For the millions of people that got all of their fitness advice from a high school gym class, there is one immutable truth. You must stretch before you exercise. The wisdom goes that stretching reduces the risk of injury during exercise. The truth is proving more complicated and elusive.
Range of Motion
Physicians advise patients, particularly as they grow older, to stretch on a regular basis. The reasoning behind this advice is that stretching actually does maintain and increase flexibility, which can improve range of motion. As a lifetime of small injuries adds up, reduced range of motion becomes a serious problem for the middle-aged and elderly. For the young, the goal is to prevent those small injuries in the first place.
While flexibility and a better range of motion, in general, does help to ward off injury during exercise, engaging in some types of stretches right before exercise can work against you. A study published in the Journal of Strength Conditioning Research found that the typical, passive static stretches taught for warming up decrease stability during weight training. Reduced stability can increase the risk of injury. The Scandinavian Journal of Medicine & Science in Sports published a large-scale analysis of 40-plus years of research and the analysis suggests that passive static stretches can reduce muscle strength and power.
PSS versus AD Stretches
It seems the culprit at work is not stretching, but passive static stretching. Both studies offered that a different kind of stretching, active dynamic stretching, doesn’t have the same pitfalls. Passive static stretching is the kind of stretching where a person holds a stretched muscle for 10 seconds to 30 seconds, such as reaching out to touch a toe and holding it. Active dynamic stretching, on the other hand, calls for controlled, ongoing motions that help to warm and loosen muscles. Certain yoga stances, for example, can be adapted to work as dynamic stretching.
Choosing for Results
Neither type of stretching is necessarily good or bad. It all boils down to choosing the right type of stretch for the right activity. If the goal is to warm up for a run or a bit of weight training, active dynamic stretches offer a better route to injury prevention. If the goal is to work on flexibility and range of motion, static passive stretching after a workout or on its own offers an excellent way to work on that goal.
It turns out the old advice from high school gym class holds true. Stretching is good for flexibility, range of motion and injury prevention. The trick is to focus on active dynamic stretching before the workout and save passive static stretching for afterwards.