Updated: Aug 2, 2019
Stretching, to some, are often overlooked, however, this is the most important thing to do after a workout to prevent further injuries or muscle soreness.
During exercise, the muscle are expand and contract through tension... post-exercise, muscles stay tight and rigid because of all the stress they've been through, which then causes lactic acid build-up throughout. Ever notice yourself cramping towards the end of a long or tough session? That's because too much lactic acid has been built-up within your muscles and then they are naturally trying to release the toxins via intense contractions.
Stretching allows muscles to release some lactic acid and intake oxygen. Thus reducing or even preventing soreness the following days and allowing those muscles to recover at an enhanced rate. You'll start to notice the difference after a few post-workout stretching sessions, that your DOMS are vastly reduced.
Try to only stretch those muscles you've just trained, otherwise you risk injury. Don't overstretch, be gentle and try to hold the positions for 20-30 seconds.