You've got your best leggings on [1] and your playlist is lit [2] — you're about to crush your run. What do you do first? You warm up. You start with a forward fold, maybe do a couple Downward-Facing Dogs, stretch out your tight hamstrings, and finish off by stretching your quads. Now you're ready for your run, right? Wrong. If you've been stretching before your runs (don't worry — a majority of us have been), you're not doing your muscles any favors.
When asked if static stretching [3] (holding moves for more than 10 seconds) should ever be done before a run, Jeff Brannigan, director of programming at Stretch*d in New York City [4], replied, "Please don't!" According to Jeff, "Static positions can be very forceful and are more likely to result in an overstretched muscle." This means that faster mile time [5] you've been training for or that half marathon [6] you've had on your bucket list will have to be postponed. "Prior to exercises, static positions can be counterproductive because they can actually stress the very muscle group that you're trying to stretch," explained Jeff. He said to think of your muscles as a rubber band being stretched over a period of time. At some point, the elasticity will be compromised and the rubber band is useless. This is what happens to your muscles when you do static stretching before exercise.
To warm up before a run or any form of exercise, Jeff said to do dynamic stretching [8] (short repetitions of movements). A few examples of dynamic stretching are: plank walkouts [9], butt kicks [10], high knees [11], and hamstring toe touches [12]. After exercise, Jeff said to cool down by doing dynamic stretching to promote blood flow and "help flush out metabolic waste from the muscles and other byproducts of hard physical activity."