Most fitness professionals -- and anyone who's worked out hard, then stretched -- agree that stretch can reduce, if not completely eliminate, muscle stiffness and soreness. A 2011 meta-study published in the Cochrane Database of Systematic Reviews would seem to refute that, warning that stretching doesn't provide "clinically significant" reductions in muscle soreness. But if you read the fine print, you'll see that the researchers did find statistically significant reductions in soreness due to stretching; said reductions just didn't meet their criteria for clinical significance.
But Wait, There's More!
Regular stretching -- and the resulting increases in flexibility -- provide a host of benefits. Stretching increases circulation, can help realign muscle imbalances, increase range of motion, and reduce your risk of ongoing aches and pains due to poor posture or tight muscles. Increased range of motion, in particular, can also help improve your sports performance and reduce your risk of injury.
Not All Stretches Are the Same
Two distinct types of stretching are available to the unaided exerciser: Static stretching, in which you hold a stretch for 10 to 60 seconds, and dynamic stretching -- exercises like arm circles and leg swings that mimic the exercises you're about to do. Although multiple professional organizations have debunked the myth that static stretching before exercise can lead to injury, they also warn that it may lead to decreases in power and performance in some sports. Dynamic stretching before you work out and static stretching after remains the general guideline.