Many amateur and professional athletes begin and/or end a workout by stretching to improve flexibility. Runners stretch their hamstrings before hitting the road, football players do static stretches as part of a pregame warmup, and yoga practitioners all cool down with stretches after sessions.
 

But does stretching really prevent improve flexibility and boost performance? The answer is: Maybe, but not for the reasons you might think. Also, it depends on the sport in question, the Live Science Website reports. 
 

In some cases, scientists don't fully understand what happens during a stretch.
 

"Yoga will make you more flexible, but we don't know how," said Jules Mitchell, a yoga instructor and a master's degree candidate in exercise science at California State University-Long Beach.
 

It is clear that stretching doesn't actually make muscles longer, but may train the nervous system to tolerate a greater degree of muscle extension without causing pain. During a stretch, the muscle fibers and tendons (which attach the muscles to the bones) elongate, said Markus Tilp, a sports scientist and a biomechanist at the University of Graz, in Austria.
 

Nerve endings are dispersed throughout the muscle and tendon, and if a stretch doesn't feel safe for the muscle, those nerves will fire, registering pain and resistance, Live Science reports.
 

These nerves "will say 'you better stop stretching, because if you stretch further, the muscle will maybe get damaged,'" Tilp said.
 

Jorden Gold, founder of Stretch Zone — a method that employs trained specialists to deliver deep stretching  to prevent injury, improve flexibility, and boost overall health — noted that the limiting factor to achieving full range of motion is “not the length or elasticity of muscles but the nervous control of their tension via the stretch reflex.”         
                                                                                                                                               

He added: “Most of us are thinking about stretching all wrong! Many assume that the static reach-and-hold method is what our muscles, joints, ligaments and tendons need to permanently improve elasticity and increase muscle length. Yet, the latest research indicates that this is far from the best approach to achieve full range of motion and active mobility.”

 

The Stretch Zone technique is based on a different idea, Gold said.

 

“Instead of thinking of stretching as a way to become more ‘flexible’ or ‘elastic,’ it should be utilized as a way to increase your active range of motion and quality of movement,” he said.