Flexibility refers to the joint’s ability to move through a full range of motion. Factors that affect flexibility include genetic inheritance, the joint structure itself, connective tissue elasticity within muscles, tendons or skin surrounding a joint, strength of opposing muscle groups, body type, age, activity level and gender.
Increasing flexibility increases physical efficiency and performance. It decreases susceptibility to injury. It helps improve circulation of blood to different parts of the body. It reduces lower back problems and enhances nerve/muscle impulse coordination and velocity. Finally, stretching makes exercising more enjoyable.
Flexibility improves through various ways. Foremost among them are Proprioceptive Neuromuscular Facilitation (PNF), Static Stretching, Strength Training, Isometric Stretching, Forced Relaxation, Yoga and Ballistic stretching.
By far, the best way to stretch is by PNF. In this mode, the muscles are stretched little by little until they reach the maximum stretch ability and then the time of holding them there is gradually increased.
The best time to increase flexibility is to do it after warming up for at least 10 to 20 minutes. It is done between strength training. One must never stretch if injured as this can worsen things.
To increase flexibility, keep the following tips in mind. Daily stretching can produce the best results. For longer lasting results, one should stretch at a low intensity, for a longer duration. In other words, one should hold one’s stretches, to just to a point where one feels a "pull" but not pain, and then hold it for 15-60 seconds. The warmer one’s muscles are, the greater one’s potential range of motion, so one must warm up before stretching by walking briskly for a few minutes, or by doing the majority of deep stretching after one’s cardiovascular workout. It is important to take time to stretch each major muscle group/joint. Proper body positioning is critical for an effective stretch. One must follow the instructions for each stretch.