Basic Principles:
Muscular strength and endurance are
considered one of the components of fitness. The development of muscular
strength and endurance helps to improve and functional physical capacity, as
per Hoeger et al5. Other benefits in developing and/or improving
muscular strength and endurance are: greater work efficiency, less chances of
muscle injury, reduced risk of low back pain, improved sports performance,
quicker recovery from hard work, and improved ability to meet emergency
situations 3. This article is about the basic principles underlying
the design of a muscular strength and/or endurance-training program.
In designing a resistance /
strength training program, there are basic principles to follow. The first
being that in order to develop some strength, the muscle must be made to work
beyond what it is used to. This is the principle of overload1, 2, 3.
How much overload to give will be discussed later on. This is one of the most basic principles in
developing strength.
When the body is given an overload,
it takes the body some time to adjust to that particular workload. After the body
has adjusted to that workload, it will be time to increase it again. This is
second principle, the principle of progresssion1, 2, 3. The load /
intensity must be increased over time as the body adapts to the previous load.
This is to continuously produce improvements over time.
Some authors combine the first
two principles, progressive overload3. But basically, it is still
the same two principles rolled into one.
The third principle is
specificity1, 2, 3.
This principle simply states that that type of stress placed on the body will
produce specific adaptations. For example, if one wants to increase strength of
the chest area, then an exercise such as the bench press, should be given. If
the person is involved in sports, then giving exercise, which closely mimic the
movement, should be prescribed. If, for example, the jumping ability of a
player needs to be improved, then giving exercises such as the squat and the
power exercises, such as the hang clean or the clean and jerk, should be part
of the program.
The fourth principle is on rest
and recovery. The ACSM recommends at least 48 hours between workouts for each
muscle group 2, 7. This allows the muscle time to recover from the
previous workout. The rest principle also refers to rest in between sets and exercise
in a single workout.
Components
of a workout session:
It is suggested that all exercise
training sessions have the following components: warm-up, stretching,
conditioning, and cool down phases. The ACSM recommends that the warm-up be of
low to moderate intensity aerobic and/or muscular endurance activity for about
5 to 10 minutes. This is to in increase the body temperature and reduce the
potential for after exercise muscle soreness. It also allows the body to adjust
to the change in physiological and biomechanical demands placed on the body
during the actual exercise proper. 3, 8
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Fig. 1 A football
player doing a dynamic warm-up
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The stretching phase is distinct
from the warm-up and cool-down and can be performed either after the warm-up or
cool down phases.8
The conditioning phase, or the
exercise proper, is where one performs the aerobic or resistance exercise
itself. If the person is involved in sports, sport related activity is also
performed here 3,6,8. This will be discussed below.
The last portion is the cool-down
phase. Similar recommendations as the warm-up, 5 to 10 minutes of low to
moderate intensity aerobic or muscular endurance activity. The purpose is to
return the heart rate (HR) and blood pressure (BP) to resting, or close to
resting levels, and allow removal of metabolic by-products from the muscles. 3,
8
Program
Design:
In designing a resistance training
workout, it is recommended to use the FITT principle. FITT stands for:
F –
Frequency
I –
Intensity
T – Time
T – Type
Frequency
stands for how often should one work out 4. For general fitness, the
ACSM recommends that strength training should be done two to three times a
week. That is non-consecutive days for most major muscle groups. Two consecutive days can be done if a split
type of workout is given. A split type of workout is when two different muscle
groups are exercised of consecutive days.8 For example, working the
muscles of the upper extremity on day 1. Day 2 will then consist of working the
muscles of the lower extremity. The third day will be the rest day.
For general fitness, the ACSM
recommends a moderate load of around 60% to 80% of the 1 RM 8. This
should allow around 8 to 12 repetitions per exercise. This intensity is
suggested for people aged less than 50 to 60 years of age. For older (50 to 60
years of age) and/or more deconditioned individuals, the suggested intensity
should allow a repetition range of 10-15 repetitions 8. This would
correspond to a score of 5 to 6 on a 10-point RPE scale 5. The
suggested intensity for that particular repetition range, as per the ACSM, 60%
to 70% of 1-RM 8. The NSCA, on the other hand, recommends < 67%
of 1-RM 1,2.
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Fig. 2 Borg Scale
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Type stands for the mode of exercise 4.
While for some authors, this a given because the obvious exercise is
resistance/strength training. However, for Fahey et al, the type of resistance
exercise should also be considered 4. Fahey et al suggests exercises
for the neck, upper back, shoulder, arms, chest, abdomen, lower back, thighs,
buttocks, and calves 4. The ACSM recommends exercises for the major
muscle groups: chest, shoulders, abdomen, back, hips, legs, and arms 5, 8.
While the NSCA recommends exercises for the following muscle groups: chest,
shoulders, upper back, hips/thighs, biceps, triceps, abdominals, and calves 2.
Regardless
of what you want to follow, the suggestion is that there should be 8 to 10
exercises that would cover every major muscle group 5, 8. About one
exercise per muscle group at the basic level, or beginning lifter 2.
Exercises suggested should include multijoint , or compound, exercises that
involve more than one muscle group 8. An intermediate lifter may
include two exercises per muscle group 2.
Time
denotes the length of time one performs the exercises, or workout 5.
It can also be the amount of time one performs a particular exercise 3, 4
.
If we speak about the amount of time
to perform a particular exercise, we talk about the number of repetitions, or
reps, and the number of times these repetitions are repeated, or sets. The
choice of the number of reps depends upon the goal of the individual. At the
basic level, when training beginners, the suggested training sets and reps are:
1 set of 8-12 reps for young adults; 1 set of 10 to 15 reps for adults greater
than 50 years old 3. This is the threshold of training. Optimally,
there should be 1-3 sets of the former and latter 3.
As for the length of time to perform
a workout, the ACSM suggests a workout time of no more than hour. As higher
dropout rates are associated with longer, more difficult workouts 5.
This is applicable to beginners or older adults.
In prescribing strength training
exercise to beginners and older adults, a little common sense goes a long way.
Prescribing too much too soon, especially for untrained people will produce a
high dropout rate. While the intensity of the exercise is prescribed in the
article, one must not assume that the trainees can life the load immediately.
It may be prudent to start at a much lower intensity with one set in the
beginning and work it up to the prescribed set and rep range. This is to allow
the beginner to learn the movement and build strength up without too much
muscle soreness involved.
Bibliography:
1. Baechle, Thomas R.
and Roger W. Earle “Essentials of Strength Training Conditioning 3rd
Ed.” 2008
2. Baechle, Thomas R. and Roger W. Earle “Essentials
of Personal Training” 2004
3. Corbin, Charles B., Gregory J. Welk, William R.
Corbin, Karen A. Welk, and Cara L. Sidman “Concepts of
Fitness and Wellness 9th
edition” 2011
4. Fahey, Thomas D.,
Paul M. Insel, and Walton T. Roth “Fit and Well: Core Concepts and Labs in
Physical
Fitness and Wellness 9th edition” 2011
5. Franklin, Barry A.
senior editor “ACSM’s Guidelines for Testing and Prescription 6th
ed.” 2000
6. Hoeger, Werner W. K. and Sharon A. Hoeger
“Lifetime Physical Fitness and Wellness 11th edition” 2011
7. Wilmore, Jack H.,
David L. Costill and W. Larry Kenney “ Physiology of Sport and Exercise Fourth
Edition” 2008
8. Thompson, Walter R,
senior editor “ACSM’s Guidelines for Exercise Testing and Prescription 8th
ed.”
2010
