Download File - Fitness for life

L E S S O N
1
Muscle Fitness Facts
Lesson 1
Can You . . .
• . . . explain the differences between
strength, muscular endurance, and power?
• . . . describe how exercise principles apply
to muscle fitness?
• . . . describe the different types of muscle
contractions?
• . . . describe the characteristics of different
muscle fiber types?
How are strength, muscular
endurance, and power different?
Definitions
• Strength is the amount of force that a
muscle can exert.
• Muscular endurance is the ability to
contract muscles many times without tiring
or to hold a muscle contraction for a long
time without fatigue.
• Power is the ability to produce force quickly
(strength × speed = power).
Physical Activity Pyramid
Key Terms for Muscle Fitness
• Repetitions (reps): the number of
consecutive times you do an exercise
• Sets: one group of repetitions
• Example:
– Perform 8 push-ups, rest, perform another 8 pushups, rest, and finish with 8 more push-ups
– 3 sets of 8 reps (push-ups)
Does building strength require
different numbers of reps than
building muscular endurance?
Muscular Endurance–Strength
Continuum
Key Terms
• Muscle hypertrophy: growth in the size of
muscles
• 1-repetition maximum (1RM): the amount of
weight you can lift one time (best
assessment of strength)
• Calisthenics: exercises that use your body
weight as the resistance
How would you apply the basic
fitness training principles
(overload, progression, specificity,
rest and recovery) to muscle
fitness?
Principle of Overload
• Do more than before!
• Muscle fitness application: to become
stronger and improve muscular endurance,
strength, and power, a muscle must
contract harder than normal
Principle of Progression
• The amount and intensity of your exercise
should be increased gradually.
• Muscle fitness application: Gradually
increase load or resistance over time in
order to best improve your muscle fitness.
• If you try to use too much resistance too
soon, you can injure yourself.
Principle of Specificity
• You get what you train for!
• Muscle fitness application: The specific
type of training that you perform determines
which part of muscle fitness you build
(strength, endurance, or power).
(continued)
Principle of Specificity (continued)
• You build specific muscles by doing
exercises specifically for those muscles.
• Strength, muscular endurance, and power
each have their own FIT formula.
Principle of Rest and Recovery
• You need to give your muscles time to rest
and recover after a workout.
• Muscle fitness exercises for a specific
muscle group are typically performed on
only two or three days per week.
What are the two different types of
muscle contractions?
Muscle Contractions
1. Isometric contractions occur when
muscles contract and pull with equal force
in opposite directions so that no
movement occurs.
2. Isotonic contractions pull on your bones to
produce movement. There are two types:
– Concentric contractions: when the muscle shortens
– Eccentric contractions: when the muscle lengthens
What are the different types of
muscle fitness exercises?
Muscle Fitness Exercises
• Isometric exercise
– Pressing hands together, plank
• Isotonic exercise
– Biceps curl, push-up, bench press, squat
• Plyometrics
– Explosive jumping
• Isokinetic exercise
– Velocity of movement is kept constant by a machine
What are the different kinds of
muscle fibers?
Describe the characteristics of each.
Muscle Fibers
• Slow twitch: less force, resist fatigue
• Fast twitch: more force, fatigue quickly
• Intermediate fibers: characteristics of both
fibers
(continued)
Muscle Fibers (continued)
• All muscles have a blend of the different
muscle fibers.
• Muscle with more slow-twitch fibers have
better muscular endurance capabilities.
• Muscles with more fast-twitch fibers have
better strength and power capabilities.
Heredity and Muscle Fibers
• Genetics (heredity) determine the muscle fiber
composition of muscles.
• People who inherit a large number of fast-twitch muscle
fibers are especially likely to be good at activities
requiring sprinting and jumping.
• People who inherit a large number of slow-twitch
muscle fibers are likely to be good at activities requiring
sustained performance, such as distance running and
swimming.
(continued)
Heredity and Muscle Fibers
(continued)
• Training can affect muscle fiber function.
• Specific (anaerobic, strength, power) training can shift
slow-twitch fibers to have characteristics more like
intermediate fibers.
• Specific (aerobic) training can shift fast-twitch fibers to
have characteristics more like intermediate fibers.
• Regardless of your genes, you can increase your
strength, muscular endurance, and power with proper
training.
Absolute vs. Relative Strength
• Absolute strength is your 1RM score (the
most amount of force you can produce).
– Larger people typically have higher absolute strength.
– Absolute strength is important for some athletic positions.
• Relative strength is your strength adjusted
for body size (1RM divided by body weight).
– Relative strength is important for most athletes because
carrying too much body weight (even muscle) can impair
performance.
Science in Action: Resistance
Exercise Among Youth
• Not so long ago, some experts thought that
muscle fitness exercises were unsafe and
inappropriate for preteens and teens.
• Experts now provide evidence that, when
done properly, PRE provides health benefits
for teens similar to those for adults.
(continued)
Science in Action: Resistance
Exercise Among Youth (continued)
• Benefits of muscle fitness:
– Being able to work and play with little fatigue
– Reduced risk of chronic disease
– Reduced risk of injury and muscle pain or soreness,
– Improved muscle fitness and sport performance
– Psychological well-being
– Improved bone fitness that reduces the risk of osteoporosis
– Reduced risk of back pain
– Improved posture (look your best)