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Old 05-13-2006, 01:26 PM
EricT EricT is offline
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Section: 2.3.1 Why Bodybuilders Should Stretch
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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.

Section: 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. According to Kurz, 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.

Section: 2.4 Overflexibility

It is possible for the muscles of a joint to become too flexible. According to ‘SynerStretch’, 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]).


Section: 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

Section: 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]).


Section: 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). 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.


Section: 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 are active stretches.


Section: 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).


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].


Section: 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.


Section: 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, but according to ‘SynerStretch’ (the videotape), research has shown that this is not necessary. So you might as well make your stretching routine less time consuming.


Section: 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. At this point, according to ‘SynerStretch’, 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 to elongate 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.


Section: 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), ‘HFLTA’ recommends performing only one PNF technique per muscle group stretched in a given stretching session.
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If you act sanctimonious I will just list out your logical fallacies until you get pissed off and spew blasphemous remarks.

Last edited by EricT; 05-25-2006 at 01:33 PM.
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