length of time, any gains in
  strength or endurance associated with resistive
  training if training is discontinued or
  drastically reduced.
• Atrophy A reduction of muscle size. This is a
  result of reduced cross sectional area of
  individual muscle cells (size), from lack of
  training or a decrease in the number of cells,
  which is more associated with aging.
• Rate of atrophy due to detraining is
  approximately 1 per week, dependent on the
  nature and extent of detraining. For example,
  total bed rest could be more damaging than just
  quitting your resistive training program.

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Types of Muscular Contractions

• Isometric (Static) Contractions that generate
  muscle tension, but no change in the length of
  the muscle or movement of a joint.
• Example tighten the abdominal muscles while
  sitting still.
• Isometric exercises develop strength only at or
  near the joint angle where they are performed,
  not through the entire joint ROM.
• Used to strengthen muscles after injury or
  surgery when movement of a joint could delay
  healing.
• For maximum gains hold the isometric contraction
  for 6 seconds and repeat 5-10 times.

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Types of Muscular Contractions

• Isotonic (Dynamic) Involves applying force with
  movement. Muscle contractions occur while
  muscles change length.
• Most popular type of exercises for increasing
  strength.
• Can be performed with free weights, machines, or
  your own body weight.
• Concentric Contractions that occur when a
  muscle shortens a positive contraction.
• Eccentric Contractions that occur when a muscle
  lengthens a negative contraction.

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Factors Affecting MSE Training

• Muscle size
• Strength training does not increase the strength
  of contraction of the muscle cells, but rather
  increases in strength result from a proportional
  increase in the diameter or size of the muscle
  cell.
• Gender
• Women will not experience as much hypertrophy as
  men will. This is due to lower levels of
  testosterone.
• Age
• Loss of skeletal muscle tissue is associated with
  aging, however the greatest losses are related
  more to physical inactivity and sedentary
  lifestyle and may be preventable and/or
  reversible.

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FITT PRINCIPLES

• Frequency Training with weights should be 2-3
  nonconsecutive days/week. Muscles require a
  24-48 hour rest between workouts.
• Intensity The amount of weight (resistance)
  lifted. This determines how your body will adapt
  to weight training and how quickly changes will
  occur.
• For strength, may use 80 of 1RM for 1-8
  repetitions.
• Higher amount of weight ? Less Repetitions
• For endurance, use 40-60 of 1RM for 15-20
  repetitions.
• Lower amount of weight ? More Repetitions
• For general fitness, use 70 of 1 RM for
  8-12 repetitions.

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FITT Principle for Strength Training
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FITT PRINCIPLES

• Time of Exercise (Repetitions and Sets)- to
  improve fitness, you must do enough repetitions
  of each exercise to FATIGUE your muscles. The
  number of repetitions needed to cause fatigue
  depends on the amount of weight lifted.
• For a general fitness program for both strength
  and endurance, complete 8-12 repetitions of 8-10
  different exercises, balancing the muscle groups.
  (Ab and calf exercises may require more
  repetitions.)
• Set Refers to the number of repetitions of an
  exercise. Start with 1-2 sets, and build up to
  increase strength. Allow enough rest time
  between sets for the muscles to work at a high
  enough intensity. Can work a different muscle
  group during the rest period to save time.

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• Type or Mode of Exercise For overall fitness
  include exercises for your neck, upper back,
  shoulders, arms, chest, abdomen, lower back,
  thighs, buttocks, and calves about 8-10
  exercises in all.
• Balance between agonist (the muscle contracting)
  and antagonist (the opposing muscle which must
  relax and stretch) muscle groups.
• Example If you do leg extensions (quadriceps),
  also do leg curls (hamstrings).
• Work the large muscle groups or multiple joints
  before working small muscle groups. Example A
  chest press (chest, arms) should be performed
  before a lateral raise (deltoids).
• See back of chapter for exercises.

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Systems of Training

• SET SYSTEM Most popular type of training.
  Person does an exercise for a given number of
  repetitions, or a set, then rests before
  performing another set.
• SUPERSETS An exercise set for a particular
  muscle group is followed by an exercise for the
  opposing muscle group. (biceps/triceps)
• SUPER MULTIPLE SET Same concept as supersets,
  but the lifter completes all of the sets for a
  given muscle group, then completes the same
  number of sets for the opposing muscle group.
• SPLIT ROUTINE Requires a great amount of time
  and work. Lifter alternates muscle groups worked
  each day, and works out more days/week.
• Example M, W, F work arms, legs and abs T,
  Th, Sa, work chest, shoulders and back.

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Systems of Training

• PYRAMID SYSTEM Adding weight until the lifter
  can complete only one repetition.
• Example Bench press with a set of 10 reps, then
  add weight, complete 8-9 reps, add weight,
  complete 6-7 reps continuing until the final set
  is 1 repetition. (Light to Heavy) Can also
  pyramid down from heavy to light weights,
  increasing the repetitions as weight is removed.
• NEGATIVES Emphasis is placed on the eccentric
  part of the exercise. Slower repetitions are
  suggested. (Muscle soreness is usually a
  result.)
• SUPER SLOW Both concentric and eccentric
  movements are slowed down to achieve maximum
  contractions.

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• To start Choose a weight with which you can do
  812 repetitions with good form
• To progress, use the two-for-two rule If your
  goal is 8-12 repetitions, add resistance when you
  do more than 14 repetitions at your previous two
  workouts
• Maintain good form at all times
• Track your progress

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Safety Considerations

• 1. WARM up prior to the workout.
• 2. Breathe properly. Breathe out with strenuous
  position, and in with less strenuous position.
  DONT HOLD BREATH.
• 3. Use spotters with free weights in any
  exercise where you could lose control of the
  weight.
• 4. Always use lock-collars on bar ends so plates
  dont fall off.
• 5. Use proper lifting techniques

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• Machines
• Safe
• Convenient
• Easy to Use
• Dont need spotter
• Rapid, effortless change of resistance
• Controlled range of motion
• Provide both positive and negative
  resistance
• Expensive
• Require a lot of space

• Free Weights
• Requires more balance, coordination
• Allow for a free range of motion
• Versatile
• Provide positive and negative resistance
• Require a number of muscle groups to work
  together when lifting
• May require a spotter
• Require time and effort to adjust resistance.

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Muscular System
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Muscular System
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A Caution About Supplements and Drugs
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A Caution About Supplements and Drugs

• Supplements taken to increase muscle growth
• Anabolic steroids
• Human chorionic gonadotrophin (HCG)
• Growth hormone
• Dehydroepiandrosterone (DHEA) and androstenedione
• Insulin and insulin-like growth factor (IGF-1)
• Beta-agonists
• Protein, amino acid, and polypeptide supplements
  and so-called metabolic optimizing meals

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Side Effects of Anabolic Steroids

• Liver damage and tumors
• Reduced HDL
• High blood pressure, heart disease, cancer
• Depressed immune function
• Psychological disturbances
• Depressed sperm and testosterone production
  breast development in males
• Masculinization in women and children
• Premature closure of bone growth centers

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A Caution About Supplements and Drugs

• Supplements taken to speed recovery from training
• Creatine monohydrate
• Chromium picolinate
• Substances taken to increase training intensity
  and overcome fatigue
• Amphetamines
• Caffeine

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A Caution About Supplements and Drugs

• Substances taken to increase endurance
• Erythropoietin
• Darbepoetien
• Substances taken to aid weight control
• Diethylpropion, phentermine
• Caffeine, PPA, ephedra
• Dinitrophenol
• Diuretics

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Evaluating Dietary Supplements

• Do you need a supplement at all?
• Is the product safe and effective?
• What studies have been done?
• What has the research shown?
• Can you be sure that the specific product is of
  high quality?

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FLEXIBILITY AND LOW BACK HEALTH

• Chapter 5

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FLEXIBILITY

• Flexibility Defined as the range of motion
  (ROM) of a single joint or a group of joints. It
  is specific to each joint. The amount of
  movement is largely determined by the tightness
  of muscles, tendons, and ligaments that are
  attached to the joint.
• Benefits
• Reduce muscle soreness
• Reduce muscle tension
• Reduce risk of low back pain
• Improve muscle performance
• Improve posture
• Improve muscle coordination
• Reduce the risk of injury

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Types of Flexibility

• Active (Dynamic) Flexibility The degree to
  which the force of a muscle contraction can move
  a joint. A muscle is stretched by a contraction
  of the opposing muscle. Involves movement.
  Dynamic shoulder flexibility would affect your
  ability to swing a golf club. Important for
  daily activities and sports.
• Passive (Static) Flexibility Refers to the
  ability to assume and maintain an extended
  position at one end or point in a joints range
  of motion. It involves no muscle contraction.
  An outside force or resistance provided by
  yourself, a partner, gravity or a weight helps
  the joints move through their ROM. Easier to
  measure than dynamic flexibility and is usually
  how we refer to flexibility.

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What Determines Flexibility?

• Joint structurejoints vary in direction and
  range of movement
• Joint capsules semielastic structures that give
  joints strength and stability but limit movement
• Muscle elasticity and length
• Collagen white fibers that provide structure
  and support
• Elastin yellow fibers that are elastic and
  flexible
• Titin muscle filament with elastic properties

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Muscle Elasticity and Length
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Factors That Affect Flexibility

• Joint Structure and related connective tissue
  One cannot change the joint structure and the
  range of motion of each joint will vary. But,
  the length of the resting muscle fibers can be
  developed.
• Soft Tissue Muscle tissue, connective tissue,
  skin, scar tissue, fat tissue can all affect
  flexibility.
• Age Aging decreases the natural elasticity of
  the muscles, tendons and joints resulting in
  stiffness. Sedentary lifestyles, common with
  aging, also affect flexibility.
• Gender The differences tend to be joint
  specific and do not always favor women, which is
  a common perception.
• Muscle temperature Warmed muscles stretch
  better than cold muscles and are less prone to
  injury.
• Pregnancy Due to release of relaxin, there is a
  change in the elastic properties which improves
  muscle and joint flexibility.

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FITT PRINCIPLES

• FREQUENCY minimum of 2-3 days/week 5-7
  days/week may be better.
• INTENSITY Slowly stretch warm muscles to the
  point of slight tension or mild discomfort.
• TIME Hold the stretch for 10-30 seconds
  repeating 3- 5 times. Relax and breath.
• TYPE Stretch the major muscle groups exercised.
  Refer to the end of the chapter for exercises.

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Proprioceptive Neuromuscular Facilitation (PNF)

• Most popular PNF stretching is the contract-relax
  stretching method, in which a muscle is
  contracted before it is stretched.
• The muscle being stretched is held in an
  isometric contraction first, then passively
  stretched. This also works when the opposing
  muscle is contacted prior to the passive stretch.
• Example Stretching the hamstring Contract the
  hamstrings, relax the hamstrings, contract the
  quadriceps, stretch the hamstrings.
• PNF is an effective way to increase flexibility.
  Usually requires a partner. PNF protocol should
  include 4 repetitions of each stretch, 3-5
  days/week.

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Static vs Ballistic Stretching

• Static stretching is the preferred method of
  stretching. A stretch is held to the point of
  slight tension or mild discomfort, but not pain.
  This allows for the development and retention of
  muscular flexibility.
• Ballistic (Bouncing) Stretching is the most
  dangerous of the stretching procedures. It may
  lead to muscle soreness or injury.

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Stretching Techniques
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A Flexibility Workout
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The Lower Back

• Low Back Pain has a direct relationship to
  lifestyle and wellness behaviors. Proper
  lifestyle choices can help prevent LBP.
  Sedentary lifestyles contribute to loss of
  muscular strength, endurance, and a limited ROM.
• Low Back Pain is the number one physical
  complaint by individuals ages 25-60 in the U.S.
  Second most common ailment for job absenteeism
  for ages 30-60. It contributes for 25 of days
  lost for the entire work force.
• LBP will affect 60-80 of the American and
  European population at some point.
• 50 billion will be spent each year by government
  and industry for LBP (job absenteeism, disability
  payments, workers compensations, disability
  insurance, medical and legal fees)
• Most pain occurs in the lumbar (lower) and sacral
  region because it bears the majority of your
  weight.

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Low-Back Health

• Function of the spine
• Provides structural support for the body
• Surrounds and protects the spinal cord
• Supports body weight
• Serves as attachment site for muscles, tendons,
  ligaments
• Allows movement of neck and back in all directions

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Skeletal System
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Structure of the Spine

• 7 cervical vertebrae in the neck
• 12 thoracic vertebrae in the upper back
• 5 lumbar vertebrae in the lower back
• 9 vertebrae at the base of the spine fused into
  the sacrum and the coccyx (tailbone)

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Structure of the Spine
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Vertebrae

• Vertebrae consist of a body, an arch, and several
  bony processes
• Intervertebral disks elastic disks located
  between adjoining vertebrae consist of a gel-
  and water-filled nucleus surrounded by fibrous
  rings serve as shock absorbers
• Nerve roots base of pairs of spinal nerves that
  branch off the spinal cord

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Vertebrae and Intervertebral Disk
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Core Muscle Fitness

• Core muscles include those in the abdomen, pelvic
  floor, sides of the trunk, back, buttocks, hip,
  and pelvis
• Core muscles stabilize the spine and help
  transfer force between the upper body and lower
  body
• Lack of core muscle fitness can create an
  unstable spine and stress muscles and joints
• Whole body exercises and exercises using free
  weights or stability balls all build core muscle
  fitness

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Causes of LBP

• The most common cause of LBP
• is physical inactivity!
• Poor posture
• Faulty body mechanics
• Stressful living and working habits
• Weak musculature especially
• the abs
• Poor flexibility in the lower back
• and hamstrings
• Smoking

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Prevention of LBP

• Exercise regularly to strengthen your back and
  abdominal muscles.
• Lose weight, if necessary, to lessen strain on
  your back.
• Avoid smoking (which increases degenerative
  changes in the spine).
• Lift by bending at your knees, rather than the
  waist, using leg muscles to do most of the work.
• Receive objects from others or platforms near to
  your body, and avoid twisting or bending at the
  waist while handling or transferring it.

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• Avoid sitting, standing, or working in any one
  position for too long
• Maintain a correct posture (sit with your
  shoulders back and feet flat on the floor, or on
  a footstool or chair rung. Stand with head and
  chest high, neck straight, stomach and buttocks
  held in, and pelvis forward).
• Use a comfortable, supportive seat while driving.
• Use a firm mattress, and sleep on your side with
  knees drawn up or on your back with a pillow
  under bent knees.
• Try to reduce emotional stress that causes muscle
  tension.
• Be thoroughly warmed-up before engaging in
  vigorous exercise or sports.
• Undergo a gradual progression when attempting to
  improve strength or athletic ability.

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Treatment of Low Back Pain

• Physical Activity Only 1 of all back patients
  need surgery. Most rehabilitation and prevention
  is lifestyle related.
• Maintain a normal weight. Excess abdominal
  weight can lead to lordosis and poor posture.
• Participate in regular aerobic exercise.
• Participate in regular muscular strength and
  endurance activities, especially for the
  abdominal and back regions.
• Incorporate lower back and hamstring flexibility
  exercises. Work all the planes of motion.

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Managing Acute Back Pain

• Sudden back pain usually involves tissue injury
• Symptoms Pain, muscle spasms, stiffness,
  inflammation
• Treatment
• Ice, then heat
• OTC medication (ibuprofen or naproxen)
• Moderate exercise

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Managing Chronic Back Pain

• Considered chronic if lasts longer than 3 months
• Symptoms Stabbing or shooting pain, steady ache
  accompanied by stiffness, pain that is localized
  or that radiates to other parts of the body
• Treatment Many options, including medication,
  exercise, physical therapy, massage, acupuncture,
  education, and surgery

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Tip of the Day

• Results in training occur with consistency and
  effort a lifestyle habit!