The old presumption that holding a stretch for 20 to 30 seconds — known as static stretching — primes muscles for a workout is dead wrong. It actually weakens them.The new wisdom has two parts. First a warm-up:
A well-designed warm-up starts by increasing body heat and blood flow. Warm muscles and dilated blood vessels pull oxygen from the bloodstream more efficiently and use stored muscle fuel more effectively. They also withstand loads better ... Most experts advise starting your warm-up jog at about 40 percent of your maximum heart rate (a very easy pace) and progressing to about 60 percent.Second, dynamic stretching tailored to your sport:
Stretching muscles while moving, on the other hand, a technique known as dynamic stretching or dynamic warm-ups, increases power, flexibility and range of motion. ...Some examples of dynamic stretching include the straight-leg march, the scorpion, and handwalking. This video also shows the Spiderman.
Dynamic stretching is at its most effective when it’s relatively sports specific. “You need range-of-motion exercises that activate all of the joints and connective tissue that will be needed for the task ahead,”