This document discusses the muscular system and strength training. It explains that muscles work with connective tissues like tendons, and describes the series elastic component (SEC) and parallel elastic component (PEC) of the muscle model. The document also discusses the different types of muscle contractions (isometric, concentric, eccentric), muscle actions like agonist and antagonist muscles, and the importance of the nervous system in strength and muscle development. Functional strength training aims to improve abilities like speed and endurance, while structural training focuses more on muscle hypertrophy.

1. Strength and the Muscular
System
Supertraining, Chapter 1

2. A Model of the Muscle Complex
It is relatively meaningless to
discuss muscle action without
considering the role played by
the connective tissues
associated with muscle.
Connective tissues occur in
the sheaths of muscle and its
sub-units at all levels.

3. The Muscle Model
Series Elastic Component (SEC)
Tendon, Myofilaments, Z-Discs, Titin
Basically, the tendons and actual muscle fibers
Parallel Elastic Component (PEC)
Muscle Sheaths and sarcolemma

4. A Better Picture

5. Muscle Model Forces
PEC is responsible for force exerted by a
relaxed muscle when it is stretched
beyond its resting length
SEC is put under tension by the force
developed in an actively contracted
muscle

6. Who Cares?
You should care for 2 reasons….well 3.
1. So you can sound smart when talking to
exercise physiologists.
2. So you know that more than just the muscle
is involved in human movement, elastic parts
are very important too!
3. So you know that static stretching influences
the PEC more than the SEC and that static
ROM is different than dynamic ROM.

7. Muscle Actions:
Basic Terminology
Agonist: Prime movers in an action
Antagonist: Muscles acting in opposition to
agonist
Stabilizers: Muscles that stabilize a body
segment while other muscles carry out a
movement

8. Muscle Action Examples:
Agonist: In a leg extension exercise, the
quadriceps are going to be agonists of the
exercise.

9. Muscle Action Examples:
Antagonist: In a leg extension on a
machine, the hamstrings would be the
antagonists to the movement. If the
hamstrings were firing during the upward
portion of the movement, the action would
be severely affected, or could not happen.

10. Types of Muscle Contraction
Isometric
Concentric
Eccentric

11. Types of Muscle Contraction
Isometric Contraction
There is ALWAYS an isometric phase of any
lift, jump, throw, etc.
The isometric phase of a slow movement, such
as a barbell squat will take much longer than
the isometric phase of a vertical jump.
The brief isometric contraction between
eccentric and concentric phases in plyometrics
is of great importance!

12. Types of Muscle Contraction
Concentric contraction
This is the part of contraction where positive
work is done. The power of this contraction is
often influenced by the previous two phases of
muscle contraction (eccentric/concentric)
Eccentric (yielding) contraction
Can produce 30-40% greater muscle tension
than other two contractions
DOMS (delayed onset muscle soreness)
producer

13. Eccentric Contractions
The eccentric phase can store more
energy than the other two phases.
Because of the elastic properties of the
muscle-tendon complex, the more energy
stored during the eccentric phase, the
more energy is released in the concentric
phase.
We will get to this more later when we talk
about the Stretch-Shortening Cycle in
detail.

14. A Dynamic example

15. An Example:

16. An Example:

17. The Fundamental Principle of Strength
Training
The production and increase of strength
both depend on neuromuscular processes.
Strength is not primarily a function of
muscle size, but one of the appropriate
muscles powerfully contracted by effective
nervous stimulation.
Example: Tara Nott, Olympic Weightlifter

18. The Fundamental Principle of Strength
Training
Basically the nervous system ultimately
controls the outcome of a training
program.

19. Nervous System
The central nervous system (CNS) is the
part of the nervous system that functions
to coordinate the activity of all parts of the
bodies of multicellular organisms
(Wikipedia)
CNS is a term you should be familiar with!

20. The Neuromuscular System and Strength
 Stimulation (training) of the nervous system
produces two basic effects on the body:
Functional muscle action
Muscle hypertrophy
(hypertrophy=increase in size of the muscle)
 With this in mind there are two basic types of
strength training:
Functional strength training
Structural strength training

21. Functional vs. Structural
Structural strength training would aim
specifically at producing muscle
hypertrophy (increase in muscle size).
Functional strength training is associated
with improving static strength, speed-
strength, muscle endurance, and reactive
ability.

22. A functional/structural scale
Here is a scale of exercises for a track and
field sprinter for the quadriceps muscle

23. A note about functional training
 Functional training is fairly simple, it involves
motor movements that are close to that of the
primary sport. It can also be simply playing the
given sport. Typically these movements will be
low or high amplitude jumping exercises,
general calisthenics, sprints of varying
distances, and other elastic exercises.
 In the early stages of training or during
stagnation at an advanced level, the functional
stages of training should precede „structural‟
training work.

24. Don‟t get carried away when you hear
“functional”
 Some trainers take
functional training out of
context
 Trying to add too much
„complexity‟ to an
exercise or making it
overly sport specific can
alter firing patterns. Also,
too much element of
balance in an exercise
will take away from force
production ability.
Not “Functional” Training

25. A breakdown of „functional‟ training:
4 Processes involved
Intermuscular coordination
Intramuscular coordination
Facilitory and inhibitory reflexive processes
Motor learning

26. Intermuscular Coordination
Coordination between different muscle
groups.
This involves the synchronizing or
sequencing of muscles in certain
movements.
Some muscles might be inhibited from
cooperating, while some might be
disinhibited from cooperating in a
movement.

27. Intramuscular Coordination
 This is the improvement
of coordination of muscle
fibers in the same
muscle.
 Increase in number of
muscle fibers activated or
deactivated
 Rate Coding: control of
tension by modifying the
frequency that the fibers
fire at
 Pattern Encoding: control
of tension by synchronizing
the firing of different types
of muscle (e.g. slow or fast
twitch fibers….sprint
example)

28. Motor Learning
 Motor learning is the process of programming
the CNS to carry out specific movement
tasks.
 Most gains found early in a resistance
program are due to motor learning!
 Motor learning will continue as the intensity
and complexity of the exercise increases,
because skill in demanding conditions is
much different than skill in basic conditions.

29. CNS is important in training, so what?
The way you train can affect the change of
the CNS.
Strength training on machines can modify
the circuitry and programming of the brain
and thereby reduce the functional
capability of the muscles used for a
specific movement.
HIT trainees would disagree

30. CNS is important in training, so what?
Because of the rapid changes produced in
the brain by repeated stimuli, even short
periods of inappropriate patterns of
strength training can be detrimental to
sporting performance
Example: If I am a sprinter and train with a
50lb vest for 3 weeks, and then compete
in a big meet, my motor patterns will be
altered, and I won‟t do very well.

31. CNS is important in training, so what?
Over reliance on ergogenic devices like
belts, gloves, knee wraps and heel
wedges can modify the neuromuscular
system so that safe and effective training
without them can become difficult

32. CNS is important in training, so what?
 The existence of
individual style reveals
that each person will
program the CNS in
subtly different ways.
This means that an
attempt to place a
stereotypes, general
pattern of movement
might prevent an athlete
from reaching their full
potential
An Example of 2 Jumping Styles

33. Structural and Functional
Determinants of Strength
Structural Factors
Cross-sectional area of muscle
Density of muscle fibers per unit cross-sectional
area. (Muscle density)
Efficiency of mechanical leverage across the
joint
Muscle insertion
Pennation angle of muscle

34. Functional Determinants of Strength
The number of muscle fibers contracting
simultaneously
The rate of contraction of muscle fibers
The efficiency of synchronisation of the
firing of muscle fibers
The conduction velocity in the nerve fibers

35. Functional Determinants
The degree of inhibition of muscle fibers
which do not contribute to the movement
The proportion of large diameter muscle
fibers active
The efficiency of cooperation between
different types of muscle fiber (fast and
slow)

36. Functional Determinants
The efficiency of the stretch-shortening
cycle
The excitation threshold of the nerve fibers
supplying the muscles
The initial length of the muscles before
contraction