Transcript Muscular Strength and Flexibity

Muscular Strength and Flexibility
• Body has more than 600 muscles
• Disuse vs. Use
• Atrophy vs. Hypertrophy
Benefits of Resistance Training
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Fat loss and weight control
Improved personal appearance
Get stronger and reduce risk of injury
Strong, healthy bones
Stay healthy
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Increases muscle mass/decreases fat
Increases muscle strength and endurance
Increases metabolic rate
Increases bone density
Improves balance
Improves mobility and range of motion
Improves reaction time
Health Benefits of Resistance Training
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Fat loss, weight control and weight maintenance
Increased metabolism
Increased calorie burning during workout
Increased calorie burning after exercise
Lowered resting blood pressure
Lowered risk of diabetes, heart disease, and some
types of cancer
• Improved blood lipid profile – raised HDL
Health Benefits of Resistance Training
(cont’d)
• Decreased risk for osteoporosis; increased bone mineral
content
• Improved structural and functional integrity of tendons,
ligaments, and joints
• Increases insulin sensitivity
• Combats depression
• Aids sleep
• Improved posture
• Enhanced physical activity experiences
• Improved personal independence
• Improved self-image, self-esteem
The Importance of Resistance Training
“Recent research suggests that the single most important step
to not just retard, but to reverse the aging process, is
strength training.”
“It is a myth that the older adult or elderly lose their ability to
respond to a strength training stimulus. … Strength levels
have tripled in well controlled and designed strength
studies using older adults and other studies have shown
strength improvements as high as 200 percent.”
Source: Brooks, Douglas. Effective strength training : analysis and technique for upper
body, lower body, and trunk exercises. Mammoth Lakes, Calif. : Moves International,
2001.
Muscular Strength
• Definition: the maximal force that a muscle or
muscle group can exert in a single contraction
Resistance Training and Aging
• Loss of muscle mass with age, result of inactivity
– 50% loss in muscle mass from age 20 to 90
• Leads to decreased quality of life
– Inability to carry out every day tasks
• Muscle mass can be increased with training
– Hypertrophy is not limited by age
Types of Resistance Training
• Dynamic – involves concentric and eccentric
contractions, may be isotonic or isokinetic
– concentric – muscle shortening
– eccentric – muscle lengthening, cause of muscle
soreness (DOMS)
• Static (isometric) – muscle contractions, but no
movement
– Causes an increase in blood pressure
– Specific to joint angle
Free Weights, Machines and Circuit Training
• Free weights
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Inexpensive and space efficient
Resistance changes throughout range of motion
Mimics everyday life
Develop joint stability
More difficult to isolate target muscle(s) – technique and form are
critical
• Machines
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Maintain resistance throughout range of motion
Does not require spotting
Must adjust the machine to fit the individual
Isolate target muscle(s) well
Free weights, machines and circuit training
• Circuit Training:
– Combination of resistance training and cardiovascular
endurance training
– Continuous activity, maintaining target heart rate for
30+ min.
– Increases muscular strength and endurance as well as
cardiovascular endurance, but not as well as training
specifically for those benefits
Exercise and Age Continuum
birth
Cardiovascular
Endurance
Training
Circuit Training
Resistance
Training
death
Atherosclerosis and other factors in CV disease develop early in life, therefore,
CV training to reduce the risk of CV disease is important at this stage. During
our middle years we are often pressed for time, working and raising families. In
order to maintain range of motion throughout the body and continue to reduce the
risk of CV disease, circuit training seems most appropriate. Finally, quality of
life in our last decades is often reduced a result of decreased mobility. Resistance
training can help combat this problem maintaining muscle mass and flexibility.
Principles of Resistance Training
• Stress-Rest
• Ceiling
• Specificity (SAID)
• Progressive Resistance
Overload
• FITT
• Maintenance
• Symmetry
• Reversibility
• Contraction Control
• Stress-Rest
– One day of exercise followed by one day of rest to
allow body to recover
– Optimal rest is 48 to 72 hours between workouts for
same muscle group
• Specificity (SAID)
– Specific Adaptation to Imposed Demands
– Only muscles used in the exercise will adapt, and they
will adapt to the specific demands imposed
– Low reps, high resistance = increase strength and size
• ( >3 sets and < 10 repetitions)
– High reps, low resistance = increase in endurance
• ( < 3 sets and > 15 repetitions)
FITT
• Frequency
– Depends on type of exercise
• Intensity
– Based on 1 RM (repetition maximum)
– Mostly trial and error
– Depends on training goals
• Time/Duration
– 20+ min (ACSM)
– Depends on individual program
• Type of Exercise
– Cardiovascular, strength, endurance, flexibility
• Symmetry
– Overall balanced development of body; body should be trained as
a whole unit
– Muscles aid in support of a joint; if more developed on one side,
likelihood of injury increases
– Functional and motor fitness – strength development should be
considered along with cardiovascular and stretching/flexibility
components
• Contraction Control
– Raising and lowering of weight must not involve momentum to
ensure work is done through muscular contraction
– Reduces risk of injury
• Ceiling
– As fitness level increases, strength and endurance increase
– As the potential/genetic fitness level is approached, increases in
fitness level decrease; participants will plateau and become bored
– Address through temporary training pause, change of exercises,
decrease in intensity to rest body
• Overload
– Muscles must be subjected to greater resistance than they normally
encounter, by increasing the weight
– 5% increase
• Maintenance
– Once training effect/goal has been reached, maintain fitness level
through reduction in training frequency; workouts 2x per week
instead of 3x a week
– Intensity and duration must remain the same
• Reversibility
– Benefits of training will be lost at 1/3 the rate gained; e.g., training
effect of 1 month will be completely lost after approx. 3 months
– Loss of training effect is eliminated by following the Maintenance
Principle
Ergogenic Aids
• Definition: Substances, techniques, or treatments
that theoretically enhance physical performance in
addition to the the effects of normal training
• Protein supplements, creatine, ginseng, chromium,
steroids, growth hormone, etc.
– Generally speaking there are no magic pills and
scientific evidence is often lacking. The most effective
performance enhancers often are illegal and/or have
serious side-effects
Flexibility
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Definition: the range of motion at a joint or series
of joints
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Influenced by 3 main factors:
1) Bony structure of the joint
2) Amount of tissue around the joint
3) Elasticity of the muscles, tendons, and ligaments that
cross over the joint
Other Factors Influencing Flexibility
• Age
– Tendons lose elasticity with age
– Range of motion declines in the mid-20s for males and
at about 30 for females
• Gender
• Physical activity and type of activity
– Physical inactivity has a greater influence on the loss of
flexibility than age
Types of stretching
• Ballistic
– Oldest type of stretching
– Makes use of repetitive bouncing movements
– Virtually abandoned by almost all experts in the field due to safety
concerns
• Static
– Very effective, relatively safe, popular method of stretching
– Involves passively stretching a muscle to the point of mild discomfort
– Holding time recommendations vary from 10 to 60 seconds; 20-30
seconds per stretch is normal
• Proprioceptive neuromuscular facilitation (PNF)
– Stretching technique involves partner actively stretching participant by
combination of altering contraction and relaxation of both agonist and
antagonist muscles
– Potentially more effective in producing greater flexibility
– Usually involves 10 second push phase, followed by a 10 second
relaxation phase, typically repeated several times
Guidelines for Safe Stretching
• Warm-up first, 5 – 10 minutes: this will decrease
risk of injury
• Stretch after workout – contrary to popular belief,
stretching before a workout does not decrease risk
of injury
• Stretch should feel uncomfortable but not painful
• For static stretches - hold stretch for 20 – 30
seconds
• Stretching daily is best
Stretching – Other Considerations
• More flexible individuals do not necessarily have less
incidence of injury
• More flexibility may actually lead to more injury because
joint integrity is compromised
• Greater flexibility may impair performance in sports that
do not require a high degree of flexibility – e.g., running
• Intense static stretching may reduce maximum force
production
• Persons participating in sports that require more than
average flexibility – gymnasts, dancers, figure skaters –
will experience performance benefits from stretching
Stretching – Other Considerations
(cont’d)
• Improved flexibility helps prevent back and other
orthopedic problems
• Individuals with muscular imbalances and postural
problems can benefit from stretching
• Stretching maintains flexibility which would
otherwise decline with age or inactivity due to
injury
Low-Back Pain
• Affects 80-90% of adults
• Causes:
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Excess body weight
Weak abdominal muscles
Weak and inflexible hamstrings
Poor posture
Lifting objects incorrectly
Work or sports related injuries
Diseases such as osteoporosis and osteoarthritis
Sedentary lifestyle
• Prevention
– Strengthen abdominal muscles and improve hamstring flexibility!