Thai Massage Article: - Stretching Techniques -
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Thai Massage Article: - Stretching Techniques -
STRETCHING AND FLEXIBILITY by Brad Appleton
Table of Contents
Introduction
Disclaimer
1 Physiology of Stretching
1.1 The Musculoskeletal System
1.2 Muscle Composition
1.2.1 How Muscles Contract
1.2.2 Fast and Slow Muscle Fibers
1.3 Connective Tissue
1.4 Cooperating Muscle Groups
1.5 Types of Muscle Contractions
1.6 What Happens When You Stretch
1.6.1 Proprioceptors
1.6.2 The Stretch Reflex
1.6.2.1 Components of the Stretch Reflex
1.6.3 The Lengthening Reaction
1.6.4 Reciprocal Inhibition
2 Flexibility
2.1 Types of Flexibility
2.2 Factors Limiting Flexibility
2.2.1 How Connective Tissue Affects Flexibility
2.2.2 How Aging Affects Flexibility
2.3 Strength and Flexibility
2.3.1 Why Bodybuilders Should Stretch
2.3.2 Why Contortionists Should Strengthen
2.4 Over flexibility
3 Types of Stretching
3.1 Ballistic Stretching
3.2 Dynamic Stretching
3.3 Active Stretching
3.4 Passive Stretching
3.5 Static Stretching
3.6 Isometric Stretching
3.6.1 How Isometric Stretching Works
3.7 PNF Stretching
3.7.1 How PNF Stretching Works
4 How to Stretch
4.1 Warming Up
4.1.1 General Warm-Up
4.1.1.1 Joint Rotations
4.1.1.2 Aerobic Activity
4.1.2 Warm-Up Stretching
4.1.2.1 Static Warm-Up Stretching
4.1.2.2 Dynamic Warm-Up Stretching
4.1.3 Sport-Specific Activity
4.2 Cooling Down
4.3 Massage
4.4 Elements of a Good Stretch
4.4.1 Isolation
4.4.2 Leverage
4.4.3 Risk
4.5 Some Risky Stretches
4.6 Duration, Counting, and Repetition
4.7 Breathing During Stretching
4.8 Exercise Order
4.9 When to Stretch
4.9.1 Early-Morning Stretching
4.10 Stretching With a Partner
4.11 Stretching to Increase Flexibility
4.12 Pain and Discomfort
4.12.1 Common Causes of Muscular Soreness
4.12.2 Stretching with Pain
4.12.3 Overstretching
4.13 Performing Splits
4.13.1 Common Problems When Performing Splits
4.13.2 The Front Split
4.13.3 The Side Split
4.13.4 Split-Stretching Machines
Appendix A References on Stretching
A.1 Recommendations
A.2 Additional Comments
Appendix B Working Toward the Splits
B.1 lower back stretches
B.2 lying buttock stretch
B.3 groin and inner-thigh stretch
B.4 seated leg stretches
B.4.1 seated calf stretch
B.4.2 seated hamstring stretch
B.4.3 seated inner-thigh stretch
B.5 psoas stretch
B.6 quadricep stretch
B.7 lying `V' stretch
Appendix C Normal Ranges of Joint Motion
C.1 Neck
C.2 Lumbar Spine
C.3 Shoulder
C.4 Elbow
C.5 Wrist
C.6 Hip
C.7 Knee
C.8 Ankle
Introduction
This document is a modest attempt to answer some frequently asked questions about stretching and flexibility. It is organized into chapters covering the following topics:
1. Physiology of Stretching
2. Flexibility
3. Types of Stretching
4. How to Stretch
Although each chapter may refer to sections in other chapters, it is not required that you read every chapter in the order presented. It is important, however, that you read the disclaimer before reading any other sections of this document. If you wish to skip around, numerous cross references are supplied in each section to help you find the concepts you may have missed.
Disclaimer:THE TECHNIQUES, IDEAS, AND SUGGESTIONS IN THIS DOCUMENT ARE NOT INTENDED AS A SUBSTITUTE FOR PROPER MEDICAL ADVICE! CONSULT YOUR PHYSICIAN OR HEALTH CARE PROFESSIONAL BEFORE PERFORMING ANY NEW EXERCISE OR EXERCISE TECHNIQUE, PARTICULARLY IF YOU ARE PREGNANT OR NURSING, OR IF YOU ARE ELDERLY, OR IF YOU HAVE ANY CHRONIC OR RECURRING CONDITIONS. ANY APPLICATION OF THE TECHNIQUES, IDEAS, AND SUGGESTIONS IN THIS DOCUMENT IS AT THE READER'S SOLE DISCRETION AND RISK.
THE AUTHOR AND PUBLISHER OF THIS DOCUMENT AND THEIR EMPLOYERS ARE NOT LIABLE OR RESPONSIBLE TO ANY PERSON OR ENTITY FOR ANY ERRORS CONTAINED IN THIS DOCUMENT, OR FOR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGE CAUSED OR ALLEGED TO BE CAUSED DIRECTLY OR INDIRECTLY BY THE INFORMATION CONTAINED IN THIS DOCUMENT.
1 Physiology of Stretching
The purpose of this chapter is to introduce you to some of the basic physiological concepts that come into play when a muscle is stretched.
Concepts will be introduced initially with a general overview and then will be discussed in further
detail.
1.1 The Musculoskeletal System
Together, muscles and bones comprise what is called the "musculoskeletal system" of the body. The bones provide posture and structural support for the body and the muscles provide the body with the ability to move (by contracting, and thus generating tension). The musculoskeletal system also provides protection for the body's internal organs. In order to serve their function, bones must be joined together by something. The point where bones connect to one another is called a "joint", and this connection is made mostly by "ligaments" (along with the help of muscles). Muscles are
attached to the bone by "tendons". Bones, tendons, and ligaments do not possess the ability (as muscles do) to make your body move. Muscles are very unique in this respect.
1.2 Muscle Composition
Muscles vary in shape and in size, and serve many different purposes. Most large muscles, like the hamstrings and quadriceps, control motion. Other muscles, like the heart, and the muscles of the inner ear, perform other functions. At the microscopic level however, all muscles share the same basic structure.
At the highest level, the (whole) muscle is composed of many strands of tissue called "fascicles". These are the strands of muscle that we see when we cut red meat or poultry. Each fascicle is composed of "fasciculi" which are bundles of "muscle fibers". The muscle fibers are in turn composed of tens of thousands of thread-like "myofybrils", which can contract, relax,
and elongate (lengthen). The myofybrils are (in turn) composed of up to millions of bands laid end-to-end called "sarcomeres". Each sarcomere is made of overlapping thick and thin filaments called "myofilaments". The thick and thin myofilaments are made up of "contractile proteins",
primarily actin and myosin.
1.2.1 How Muscles Contract
The way in which all these various levels of the muscle operate is as follows: Nerves connect the spinal column to the muscle. The place where the nerve and muscle meet is called the "neuromuscular junction". When an electrical signal crosses the neuromuscular junction, it is transmitted deep inside the muscle fibers. Inside the muscle fibers, the signal stimulates the flow of calcium which causes the thick and thin myofilaments to slide across one another. When this occurs, it causes the sarcomere to shorten, which generates force. When billions of sarcomeres in the muscle shorten all at once it results in a contraction of the entire muscle fiber.
When a muscle fiber contracts, it contracts completely. There is no such thing as a partially contracted muscle fiber. Muscle fibers are unable to vary the intensity of their contraction relative to the load against which they are acting. If this is so, then how does the force of a muscle
contraction vary in strength from strong to weak? What happens is that more muscle fibers are recruited, as they are needed, to perform the job at hand. The more muscle fibers that are recruited by the central nervous system, the stronger the force generated by the muscular contraction.
1.2.2 Fast and Slow Muscle Fibers
The energy which produces the calcium flow in the muscle fibers comes from "mitochondria", the part of the muscle cell that converts glucose (blood sugar) into energy. Different types of muscle fibers have different amounts of mitochondria. The more mitochondria in a muscle fiber, the more energy it is able to produce. Muscle fibers are categorized into "slow-twitch fibers" and "fast-twitch fibers". Slow-twitch fibers (also called "Type 1 muscle fibers") are slow to contract, but they are also very slow to fatigue. Fast-twitch fibers are very quick to contract and come in two
varieties: "Type 2A muscle fibers" which fatigue at an intermediate rate, and "Type 2B muscle fibers" which fatigue very quickly. The main reason the slow-twitch fibers are slow to fatigue is that they contain more mitochondria than fast-twitch fibers and hence are able to produce more
energy. Slow-twitch fibers are also smaller in diameter than fast-twitch fibers and have increased capillary blood flow around them. Because they have a smaller diameter and an increased blood flow, the slow-twitch fibers are able to deliver more oxygen and remove more waste products from the muscle fibers (which decreases their "fatigability").
These three muscle fiber types (Types 1, 2A, and 2B) are contained in allmuscles in varying amounts. Muscles that need to be contracted much of the time (like the heart) have a greater number of Type 1 (slow) fibers. When a muscle first starts to contract, it is primarily Type 1 fibers that are initially activated, then Type 2A and Type 2B fibers are activated (if needed) in that order. The fact that muscle fibers are "recruited" in this sequence is what provides the ability to execute brain commands with such fine-tuned tuned muscle responses. It also makes the Type 2B fibers
difficult to train because they are not activated until most of the Type 1 and Type 2A fibers have been recruited.
The best way to remember the difference between muscles with predominantly slow-twitch fibers and muscles with predominantly fast-twitch fibers is to think of "white meat" and "dark meat". Dark meat is dark because it has a greater number of slow-twitch
muscle fibers and hence a greater number of mitochondria, which are dark. White meat consists mostly of muscle fibers which are at rest much of the time but are frequently called on to engage in brief bouts of intense activity. This muscle tissue can contract quickly but is fast to fatigue
and slow to recover. White meat is lighter in color than dark meat because it contains fewer mitochondria.
1.3 Connective Tissue
Located all around the muscle and its fibers are "connective tissues".
Connective tissue is composed of a base substance and two kinds of protein based fiber. The two types of fiber are "collagenous connective tissue" and "elastic connective tissue". Collagenous connective tissue consists mostly of collagen (hence its name) and provides tensile strength. Elastic connective tissue consists mostly of elastin and (as you might guess from its name) provides elasticity. The base substance is called "mucopolysaccharide" and acts as both a lubricant (allowing the fibers to easily slide over one another), and as a glue (holding the fibers of the tissue together into bundles). The more elastic connective tissue there is around a joint, the greater the range of motion in that joint. Connective tissues are made up of tendons, ligaments, and the fascial sheaths that envelop, or bind down, muscles into separate groups. These fascial
sheaths, or "fascia", are named according to where they are located in the muscles:
"endomysium"
The innermost fascial sheath that envelops individual muscle fibers.
"perimysium"
The fascial sheath that binds groups of muscle fibers into individual
fasciculi (see Section 1.2 [Muscle Composition]).
"epimysium"
The outermost fascial sheath that binds entire fascicles (see Section
1.2 [Muscle Composition]).
These connective tissues help provide suppleness and tone to the muscles.
1.4 Cooperating Muscle Groups
When muscles cause a limb to move through the joint's range of motion, they usually act in the following cooperating groups:
"agonists"
These muscles cause the movement to occur. They create the normal range
of movement in a joint by contracting. Agonists are also referred to
as "prime movers" since they are the muscles that are primarily
responsible for generating the movement.
"antagonists"
These muscles act in opposition to the movement generated by the
agonists and are responsible for returning a limb to its initial
position.
"synergists"
These muscles perform, or assist in performing, the same set of joint
motion as the agonists. Synergists are sometimes referred to as
"neutralizers" because they help cancel out, or neutralize, extra
motion from the agonists to make sure that the force generated works
within the desired plane of motion.
"fixators"
These muscles provide the necessary support to assist in holding the
rest of the body in place while the movement occurs. Fixators are also
sometimes called "stabilizers".
As an example, when you flex your knee, your hamstring contracts, and, to some extent, so does your gastrocnemius (calf) and lower buttocks.
Meanwhile, your quadriceps are inhibited (relaxed and lengthened somewhat) so as not to resist the flexion (see Section 1.6.4 [Reciprocal Inhibition]). In this example, the hamstring serves as the agonist, or prime mover; the quadricep serves as the antagonist; and the calf and lower buttocks serve as the synergists. Agonists and antagonists are usually located on opposite sides of the affected joint (like your hamstrings and quadriceps, or your triceps and biceps), while synergists are usually located on the same side of the joint near the agonists. Larger muscles often call upon their smaller neighbors to function as synergists.
The following is a list of commonly used agonist/antagonist muscle pairs:
* pectorals/latissimus dorsi (pecs and lats)
* anterior deltoids/posterior deltoids (front and back shoulder)
* trapezius/deltoids (traps and delts)
* abdominals/spinal erectors (abs and lower-back)
* left and right external obliques (sides)
* quadriceps/hamstrings (quads and hams)
* shins/calves
* biceps/triceps
* forearm flexors/extensors
1.5 Types of Muscle Contractions
The contraction of a muscle does not necessarily imply that the muscle shortens; it only means that tension has been generated. Muscles can contract in the following ways:
"isometric contraction"
This is a contraction in which no movement takes place, because the
load on the muscle exceeds the tension generated by the contracting
muscle. This occurs when a muscle attempts to push or pull an
immovable object.
"isotonic contraction"
This is a contraction in which movement *does* take place, because the
tension generated by the contracting muscle exceeds the load on the
muscle. This occurs when you use your muscles to successfully push or
pull an object.
Isotonic contractions are further divided into two types:
"concentric contraction"
This is a contraction in which the muscle decreases in length
(shortens) against an opposing load, such as lifting a weight up.
"eccentric contraction"
This is a contraction in which the muscle increases in length
(lengthens) as it resists a load, such as lowering a weight down
in a slow, controlled fashion.
During a concentric contraction, the muscles that are shortening serve
as the agonists and hence do all of the work. During an eccentric
contraction the muscles that are lengthening serve as the agonists
(and do all of the work). See Section 1.4 [Cooperating Muscle Groups].
What Happens When You Stretch
The stretching of a muscle fiber begins with the sarcomere (see Section 1.2 [Muscle Composition]) the basic unit of contraction in the muscle fiber. As the sarcomere contracts, the area of overlap between the thick and thin myofilaments increases. As it stretches, this area of overlap decreases, allowing the muscle fiber to elongate. Once the muscle fiber is at its maximum resting length (all the sarcomeres are fully stretched), additional stretching places force on the surrounding connective tissue (see Section 1.3 [Connective Tissue]). As the tension increases, the collagen fibers in the connective tissue align themselves along the same line of force as the tension. Hence when you stretch, the muscle fiber is pulled out to its full length sarcomere by sarcomere, and then the connective tissue takes up the remaining slack. When this occurs, it helps to realign any disorganized fibers in the direction of the tension. This realignment is what helps to rehabilitate scarred tissue back to health.
When a muscle is stretched, some of its fibers lengthen, but other fibers may remain at rest. The current length of the entire muscle depends upon the number of stretched fibers (similar to the way that the total strength of a contracting muscle depends on the number of recruited fibers
contracting). You should think of "little pockets of fibers distributed throughout the muscle body stretching, and other fibers simply going along for the ride". The more fibers that are stretched, the greater the length developed by the stretched muscle.
1.6.1 Proprioceptors
The nerve endings that relay all the information about the musculoskeletal system to the central nervous system are called "proprioceptors".
Proprioceptors (also called "mechanoreceptors") are the source of all "proprioception": the perception of one's own body position and movement.
The proprioceptors detect any changes in physical displacement (movement or position) and any changes in tension, or force, within the body. They are found in all nerve endings of the joints, muscles, and tendons. The proprioceptors related to stretching are located in the tendons and in the muscle fibers.
There are two kinds of muscle fibers: "intrafusal muscle fibers" and "extrafusal muscle fibers". Extrafusil fibers are the ones that contain myofibrils (see Section 1.2 [Muscle Composition]) and are what is usually meant when we talk about muscle fibers. Intrafusal fibers are also called
"muscle spindles" and lie parallel to the extrafusal fibers. Muscle spindles, or "stretch receptors", are the primary proprioceptors in the muscle. Another proprioceptor that comes into play during stretching is located in the tendon near the end of the muscle fiber and is called the "golgi tendon organ". A third type of proprioceptor, called a "pacinian corpuscle", is located close to the golgi tendon organ and is responsible for detecting changes in movement and pressure within the body.
When the extrafusal fibers of a muscle lengthen, so do the intrafusal fibers (muscle spindles). The muscle spindle contains two different typesof fibers (or stretch receptors) which are sensitive to the change in muscle length and the rate of change in muscle length. When muscles contract it places tension on the tendons where the Golgi tendon organ is located. The Golgi tendon organ is sensitive to the change in tension and the rate of change of the tension.
1.6.2 The Stretch Reflex
When the muscle is stretched, so is the muscle spindle. The muscle spindle records the change in length (and how fast) and sends signals to the spine which convey this information. This triggers the "stretch reflex" (also called the "myotatic reflex") which attempts to resist the change in muscle length by causing the stretched muscle to contract. The more sudden the change in muscle length, the stronger the muscle contractions will be (plyometric, or "jump", training is based on this fact). This basic function of the muscle spindle helps to maintain muscle tone and to protect the body from injury.
One of the reasons for holding a stretch for a prolonged period of time is that as you hold the muscle in a stretched position, the muscle spindle habituates (becomes accustomed to the new length) and reduces its signaling. Gradually, you can train your stretch receptors to allow
greater lengthening of the muscles.
Some sources suggest that with extensive training, the stretch reflex of certain muscles can be controlled so that there is little or no reflex contraction in response to a sudden stretch. While this type of control provides the opportunity for the greatest gains in flexibility, it also provides the greatest risk of injury if used improperly. Only consummate professional athletes and dancers at the top of their sport (or art) are believed to actually possess this level of muscular control.
1.6.2.1 Components of the Stretch Reflex
The stretch reflex has both a dynamic component and a static component.
The static component of the stretch reflex persists as long as the muscle is being stretched. The dynamic component of the stretch reflex (which can be very powerful) lasts for only a moment and is in response to the initial sudden increase in muscle length. The reason that the stretch reflex has
two components is because there are actually two kinds of intrafusal muscle fibers: "nuclear chain fibers", which are responsible for the static component; and "nuclear bag fibers", which are responsible for the dynamic component.
Nuclear chain fibers are long and thin, and lengthen steadily when stretched. When these fibers are stretched, the stretch reflex nerves increase their firing rates (signaling) as their length steadily increases. This is the static component of the stretch reflex.
Nuclear bag fibers bulge out at the middle, where they are the most elastic. The stretch-sensing nerve ending for these fibers is wrapped around this middle area, which lengthens rapidly when the fiber is stretched. The outer-middle areas, in contrast, act like they are filled with viscous fluid; they resist fast stretching, then gradually extend under prolonged tension. So, when a fast stretch is demanded of these fibers, the middle takes most of the stretch at first; then, as the outer-middle parts extend, the middle can shorten somewhat. So the nerve that senses stretching in these fibers fires rapidly with the onset of a fast stretch, then slows as the middle section of the fiber is allowed to shorten again. This is the dynamic component of the stretch reflex: a strong signal to contract at the onset of a rapid increase in muscle length, followed by slightly "higher than normal" signaling which gradually decreases as the rate of change of the muscle length decreases.
1.6.3 The Lengthening Reaction
When muscles contract (possibly due to the stretch reflex), they produce tension at the point where the muscle is connected to the tendon, where the Golgi tendon organ is located. The Golgi tendon organ records the change in tension, and the rate of change of the tension, and sends signals to thespine to convey this information (see Section 1.6.1 [Proprioceptors]).
When this tension exceeds a certain threshold, it triggers the "lengthening reaction" which inhibits the muscles from contracting and causes them to relax. Other names for this reflex are the "inverse myotatic reflex", "autogenic inhibition", and the "clasped-knife reflex". This basic
function of the Golgi tendon organ helps to protect the muscles, tendons, and ligaments from injury. The lengthening reaction is possible only because the signaling of Golgi tendon organ to the spinal cord is powerful enough to overcome the signaling of the muscle spindles telling the muscle
to contract.
Another reason for holding a stretch for a prolonged period of time is to allow this lengthening reaction to occur, thus helping the stretched muscles to relax. It is easier to stretch, or lengthen, a muscle when it is not trying to contract.
1.6.4 Reciprocal Inhibition
When an agonist contracts, in order to cause the desired motion, it usually forces the antagonists to relax (see Section 1.4 [Cooperating Muscle Groups]). This phenomenon is called "reciprocal inhibition" because the antagonists are inhibited from contracting. This is sometimes called
"reciprocal innervation" but that term is really a misnomer since it is the agonists which inhibit (relax) the antagonists. The antagonists do *not* actually innervate (cause the contraction of) the agonists.
Such inhibition of the antagonistic muscles is not necessarily required.
In fact, co-contraction can occur. When you perform a sit-up, one would normally assume that the stomach muscles inhibit the contraction of the muscles in the lumbar, or lower, region of the back. In this particular instance however, the back muscles (spinal erectors) also contract. This is
one reason why sit-ups are good for strengthening the back as well as the stomach.
When stretching, it is easier to stretch a muscle that is relaxed than to stretch a muscle that is contracting. By taking advantage of the situations when reciprocal inhibition *does* occur, you can get a more effective stretch by inducing the antagonists to relax during the stretch due to the contraction of the agonists. You also want to relax any muscles used as synergists by the muscle you are trying to stretch. For example, when you stretch your calf, you want to contract the shin muscles (the antagonists of the calf) by flexing your foot. However, the hamstrings use
the calf as a synergist so you want to also relax the hamstrings by contracting the quadricep (i.e., keeping your leg straight).
2 Flexibility
Flexibility is defined by Gummerson as "the absolute range of movement in a joint or series of joints that is attainable in a momentary effort with the help of a partner or a piece of equipment." This definition tells us that flexibility is not something general but is specific to a particular joint
or set of joints. In other words, it is a myth that some people are innately flexible throughout their entire body. Being flexible in one particular area or joint does not necessarily imply being flexible in
another. Being "loose" in the upper body does not mean you will have a "loose" lower body. Furthermore, flexibility in a joint is also "specific to the action performed at the joint (the ability to do front splits doesn't imply the ability to do side splits even though both actions occur at the hip)."
2.1 Types of Flexibility
Many people are unaware of the fact that there are different types of flexibility. These different types of flexibility are grouped according to the various types of activities involved in athletic training. The ones which involve motion are called "dynamic" and the ones which do not are
called "static". The different types of flexibility (according to Kurz) are:
"dynamic flexibility"
Dynamic flexibility (also called "kinetic flexibility") is the ability
to perform dynamic (or kinetic) movements of the muscles to bring a
limb through its full range of motion in the joints.
"static-active flexibility"
Static-active flexibility (also called "active flexibility") is the
ability to assume and maintain extended positions using only the
tension of the agonists and synergists while the antagonists are being
stretched (see Section 1.4 [Cooperating Muscle Groups]). For example,
lifting the leg and keeping it high without any external support
(other than from your own leg muscles).
"static-passive flexibility"
Static-passive flexibility (also called "passive flexibility") is the
ability to assume extended positions and then maintain them using only
your weight, the support of your limbs, or some other apparatus (such
as a chair or a barrel). Note that the ability to maintain the position
does not come solely from your muscles, as it does with static-active
flexibility. Being able to perform the splits is an example of
static-passive flexibility.
Research has shown that active flexibility is more closely related to the level of sports achievement than is passive flexibility. Active flexibility is harder to develop than passive flexibility (which is what
most people think of as "flexibility"); not only does active flexibility require passive flexibility in order to assume an initial extended position, it also requires muscle strength to be able to hold and maintain that position.
2.2 Factors Limiting Flexibility
Flexibility (mobility) is affected by the following factors:
* Internal influences
- the type of joint (some joints simply aren't meant to be flexible)
- the internal resistance within a joint
- bony structures which limit movement
- the elasticity of muscle tissue (muscle tissue that is scarred
due to a previous injury is not very elastic)
- the elasticity of tendons and ligaments (ligaments do not stretch
much and tendons should not stretch at all)
- the elasticity of skin (skin actually has some degree of
elasticity, but not much)
- the ability of a muscle to relax and contract to achieve the
greatest range of movement
- the temperature of the joint and associated tissues (joints and
muscles offer better flexibility at body temperatures that are 1
to 2 degrees higher than normal)
* External influences
- the temperature of the place where one is training (a warmer
temperature is more conducive to increased flexibility)
- the time of day (most people are more flexible in the afternoon
than in the morning, peaking from about 2:30pm-4pm)
- the stage in the recovery process of a joint (or muscle) after
injury (injured joints and muscles will usually offer a lesser
degree of flexibility than healthy ones)
- age (pre-adolescents are generally more flexible than adults)
- gender (females are generally more flexible than males)
- one's ability to perform a particular exercise (practice makes
perfect)
- one's commitment to achieving flexibility
- the restrictions of any clothing or equipment
Water is an important dietary element with regard to flexibility. Increased water intake is believed to contribute to increased mobility, as well as increased total body relaxation.
The more common factors which limit one's flexibility are: bone structure, muscle mass, excess fatty tissue, and connective tissue (and, of course, physical injury or disability).
Depending on the type of joint involved and its present condition (is it healthy?), the bone structure of a particular joint places very noticeable limits on flexibility. This is a common way in which age can be a factor limiting flexibility since older joints tend not to be as healthy as younger ones.
Muscle mass can be a factor when the muscle is so heavily developed that it interferes with the ability to take the adjacent joints through their complete range of motion (for example, large hamstrings limit the ability to fully bend the knees). Excess fatty tissue imposes a similar restriction.
The majority of "flexibility" work should involve performing exercises designed to reduce the internal resistance offered by soft connective tissues (see Section 1.3 [Connective Tissue]). Most stretching exercises attempt to accomplish this goal and can be performed by almost anyone,
regardless of age or gender.
2.2.1 How Connective Tissue Affects Flexibility
The resistance to lengthening that is offered by a muscle is dependent upon its connective tissues: When the muscle elongates, the surrounding connective tissues become more taut (see Section 1.3 [Connective Tissue]). Also, inactivity of certain muscles or joints can cause chemical changes in
connective tissue which restrict flexibility. Each type of tissue plays a certain role in joint stiffness: "The joint capsule (i.e., the saclike structure that encloses the ends of bones) and ligamentsare the most important factors, accounting for 47 percent of the stiffness, followed by the muscle's fascia (41 percent), the tendons (10 percent), and skin (2 percent)".
M. Alter goes on to say that efforts to increase flexibility should be directed at the muscle's fascia however. This is because it has the most elastic tissue, and because ligaments and tendons (since they have less elastic tissue) are not intended to stretched very much at all. Overstretching them may weaken the joint's integrity and cause destabilization (which increases the risk of injury).
When connective tissue is overused, the tissue becomes fatigued and may tear, which also limits flexibility. When connective tissue is unused or under used, it provides significant resistance and limits flexibility. The elastin begins to fray and loses some of its elasticity, and the collagen
increases in stiffness and in density. Aging has some of the same effects on connective tissue that lack of use has.
2.2.2 How Aging Affects Flexibility
With appropriate training, flexibility can, and should, be developed at all ages. This does not imply, however, that flexibility can be developed at the same rate by everyone. In general, the older you are, the longer it will take to develop the desired level of flexibility. Hopefully, you'll be more patient if you're older.
According to M. Alter, the main reason we become less flexible as we get older is a result of certain changes that take place in our connective tissues. As we age, our bodies gradually dehydrate to some extent. It is believed that "stretching stimulates the production or retention of
lubricants between the connective tissue fibers, thus preventing the formation of adhesions". Hence, exercise can delay some of the loss of flexibility that occurs due to the aging process.
Some of the physical changes attributed to aging are the following:
* An increased amount of calcium deposits, adhesions, and cross-links in
the body
* An increase in the level of fragmentation and dehydration
* Changes in the chemical structure of the tissues.
* Loss of "suppleness" due to the replacement of muscle fibers with
fatty, collagenous fibers.
This does *not* mean that you should give up trying to achieve flexibility if you are old or inflexible. It just means that you need to work harder, and more carefully, for a longer period of time when attempting to increase flexibility. Increases in the ability of muscle tissues and connective tissues to elongate (stretch) can be achieved at any age.
2.3 Strength and Flexibility
Strength training and flexibility training should go hand in hand. It is a common misconception that there must always be a trade-off between flexibility and strength. Obviously, if you neglect flexibility training altogether in order to train for strength then you are certainly sacrificing flexibility (and vice versa). However, performing exercises for both strength and flexibility need not sacrifice either one. As a matter of fact, flexibility training and strength training can actually enhance one another.
2.3.1 Why Bodybuilders Should Stretch
One of the best times to stretch is right after a strength workout such as weightlifting. Static stretching of fatigued muscles (see Section 3.5 [Static Stretching]) performed immediately following the exercise(s) that caused the fatigue, helps not only to increase flexibility, but also
enhances the promotion of muscular development (muscle growth), and will actually help decrease the level of post-exercise soreness. Here's why:
After you have used weights (or other means) to overload and fatigue your muscles, your muscles retain a "pump" and are shortened somewhat. This "shortening" is due mostly to the repetition of intense muscle activity that often only takes the muscle through part of its full range of motion.
This "pump" makes the muscle appear bigger. The "pumped" muscle is also full of lactic acid and other by-products from exhaustive exercise. If the muscle is not stretched afterward, it will retain this decreased range of motion (it sort of "forgets" how to make itself as long as it could) and
the buildup of lactic acid will cause post-exercise soreness. Static stretching of the "pumped" muscle helps it to become "looser", and to "remember" its full range of movement. It also helps to remove lactic acid and other waste-products from the muscle. While it is true that stretching
the "pumped" muscle will make it appear visibly smaller, it does not decrease the muscle's size or inhibit muscle growth. It merely reduces the "tightness" (contraction) of the muscles so that they do not "bulge" as much.
Also, strenuous workouts will often cause damage to the muscle's connective tissue. The tissue heals in 1 to 2 days but it is believed that the tissues heal at a shorter length (decreasing muscular development as well as flexibility). To prevent the tissues from healing at a shorter length, physiologists recommend static stretching after strength workouts.
2.3.2 Why Contortionists Should Strengthen
You should be "tempering" (or balancing) your flexibility training with strength training (and vice versa). Do not perform stretching exercises for a given muscle group without also performing strength exercises for that same group of muscles. Judy Alter, in her book `Stretch and Strengthen', recommends stretching muscles after performing strength exercises, and performing strength exercises for every muscle you stretch. In other words: "Strengthen what you stretch, and stretch after you strengthen!"
The reason for this is that flexibility training on a regular basis causes connective tissues to stretch which in turn causes them to loosen (become less taut) and elongate. When the connective tissue of a muscle is weak, it is more likely to become damaged due to overstretching, or sudden, powerful muscular contractions. The likelihood of such injury can be prevented by strengthening the muscles bound by the connective tissue. Kurz suggests dynamic strength training consisting of light dynamic exercises with weights (lots of reps, not too much weight), and isometric tension
exercises. If you also lift weights, dynamic strength training for a muscle should occur *before* subjecting that muscle to an intense weightlifting workout. This helps to pre-exhaust the muscle first, making it easier (and faster) to achieve the desired overload in an intense strength workout. Attempting to perform dynamic strength training *after* an intense weightlifting workout would be largely ineffective.
If you are working on increasing (or maintaining) flexibility then it is *very* important that your strength exercises force your muscles to take the joints through their full range of motion. Repeating movements that do not employ a full range of motion in the joints (like cycling, certain weightlifting techniques, and pushups) can cause of shortening of the muscles surrounding the joints. This is because the nervous control of length and tension in the muscles are set at what is
repeated most strongly and/or most frequently.
2.4 Overflexibility
It is possible for the muscles of a joint to become too flexible.
There is a tradeoff between flexibility and stability. As you get "looser" or more limber in a particular joint, less support is given to the joint by its surrounding muscles. Excessive
flexibility can be just as bad as not enough because both increase your risk of injury.
Once a muscle has reached its absolute maximum length, attempting to stretch the muscle further only serves to stretch the ligaments and put undue stress upon the tendons (two things that you do *not* want to stretch). Ligaments will tear when stretched more than 6% of their normal
length. Tendons are not even supposed to be able to lengthen. Even when stretched ligaments and tendons do not tear, loose joints and/or a decrease in the joint's stability can occur (thus vastly increasing your risk of injury).
Once you have achieved the desired level of flexibility for a muscle or set of muscles and have maintained that level for a solid week, you should discontinue any isometric or PNF stretching of that muscle until some of its flexibility is lost (see Section 3.6 [Isometric Stretching], and see
Section 3.7 [PNF Stretching]).
3 Types of Stretching
Just as there are different types of flexibility, there are also different types of stretching. Stretches are either dynamic (meaning they involve motion) or static (meaning they involve no motion). Dynamic stretches affect dynamic flexibility and static stretches affect static flexibility
(and dynamic flexibility to some degree).
The different types of stretching are:
1. ballistic stretching
2. dynamic stretching
3. active stretching
4. passive (or relaxed) stretching
5. static stretching
6. isometric stretching
7. PNF stretching
3.1 Ballistic Stretching
Ballistic stretching uses the momentum of a moving body or a limb in an attempt to force it beyond its normal range of motion. This is stretching, or "warming up", by bouncing into (or out of) a stretched position, using the stretched muscles as a spring which pulls you out of the stretched
position. (e.g. bouncing down repeatedly to touch your toes.) This type of stretching is not considered useful and can lead to injury. It does not allow your muscles to adjust to, and relax in, the stretched position. It may instead cause them to tighten up by repeatedly activating the stretch
reflex (see Section 1.6.2 [The Stretch Reflex]).
3.2 Dynamic Stretching
"Dynamic stretching", according to Kurz, "involves moving parts of your body and gradually increasing reach, speed of movement, or both." Do not confuse dynamic stretching with ballistic stretching! Dynamic stretching consists of controlled leg and arm swings that take you (gently!) to the limits of your range of motion. Ballistic stretches involve trying to force a part of the body *beyond* its range of motion. In dynamic stretches, there are no bounces or "jerky" movements. An example of dynamic stretching would be slow, controlled leg swings, arm swings, or torso twists.
Dynamic stretching improves dynamic flexibility and is quite useful as part of your warm-up for an active or aerobic workout (such as a dance or martial-arts class) or Thai massage. See Section 4.1 [Warming Up].
According to Kurz, dynamic stretching exercises should be performed in sets of 8-12 repetitions. Be sure to stop when and if you feel tired. Tired muscles have less elasticity which decreases the range of motion used in your movements. Continuing to exercise when you are tired serves only to
reset the nervous control of your muscle length at the reduced range of motion used in the exercise (and will cause a loss of flexibility). Once you attain a maximal range of motion for a joint in any direction you should stop doing that movement during that workout. Tired and overworked
muscles won't attain a full range of motion and the muscle's kinesthetic memory will remember the repeated shorted range of motion, which you will then have to overcome before you can make further progress.
3.3 Active Stretching
"Active stretching" is also referred to as "static-active stretching". An active stretch is one where you assume a position and then hold it there with no assistance other than using the strength of your agonist muscles (see Section 1.4 [Cooperating Muscle Groups]). For example, bringing your
leg up high and then holding it there without anything (other than your leg muscles themselves) to keep the leg in that extended position. The tension of the agonists in an active stretch helps to relax the muscles being stretched (the antagonists) by reciprocal inhibition (see Section 1.6.4
[Reciprocal Inhibition]).
Active stretching increases active flexibility and strengthens the agonistic muscles. Active stretches are usually quite difficult to hold and maintain for more than 10 seconds and rarely need to be held any longer than 15 seconds.
Many of the movements (or stretches) found in various forms of yoga and Thai Yoga are active stretches.
3.4 Passive Stretching
"Passive stretching" is also referred to as "relaxed stretching", and as "static-passive stretching". A passive stretch is one where you assume a position and hold it with some other part of your body, or with the assistance of a partner or some other apparatus. For example, bringing your leg up high and then holding it there with your hand. The splits is an example of a passive stretch (in this case the floor is the "apparatus" that you use to maintain your extended position). Thai massage is another excellent example of passive stretching.
Slow, relaxed stretching is useful in relieving spasms in muscles that are healing after an injury. Obviously, you should check with your doctor first to see if it is okay to attempt to stretch the injured muscles (see Section 4.12 [Pain and Discomfort]).
Relaxed stretching is also very good for "cooling down" after a workout and helps reduce post-workout muscle fatigue, and soreness. See Section 4.2 [Cooling Down].
3.5 Static Stretching
Many people use the term "passive stretching" and "static stretching" interchangeably. However, there are a number of people who make a distinction between the two. According to M. Alter, "Static stretching" consists of stretching a muscle (or group of muscles) to its farthest point
and then maintaining or holding that position, whereas "Passive stretching" consists of a relaxed person who is relaxed (passive) while some external force (either a person or an apparatus) brings the joint through its range of motion.
Notice that the definition of passive stretching given in the previous section encompasses *both* of the above definitions. Throughout this document, when the term "static stretching" or "passive stretching" is used, its intended meaning is the definition of passive stretching as described in the previous section. You should be aware of these alternative meanings, however, when looking at other references on stretching.
3.6 Isometric Stretching
"Isometric stretching" is a type of static stretching (meaning it does not use motion) which involves the resistance of muscle groups through isometric contractions (tensing) of the stretched muscles (see Section 1.5 [Types of Muscle Contractions]). The use of isometric stretching is one of
the fastest ways to develop increased static-passive flexibility and is much more effective than either passive stretching or active stretching alone. Isometric stretches also help to develop strength in the "tensed" muscles (which helps to develop static-active flexibility), and seems to
decrease the amount of pain usually associated with stretching.
The most common ways to provide the needed resistance for an isometric stretch are to apply resistance manually to one's own limbs, to have a partner apply the resistance, or to use an apparatus such as a wall (or the floor) to provide resistance.
An example of manual resistance would be holding onto the ball of your foot to keep it from flexing while you are using the muscles of your calf to try and straighten your instep so that the toes are pointed.
An example of using a partner to provide resistance would be having a partner hold your leg up high (and keep it there) while you attempt to force your leg back down to the ground.
An example of using the wall to provide resistance would be the well known "push-the-wall" calf-stretch where you are actively attempting to move the wall (even though you know you can't).
Isometric stretching is *not* recommended for children and adolescents whose bones are still growing. These people are usually already flexible enough that the strong stretches produced by the isometric contraction have a much higher risk of damaging tendons and connective tissue. Kurz
strongly recommends preceding any isometric stretch of a muscle with dynamic strength training for the muscle to be stretched. A full session of isometric stretching makes a lot of demands on the muscles being stretched and should not be performed more than once per day for a given group of
muscles (ideally, no more than once every 36 hours).
The proper way to perform an isometric stretch is as follows:
1. Assume the position of a passive stretch for the desired muscle.
2. Next, tense the stretched muscle for 7-15 seconds (resisting against
some force that will not move, like the floor or a partner).
3. Finally, relax the muscle for at least 20 seconds.
Some people seem to recommend holding the isometric contraction for longer than 15 seconds, research has shown that this is not necessary. So you might as well make your stretching routine less time consuming.
3.6.1 How Isometric Stretching Works
Recall from our previous discussion (see Section 1.2.1 [How Muscles Contract]) that there is no such thing as a partially contracted muscle fiber: when a muscle is contracted, some of the fibers contract and some remain at rest (more fibers are recruited as the load on the muscle
increases). Similarly, when a muscle is stretched, some of the fibers are elongated and some remain at rest (see Section 1.6 [What Happens When You Stretch]). During an isometric contraction, some of the resting fibers are being pulled upon from both ends by the muscles that are contracting. The result is that some of those resting fibers stretch!
Normally, the handful of fibers that stretch during an isometric contraction are not very significant. The true effectiveness of the isometric contraction occurs when a muscle that is already in a stretched position is subjected to an isometric contraction. In this case, some of the muscle fibers are already stretched before the contraction, and, if held long enough, the initial passive stretch overcomes the stretch reflex (see Section 1.6.2 [The Stretch Reflex]) and triggers the lengthening
reaction (see Section 1.6.3 [The Lengthening Reaction]), inhibiting the stretched fibers from contracting. When you isometrically contracted, some resting fibers would contract and some resting fibers would stretch. Furthermore, many of the fibers already stretching may be prevented from contracting by the inverse myotatic reflex (the lengthening reaction) and would stretch even
more. When the isometric contraction is completed, the contracting fibers return to their resting length but the stretched fibers would remember their stretched length and (for a period of time) retain the ability toelongate past their previous limit. This enables the entire muscle to stretch beyonds its initial maximum and results in increased flexibility.
The reason that the stretched fibers develop and retain the ability to stretch beyond their normal limit during an isometric stretch has to do with the muscle spindles (see Section 1.6.1 [Proprioceptors]): The signal which tells the muscle to contract voluntarily, also tells the muscle
spindle's (intrafusal) muscle fibers to shorten, increasing sensitivity of the stretch reflex. This mechanism normally maintains the sensitivity of the muscle spindle as the muscle shortens during contraction. This allows the muscle spindles to habituate (become accustomed) to an even
further-lengthened position.
3.7 PNF Stretching
PNF stretching is currently the fastest and most effective way known to increase static-passive flexibility. PNF is an acronym for "proprioceptive neuromuscular facilitation". It is not really a type of stretching but is a technique of combining passive stretching (see Section 3.4 [Passive
Stretching]) and isometric stretching (see Section 3.6 [Isometric Stretching]) in order to achieve maximum static flexibility. Actually, the term PNF stretching is itself a misnomer. PNF was initially developed as a method of rehabilitating stroke victims. PNF refers to any of several
"post-isometric relaxation" stretching techniques in which a muscle group is passively stretched, then contracts isometrically against resistance while in the stretched position, and then is passively stretched again through the resulting increased range of motion. PNF stretching usually
employs the use of a partner to provide resistance against the isometric contraction and then later to passively take the joint through its increased range of motion. It may be performed, however, without a partner, although it is usually more effective with a partner's assistance.
Most PNF stretching techniques employ "isometric agonist contraction/relaxation" where the stretched muscles are contracted isometrically and then relaxed. Some PNF techniques also employ "isometric antagonist contraction" where the antagonists of the stretched muscles are
contracted. In all cases, it is important to note that the stretched muscle should be rested (and relaxed) for at least 20 seconds before performing another PNF technique. The most common PNF stretching techniques are:
the "hold-relax"
This technique is also called the "contract-relax". After assuming an
initial passive stretch, the muscle being stretched is isometrically
contracted for 7-15 seconds, after which the muscle is briefly relaxed
for 2-3 seconds, and then immediately subjected to a passive stretch
which stretches the muscle even further than the initial passive
stretch. This final passive stretch is held for 10-15 seconds. The
muscle is then relaxed for 20 seconds before performing another PNF
technique.
the "hold-relax-contract"
This technique is also called the "contract-relax-contract", and the
"contract-relax-antagonist-contract" (or "CRAC"). It involves
performing two isometric contractions: first of the agonists, then, of
the antagonists. The first part is similar to the hold-relax where,
after assuming an initial passive stretch, the stretched muscle is
isometrically contracted for 7-15 seconds. Then the muscle is relaxed
while its antagonist immediately performs an isometric contraction that
is held for 7-15 seconds. The muscles are then relaxed for 20 seconds
before performing another PNF technique.
the "hold-relax-swing"
This technique (and a similar technique called the "hold-relax-bounce")
actually involves the use of dynamic or ballistic stretches in
conjunction with static and isometric stretches. It is *very* risky,
and is successfully used only by the most advanced of athletes and
dancers that have managed to achieve a high level of control over
their muscle stretch reflex (see Section 1.6.2 [The Stretch Reflex]).
It is similar to the hold-relax technique except that a dynamic or
ballistic stretch is employed in place of the final passive stretch.
Notice that in the hold-relax-contract, there is no final passive stretch. It is replaced by the antagonist-contraction which, via reciprocal inhibition (see Section 1.6.4 [Reciprocal Inhibition]), serves to relax and further stretch the muscle that was subjected to the initial passive
stretch. Because there is no final passive stretch, this PNF technique is considered one of the safest PNF techniques to perform (it is less likely to result in torn muscle tissue). Some people like to make the technique even more intense by adding the final passive stretch after the second
isometric contraction. Although this can result in greater flexibility gains, it also increases the likelihood of injury.
Even more risky are dynamic and ballistic PNF stretching techniques like the hold-relax-swing, and the hold-relax-bounce. If you are not a professional athlete or dancer, you probably have no business attempting either of these techniques (the likelihood of injury is just too great).
Even professionals should not attempt these techniques without the guidance of a professional coach or training advisor. These two techniques have the greatest potential for rapid flexibility gains, but only when performed by people who have a sufficiently high level of control of the stretch reflex in the muscles that are being stretched.
Like isometric stretching (see Section 3.6 [Isometric Stretching]), PNF stretching is also not recommended for children and people whose bones are still growing (for the same reasons. Also like isometric stretching, PNF stretching helps strengthen the muscles that are contracted and therefore is good for increasing active flexibility as well as passive flexibility. Furthermore, as with isometric stretching, PNF stretching is very strenuous and should be performed for a given muscle group no more than once per day (ideally, no more than once per 36 hour period).
The initial recommended procedure for PNF stretching is to perform the desired PNF technique 3-5 times for a given muscle group (resting 20 seconds between each repetition). However, `HFLTA' cites a 1987 study whose results suggest that performing 3-5 repetitions of a PNF technique
for a given muscle group is not necessarily any more effective than performing the technique only once. As a result, in order to decrease the amount of time taken up by your stretching routine (without decreasing its effectiveness), it is recommended tp perform only one PNF technique per muscle group stretched in a given stretching session.
3.7.1 How PNF Stretching Works
Remember that during an isometric stretch, when the muscle performing the isometric contraction is relaxed, it retains its ability to stretch beyond its initial maximum length (see Section 3.6.1 [How Isometric Stretching Works]). Well, PNF tries to take immediate advantage of this increased
range of motion by immediately subjecting the contracted muscle to a passive stretch.
The isometric contraction of the stretched muscle accomplishes several
things:
1. As explained previously (see Section 3.6.1 [How Isometric Stretching
Works]), it helps to train the stretch receptors of the muscle spindle
to immediately accommodate a greater muscle length.
2. The intense muscle contraction, and the fact that it is maintained for
a period of time, serves to fatigue many of the fast-twitch fibers of
the contracting muscles (see Section 1.2.2 [Fast and Slow Muscle
Fibers]). This makes it harder for the fatigued muscle fibers to
contract in resistance to a subsequent stretch (see Section 1.6.2 [The
Stretch Reflex]).
3. The tension generated by the contraction activates the golgi tendon
organ (see Section 1.6.1 [Proprioceptors]), which inhibits contraction
of the muscle via the lengthening reaction (see Section 1.6.3 [The
Lengthening Reaction]). Voluntary contraction during a stretch
increases tension on the muscle, activating the Golgi tendon organs
more than the stretch alone. So, when the voluntary contraction is
stopped, the muscle is even more inhibited from contracting against a
subsequent stretch.
PNF stretching techniques take advantage of the sudden "vulnerability" of he muscle and its increased range of motion by using the period of time mmediately following the isometric contraction to train the stretch receptors to get used to this new, increased, range of muscle length. This is what the final passive (or in some cases, dynamic) stretch accomplishes.
4 How to Stretch
When done properly, stretching can do more than just increase flexibility.
Benefits of stretching include:
* enhanced physical fitness
* enhanced ability to learn and perform skilled movements
* increased mental and physical relaxation
* enhanced development of body awareness
* reduced risk of injury to joints, muscles, and tendons
* reduced muscular soreness
* reduced muscular tension
* increased suppleness due to stimulation of the production of chemicals
which lubricate connective tissues (see Section 1.3 [Connective
Tissue])
* reduced severity of painful menstruation ("dysmenorrhea") in females
Unfortunately, even those who stretch do not always stretch properly and hence do not reap some or all of these benefits. Some of the most common mistakes made when stretching are:
* improper warm-up
* inadequate rest between workouts
* overstretching
* performing the wrong exercises
* performing exercises in the wrong (or sub-optimal) sequence
In this chapter, we will try to show you how to avoid these problems, and others, and present some of the most effective methods for realizing all the benefits of stretching.
4.1 Warming Up
Stretching is *not* warming up! It is, however, a very important part of warming up. Warming up is quite literally the process of "warming up" (i.e., raising your core body temperature). A proper warm-up should raise your body temperature by one or two degrees Celsius (1.4 to 2.8 degrees
Fahrenheit) and is divided into three phases:
1. general warm-up
2. stretching
3. sport-specific activity
It is very important that you perform the general warm-up *before* you stretch. It is *not* a good idea to attempt to stretch before your muscles are warm (something which the general warm-up accomplishes).
Warming up can do more than just loosen stiff muscles; when done properly, it can actually improve performance. On the other hand, an improper warm-up, or no warm-up at all, can greatly increase your risk of injury from engaging in athletic activities.
It is important to note that active stretches and isometric stretches should *not* be part of your warm-up because they are often counterproductive. The goals of the warm-up are (according to Kurz): "an increased awareness, improved coordination, improved elasticity and contractibility of muscles, and a greater efficiency of the respiratory and cardiovascular systems." Active stretches and isometric stretches do not help achieve these goals because they are likely to cause the stretched muscles to be too tired to properly perform the athletic activity for which you are preparing your body.
4.1.1 General Warm-Up
The general warm-up is divided into two parts:
1. joint rotations
2. aerobic activity
These two activities should be performed in the order specified above.
4.1.1.1 Joint Rotations
The general warm-up should begin with joint-rotations, starting either from your toes and working your way up, or from your fingers and working yourway down. This facilitates joint motion by lubricating the entire joint with synovial fluid. Such lubrication permits your joints to function more
easily when called upon to participate in your athletic activity. You should perform slow circular movements, both clockwise and counter-clockwise, until the joint seems to move smoothly. You should rotate the following (in the order given, or in the reverse order):
1. fingers and knuckles
2. wrists
3. elbows
4. shoulders
5. neck
6. trunk/waist
7. hips
8. legs
9. knees
10. ankles
11. toes
4.1.1.2 Aerobic Activity
After you have performed the joint rotations, you should engage in at least five minutes of aerobic activity such as jogging, jumping rope, or any other activity that will cause a similar increase in your cardiovascular output (i.e., get your blood pumping). The purpose of this is to raise your core body temperature and get your blood flowing. Increased blood flow in the muscles improves muscle performance and flexibility and reduces the likelihood of injury.
4.1.2 Warm-Up Stretching
The stretching phase of your warm-up should consist of two parts:
1. static stretching
2. dynamic stretching
It is important that static stretches be performed *before* any dynamic stretches in your warm-up. Dynamic stretching can often result in overstretching, which damages the muscles (see Section 4.12.3 [Overstretching]). Performing static stretches first will help reduce this risk of injury.
4.1.2.1 Static Warm-Up Stretching
Once the general warm-up has been completed, the muscles are warmer and more elastic. Immediately following your general warm-up, you should engage in some slow, relaxed, static stretching (see Section 3.5 [Static Stretching]). You should start with your back, followed by your upper body and lower body, stretching your muscles in the following order (see Section 4.8 [Exercise Order]):
1. back
2. sides (external obliques)
3. neck
4. forearms and wrists
5. triceps
6. chest
7. buttocks
8. groin (adductors)
9. thighs (quadriceps and abductors)
10. calves
11. shins
12. hamstrings
13. instep
Some good static stretches for these various muscles may be found in most books about stretching. See Section Appendix A [References on Stretching].
Unfortunately, not everyone has the time to stretch all these muscles before a workout. If you are one such person, you should at least take the time to stretch all the muscles that will be heavily used during your workout.
4.1.2.2 Dynamic Warm-Up Stretching
Once you have performed your static stretches, you should engage in some light dynamic stretching: leg-raises, and arm-swings in all directions (see Section 3.2 [Dynamic Stretching]). According to Kurz, you should do "as many sets as it takes to reach your maximum range of motion in any given direction", but do not work your muscles to the point of fatigue. Remember
- this is just a warm-up, the real workout comes later.
Some people are surprised to find that dynamic stretching has a place in the warm-up. But think about it: you are "warming up" for a workout that is (usually) going to involve a lot of dynamic activity. It makes sense that you should perform some dynamic exercises to increase your dynamic
flexibility.
4.1.3 Sport-Specific Activity
The last part of your warm-up should be devoted to performing movements that are a "watered-down" version of the movements that you will be performing during your athletic activity. The last phase of a warm-up should consist of the same movements that will be used during the athletic event but at a reduced intensity. Such "sport-specific activity" is beneficial because it improves coordination, balance, strength, and response time, and may reduce the risk of injury.
4.2 Cooling Down
Stretching is *not* a legitimate means of cooling down. It is only part of the process. After you have completed your workout, the best way to reduce muscle fatigue and soreness (caused by the production of lactic acid from your maximal or near-maximal muscle exertion) is to perform a light
"warm-down". This warm-down is similar to the second half of your warm-up (but in the reverse order).The warm-down consists of the following phases:
1. sport-specific activity
2. dynamic stretching
3. static stretching
Ideally, you should start your warm-down with about 10-20 minutes of sport-specific activity (perhaps only a little more intense than in your warm-up). In reality however, you may not always have 10-20 minutes to spare at the end of your workout. You should, however, attempt to perform
at least 5 minutes of sport-specific activity in this case. The sport-specific activity should immediately be followed by stretching:
First perform some light dynamic stretches until your heart rate slows down to its normal rate, then perform some static stretches. Sport-specific activity, followed by stretching, can reduce cramping, tightening, and soreness in fatigued muscles and will make you feel better.
According to `HFLTA', "light warm-down exercise immediately following maximal exertion is a better way of clearing lactic acid from the blood than complete rest." Furthermore, if you are still sore the next day, a light warm-up or warm-down is a good way to reduce lingering muscle
tightness and soreness even when not performed immediately after a workout.
See Section 4.12 [Pain and Discomfort].
4.3 Massage
Many people are aware of the beneficial role that massage can play in both strength training and flexibility training. Massaging a muscle, or group of muscles, immediately prior to performing stretching or strength exercises for those muscles, has some of the following benefits:
increased blood flow
The massaging of the muscles helps to warm-up those muscles, increasing their blood flow and improving their circulation.
relaxation of the massaged muscles
The massaged muscles are more relaxed. This is particularly helpful when you are about to stretch those muscles. It can also help relieve painful muscle cramps.
removal of metabolic waste
The massaging action, and the improved circulation and blood flow which results, helps to remove waste products, such as lactic acid, from the muscles. This is useful for relieving post-exercise soreness.
Because of these benefits, you may wish to make massage a regular part of your stretching program: immediately before each stretch you perform, massage the muscles you are about to stretch.
4.4 Elements of a Good Stretch
There are three factors to consider when determining the effectiveness of a particular stretching exercise:
1. Isolation
2. Leverage
3. Risk
4.4.1 Isolation
Ideally, a particular stretch should work only the muscles you are trying to stretch. Isolating the muscles worked by a given stretch means that you do not have to worry about having to overcome the resistance offered by more than one group of muscles. In general, the fewer muscles you try to
stretch at once, the better. For example, you are better off trying to stretch one hamstring at a time than both hamstrings at once. By isolating the muscle you are stretching, you experience resistance from fewer muscle groups, which gives you greater control over the stretch and allows you to more easily change its intensity. As it turns out, the splits is not one of the best stretching exercises. Not only does it stretch several different muscle groups all at once, it also stretches them in both legs at once.
4.4.2 Leverage
Having leverage during a stretch means having sufficient control over how intense the stretch becomes, and how fast. If you have good leverage, not only are you better able to achieve the desired intensity of the stretch, but you do not need to apply as much force to your outstretched limb in order to effectively increase the intensity of the stretch. This gives you greater control.
The best stretches (those which are most effective) provide the greatest mechanical advantage over the stretched muscle. By using good leverage, it becomes easier to overcome the
resistance of inflexible muscles (the same is true of isolation). Many stretching exercises (good and bad) can be made easier and more effective simply by adjusting them to provide greater leverage.
4.4.3 Risk
Although a stretch may be very effective in terms of providing the athlete with ample leverage and isolation, the potential risk of injury from performing the stretch must be taken into consideration.
Even an exercise offering great leverage and great isolation may still be a poor choice to perform. Some exercises can simply cause too much stress to the joints (which may result in injury).
They may involve rotations that strain tendons or ligaments, or put pressure on the disks of the back, or contain some other twist or turn that may cause injury to seemingly unrelated parts of the body.
4.5 Some Risky Stretches
The following stretches (many of which are commonly performed) are considered risky (M. Alter uses the term `X'-rated) due to the fact that they have a very high risk of injury for the athlete that performs them.
This does not mean that these stretches should never be performed. However, great care should be used when attempting any of these stretches. Unless you are an advanced athlete or are being coached by a qualified instructor (such as a certified Yoga instructor, physical therapist, or professional trainer), you can probably do without them (or find alternative stretching exercises to perform). When performed correctly with the aid of an instructor however, some of these stretches can be quite beneficial. Each of these stretches is illustrated in detail in the section `X-Rated Exercises' of M. Alter:
"the Thai yoga plough"
In this exercise, you lie down on your back and then try to sweep your legs up and over, trying to touch your knees to your ears. This position places excessive stress on the lower back, and on the discs of the spine. Not to mention the fact that it compresses the lungs and heart, and makes it very difficult to breathe. This particular exercise also stretches a region that is frequently flexed as a result of improper posture. This stretch is a prime example of an exercise that is very easy to do incorrectly. However, with proper instruction and attention to body position and alignment, this stretch can be performed successfully with a minimal amount of risk and can actually improve spinal health and mobility.
"the traditional Thai backbend"
In this exercise, your back is maximally arched with the soles of your feet and the palms of your hands both flat on the floor, and your neck tilted back. This position squeezes (compresses) the spinal discs and pinches nerve fibers in your back.
"the traditional Thai hurdler's stretch"
This exercise has you sit on the ground with one leg straight in front of you, and with the other leg fully flexed (bent) behind you, as you lean back and stretch the quadricep of the flexed leg. The two legged version of this stretch is even worse for you, and involves fully bending both legs behind you on either side. The reason this stretch is harmful is that it stretches the medial ligaments of the knee (remember, stretching ligaments and tendons is *bad*) and crushes the meniscus. It can also result in slipping of the knee cap from being twisted and compressed.
"straight-legged toe touches"
In this stretch, your legs are straight (either together or spread apart) and your back is bent over while you attempt to touch your toes or the floor. If you do not have the ability to support much of your weight with your hands when performing this exercise, your knees are likely to hyperextend. This position can also place a great deal of pressure on the vertebrae of the lower lumbar. Furthermore, if you choose to have your legs spread apart, it places more stress on the knees, which can sometimes result in permanent deformity.
"torso twists"
Performing sudden, intense twists of the torso, while in an upright (erect) position can tear tissue (by exceeding the momentum absorbing capacity of the stretched tissues) and can strain the ligaments of the knee.
"inverted stretches"
This is any stretch where you "hang upside down". Staying inverted for too long increases your blood pressure and may even rupture blood vessels (particularly in the eyes). Inverted positions are especially discouraged for anyone with spinal problems.
4.6 Duration, Counting, and Repetition
One thing many people seem to disagree about is how long to hold a passive stretch in its position. Various sources seem to suggest that they should be held for as little as 10 seconds to as long as a full minute (or even several minutes). The truth is that no one really seems to know for sure.
According to `HFLTA' there exists some controversy over how long a stretch should be held. Many researchers recommend 30-60 seconds. For the hamstrings, research suggests that 15 seconds may be sufficient, but it is not yet known whether 15 seconds is sufficient for any other muscle group.
A good common ground seems to be about 20 seconds. Children, and people whose bones are still growing, do not need to hold a passive stretch this long (and, in fact, Kurz strongly discourages it). Holding the stretch for about 7-10 seconds should be sufficient for this younger group of people.
A number of people like to count (either out loud or to themselves) while they stretch. While counting during a stretch is not, by itself, particularly important ... what is important is the setting of a definite goal for each stretching exercise performed. Counting during a stretch helps many people achieve this goal.
Many sources also suggest that passive stretches should be performed in sets of 2-5 repetitions with a 15-30 second rest in between each stretch.
4.7 Breathing During Stretching
Proper breathing control is important for a successful stretch. Proper breathing helps to relax the body, increases blood flow throughout the body, and helps to mechanically remove lactic acid and other by-products of exercise.
You should be taking slow, relaxed breaths when you stretch, trying to exhale as the muscle is stretching. Some even recommend increasing the intensity of the stretch only while exhaling, holding the stretch in its current position at all other times (this doesn't apply to isometric
stretching).
The proper way to breathe is to inhale slowly through the nose, expanding the abdomen (not the chest); hold the breath a moment; then exhale slowly through the nose or mouth. Inhaling through the nose has several purposes including cleaning the air and insuring proper temperature and humidity for oxygen transfer into the lungs. The breath should be natural and the diaphragm and abdomen should remain soft. There should be no force of the breath. Some experts seem to prefer exhaling through the nose (as opposed to through the mouth) saying that exhaling through the mouth causes depression on the heart and that problems will ensue over the long term.
The rate of breathing should be controlled through the use of the glottis in the back of the throat. This produces a very soft "hm-m-m-mn" sound inside the throat as opposed to a sniffing sound in the nasal sinuses. The exhalation should be controlled in a similar manner, but if you are exhaling through the mouth, it should be with more of an "ah-h-h-h-h" sound, like a sigh of relief.
As you breathe in, the diaphragm presses downward on the internal organs and their associated blood vessels, squeezing the blood out of them. As you exhale, the abdomen, its organs and muscles, and their blood vessels flood with new blood. This rhythmic contraction and expansion of the abdominal blood vessels is partially responsible for the circulation of blood in the body. Also, the rhythmic pumping action helps to remove waste products from the muscles in the torso. This pumping action is referred to as the "respiratory pump". The respiratory pump is important during
stretching because increased blood flow to the stretched muscles improves their elasticity, and increases the rate at which lactic acid is purged from them.
4.8 Exercise Order
Many people are unaware of the fact that the order in which you perform your stretching exercises is important. Quite often, when we perform a particular stretch, it actually stretches more than one group of muscles: the muscles that the stretch is primarily intended for, and other supporting muscles that are also stretched but which do not receive the "brunt" of the stretch. These supporting muscles usually function as synergists for the muscles being stretched (see Section 1.4 [Cooperating Muscle Groups]). This is the basis behind a principle called the "interdependency of muscle groups".
Before performing a stretch intended for a particular muscle, but which actually stretches several muscles, you should first stretch each of that muscle's synergists. The benefit of this is that you are able to better stretch the primary muscles by not allowing the supporting muscles the
opportunity to be a limiting factor in how "good" a stretch you can attain for a particular exercise.
Ideally, it is best to perform a stretch that isolates a particular muscle group, but this is not always possible. "by organizing the exercises within a stretching routine according to the principle of interdependency of muscle groups, you minimize the effort required to perform the routine, and maximize the effectiveness of the individual exercises." "synergism": "combining elements to create a whole that is greater than the mere sum of its parts."
For example, a stretch intended primarily for the hamstrings may also make some demands upon the calves and buttocks (and even the lower back) but mostly, it stretches the hamstrings. In this case, it would be beneficial to stretch the lower back, buttocks, and calves first (in that order, using
stretches intended primarily for those muscles) before they need to be used in a stretch that is intended primarily for the hamstrings.
As a general rule, yo