Why flexibility is important for athletic performance

    When you hear a gym bro or anyone in the fitness community refer to range of motion, they are referring to the degree of movement that occurs at a joint. The measure of that degree of movement is flexibility. In less nerdy terms is means the movement is range of motion and the measurement of that movement is flexibility. For the duration of this article Range of Motion will be abbreviated as ROM.

    Flexibility has two sub terms: Static and Dynamic. Static is passive movements that require no voluntary muscle activity. An external force such as gravity, partner (PNF stretching) or a machine does the work. Dynamic flexibility is the available range of motion during a movement; since movement is required then it requires voluntary movement. Movement=dynamic, static=no movement.  

    For athletic performance flexibility is viewed as the range of motion associated with exercise. The bigger or larger range of motion means force is applied over a longer movement. Weight training at its core is weighted stretching. If we are able to increase the "stretch" (ROM) then we can increase the time under tension for that movement or muscle group. Think about a squat. Little ROM limits the depth of the squat thus limiting "gains" a larger ROM increases squat depth thus increasing "gains" 

    In terms of how flexible you should be it depends on sport and activity requirements. Gymnastics requires superior flexibility while bodybuilding requires much less. Flexibility is not direct indicator of athletic performance either (with exceptions. Gymnastics being one). You never saw Tom Brady being crazy flexible and he was moderately successful. Being inflexible and too flexible (Hyper-flexibility) both have detrimental effects on performance. Flexibility should be viewed as a method to increase ROM to better application to a specific sport instead of just being flexable. Keep in mind that some sports such as shot put/discusses and American Football lineman require additional bulk and therefore sacrifice flexibility for increased muscle mass.