Dynamic Stretching Versus Static Stretching for Runners
By Rick Morris
Things were much less complicated 30 years ago when I was a high school athlete just learning the basics of running. The science of running was just getting started back then and knowledge was somewhat limited. Today there are many dedicated researchers, scientists and coaches that are constantly refining training methods. Stretching and flexibility is one of the fields that have grown more complex in recent years. Here are the basics of dynamic versus static stretching for runners.
Back in my early days the only accepted practice was to participate in static stretching both before and after training runs and races. Static stretches are exercises in which you stretch your muscle using body weight or opposing muscle groups and hold a gentle stretch for 20 to 30 seconds. This type of stretch does a good job of elongating the muscle and increasing both flexibility and range of motion. In the early days it was thought that this type of stretch was necessary to prevent injuries, maintain range of motion and improve performance. Examples of a static stretch are; hamstring stretch, quadriceps stretch, calf stretch and butterfly stretch.
There are actually two different types of static stretches. The most common static stretches are sometimes referred to as static passive stretch (SPS). When you are in a relaxed position and are using your own body weight to hold the stretch you are performing SPS. The other type is a combination of dynamic and active stretching called static dynamic stretch (SDS) in which a static or stationary stretch position is held using the force of an opposing muscle group. For example if you are lying on your back and you pull your straight leg up as far as possible using only your quadriceps muscle without assistance from body weight you are performing an SDS on your hamstrings.
Active Dynamic Stretches (ADS) are true dynamic stretches in which you are moving your muscles through full, exaggerated motions that mimic the motions of running. Examples of ADS are high knees, heel kicks and lunges.
As I mentioned earlier, for years SPS was the only game in town. You always performed SPS both before and after running because it was believed that SPS would prevent injury and improve performance. Today things have changed. The most recent research is proving that chronic SPS does very little to prevent injuries. An investigation conducted by Rob D. Herbert and Michael Gabriel at the University of Sydney found that static stretching before or after running does not provide considerable protection from injury or muscle soreness. There are other recent studies that agree.
Not only does chronic static stretching not provide a lot of injury resistance but it also may decrease your level of performance. A 2007 study by IM Fletcher and R Anness at the University of Lufton in the United Kingdom showed that static passive stretching included in a warm up decreased sprint performance. This is probably due to a decrease in muscle elasticity and reduced muscle activation prior to ground contact time. In simpler terms it is like over stretching a rubber band. Just as an over stretched rubber band loses its ability to return energy, your muscles lose elasticity and their ability to return stored energy. Muscle elasticity is not just important to sprinters. Distance runners depend upon muscle elasticity to maintain or improve their running economy and power.
The Fletcher/Anness study also showed that active dynamic stretching performed as part of a warm up did not adversely affect muscle elasticity or sprint performance and is the more appropriate pre event stretching method. Dynamic stretching has also been shown to be a more effective pre run routine because it increases the blood flow to your muscles, lubricates joints and decreases muscle tightness.
Does this mean you should never perform static stretching? Absolutely not – Static stretching remains an important part of your training routine. Static stretching is still one of the best ways to increase range of motion and maintain flexibility. What has changed is when you should do them. The best routine to follow is to perform dynamic stretching after a cardiovascular warm up run but before your training run or race. Then do your static stretching routine after your run to maintain flexibility.
