Flexibility is enhanced by the controlled stretching of muscles that act on a particular joint. The primary strategy is to decrease the resistance to stretch(tension) within a tight muscle that you have targeted for increased range of motion. To do this, you repeatedly stretch the muscle and its two tendons of attachment to elongate them.
The three major types of stretching techniques are static, proprioceptive neuromuscular facilitation(PNF), and ballistic. Static stretching techniques involve the slow, gradual stretching of a muscle and its tendons, holding the muscle or muscle group at a point of mild discomfort(a burning sensation is felt within the muscle), followed by the slow return to the starting position.
When static stretching is done properly, it stimulates the tension receptors to allow the muscle being stretched to relax and permit the muscle to be stretched to greater length. Proprioceptive neuromuscular facilitation(PNF) techniques have been shown to be superior to other stretching techniques for improving flexibility; unfortunately, PNF techniques in their original form are quite complex and a certified athletic trainer or physical therapist may be required to help you perform them correctly:
Several PNF techniques(e.g., hold/relax, contract/relax) have been modified and simplified to the point that they can be performed with an exercise partner or even alone. With PNF techniques, a 6-second contraction of the muscle to be stretched is followed by an assisted stretch of 10 to 30 second’s duration. Ballistic stretching involves repeated bouncing motions, during which the muscle and tendon are rapidly stretched and returned to resting length. This process can be likened to taking a rubber band between two fingers, rapidly pulling it apart, md then releasing the tension, again and again. And just as a rubber band can snap in your fingers, if you apply too much tension, the muscle fibers being stretched in this way can be torn during these rapid movements. The risk of injury with ballistic stretching is so high that this type of stretching is no longer recommended for improving flexibility.
Of the three types of flexibility exercises, static stretches are probably the most commonly used. A major goal of static stretching is to cause permanent elongation of the targeted muscle or muscle group, thus permitting greater range of motion at a given joint. With static stretching, the end position is held for 10 to 30 seconds, and each of the major muscle groups should be stretched at least four times in close succession for optimal improvement. To achieve this goal, a comprehensive stretching program must be performed a minimum of two to three days a week.
Target heart rate Calculated as a percentage of maxi mum heart rate(220 minus age); heart rate(pulse) is taken during aerobic exercise to check if exercise intensity is at the desired level(e.g., 70 percent of maximum heart rate).
Flexibility The measure of the range of motion, or the amount of movement possible, at a particular joint.
Static stretching Techniques that gradually lengthen a muscle to an elongated position (to the point of discomfort) and hold that position for 10 to 30 seconds.