Flexibility, Part II: Acute vs. Chronic Stretching
Justin Robinson, MA,RD,CSSD,FAFS,CSCS
Director of Strength & Conditioning - RU Sports Performance Center
Our previous training tip differentiated between static and dynamic stretching. We can further define stretching techniques as either acute (a single session) or chronic (long term – over weeks or months). An acute bout of static stretching will likely NOT increase performance and may actually inhibit performance in explosive sports such as sprinting and weightlifting. Research is less clear, though, as to the effects of acute, static stretching on endurance sports (it probably does not have the same negative effects). Acute stretching also has little effect on injury prevention, although chronic flexibility training will decrease risk of injury and can definitely improve function and sports performance.
As mentioned ("Static vs. Dynamic Stretching") – like rubber bands, the longer we stretch a muscle (up to a point), the farther it will “shoot.” This principle describes why Rehab United Strength Coaches and Physical Therapists emphasize loading and unloading muscles at their optimal length in all planes of motion (sagittal, frontal, transverse). It is also important to note that neural components in the muscle monitor tension and report back to the central nervous system, so stretching strategies should also warm-up the nervous system in a way that prepares the body for how it is about to move. Thus, the optimal method is to incorporate some combination of static and dynamic stretches in your flexibility training to improve ROM over time.
Summary – Fundamentals of Stretching
1) 3-Dimensional: Load the muscles and tendons in three planes (front-to-back, side-to-side, and rotational movements).
2) Sport Specific: Mimic the actions of your sport to produce improved awareness of body positioning (e.g. performing arm circles before swimming).
3) Controlled & Dynamic: Perform each stretch at a speed slow enough to allow the nervous system to relax the muscles, thus, not interfering with the purpose behind the stretch. Increase speed of movement as your warm-up continues to create a seamless transition from your warm-up to your workout.
Click Here for a few handouts with dynamic flexibility exercises: http://www.rehabunited.com/SPC/trainingtips.html