Tuesday, April 13, 2010

Getting Ready for Activity: Stretching... The Truth

Take yourself back to gym class. you're standing there reaching down and stretching towards your toes, sneaking peacks around the room to see how flexible your peers are, The whistle blows and it is time to start breaking into teams and playing the game of the day. After all, you are all stretched out now, so athletic activity is safe. Or is it?

Unfortunately, the act of stretching statically, which many of us consider common sense for injury prevention, is simply ineffective before athletic performance. Any time we exercise, there is a definite objective, a goal towards which we are striving. When we stretch, the goal is typically to "get loose" or to "warm up" before athletic acivity. Static stretching is the act of stretching a given muscle and holding it for an extended length of time. Contrary to much common belief, this type of stretching is not an effective way to warm up. In fact, static stretching before athletic activity can hinder performance. So why do we still do it?

In the past, it was believed that static stretching allowed muscles to lengthen, thus giving the athlete more range of motion through which he or she could move without risking injury. The latest research however is saying otherwise. Recent research has shown that static stretching will not improve range of motion. It will however allow an athlete to move further through a range of motion without experiencing pain. In exchange for this pain free range of motion, the athlete's performance is negatively effected. While it defies common sense, this claim is easily explained. There are advantages to limiting range of motion in athletics, and there are advantages to experiencing pain when this range of motion is exceeded. I'm going to use a sprinter to further illustrate this example. World class sprinters do not stretch their hamstrings past the range of motion that they use in competition. The reason is preservation of a principle called the elastic component of muscle. The elastic component of muscle defines a given muscle's ability to lengthen and shorten without injury. When we stretch a muscle statically, we reduce its elastic component. Let's go back to our sprinter. The most successful sprinters are the ones who generate the most force between their foot and the ground with each stride (provided the force is generated in the direction opposite of that the runner wants to move). Most of this force is created at the gluteals and the hamstring muscles, as they are the strongest extensor muscles of the leg. Maintaining relatively tight, or short hamstrings ensures that the sprinter's leg will fire into extension with the most force possible.

To understand this principle, picture a rubber band. The tighter you pull a rubber band, the more force is snaps back with. However, if you took that same ru bber band and held it in a stretched position for 30 seconds like we do our muscles, the ability to snap back with any significant force would be greatly reduced. Your body understands this principls; it is one of the reasons pain is experienced when we ask our bodies to work at high levels in expanded ranges of motion. The pain we feel in our muscles is experienced as a protective mechanism.

You might be wondering what you should do before athletics now if you shouldn't be stretching. In my next blog I'll talk about the importance of a proper warm up. Or as I call it, readiness drills.

I look forward to your questions and comments regarding this blog post.


  1. Very interesting, never knew that was the case.

  2. I demonstrate this principle for all of my athlete patients. I want to be clear that I'm not advocating that you discontinue stretching. A proper warm up is very important before exercise, and that does include stretching. The stretches done before activity however should be dynamic, which I'll discuss in my next post. Thank you for your comment Mrsquan.