One of the things that a large majority of our new clients will say they would like as a result of starting a training program (outside of losing weight) is to improve their flexibility. One of the biggest flexibility issues we see is limited hip and spinal flexion (often considered “tight hamstrings”). The old school method of tending to limited flexibility (or tight muscles) was to do some form of static stretching, which is where you basically put your joint (for example we will use the hip joint and the motion of hip flexion, which one would feel tightness in the hamstrings) to the point where you can’t move any more (like a hamstring stretch where you would put your leg up on something and lean forward) and hold that for about 20-30 seconds–until you felt a release or relaxing of the muscle. Go to any 5K race on any weekend and you will see legions of runners preparing for their race by doing static stretching like this. What most people don’t know is there is enough evidence that shows traditional static stretching can actually have a negative effect on your body (joints and muscles) and doesn’t do anything to help prepare you for your activity. In fact, recent research has shown that stretching before an activity, like running or working out, actually reduces your force output. The reason for this is in order to get your muscle to release they have to actually be shut down neurologically (reduce neurological flow) so it doesn’t contract like it did when it was trying to stop you from moving into a greater range.
The thing one must consider is that the brain is getting sensory information from all over the body and constructs movement patterns (muscle involvement for intended movements) based on information coming from your sensors (those in the muscles as well as in and around the joints). If your brain/nervous system senses instability in a joint or joint motion because there is lack of sensory input coming from the sensors in a muscle or group of muscles it will put the brakes on that movement so you don’t move into an unstable range—keeping you from going into a motion which you can’t control. So when I say “muscle tightness isn’t really a bad thing” it’s because your nervous is creating that tightness to protect you from movement(s) you can’t control. Everything the body does is done in our favor or is done based on the information/feedback the body (and its sensors) is giving. It might not be ideal to have limited range of motion but rather looking at the limitation as a problem, we must start to look at it as feedback or information from a very smart system.
So what is the tightness trying to tell us? I like to think of it like an engine indicator light coming on in your car. You wouldn’t cover up the light on the dash because it was an annoyance would you? You would probably take it to your mechanic to allow him to do some diagnostics to figure out why the light (signal) was on. You wouldn’t shoot the messenger, you would simply use the signal to ask more questions (or find someone who could ask those questions to find out what might be wrong). The same thing happens in the body. When we have muscle tightness it is an indicator (a signal) of something else: instability. The instability is caused by muscles not being able to contract to their fullest ability along with not being able to communicate any further with the nervous system. And this instability is noticed when moving in the direction of the limitation. Meaning, if your hamstrings are tight when you bend at your hip it is usually because of instability moving into hip flexion. In this case, your hamstrings would be protecting you from going further into a hip flexed position because some or all of the hip flexor muscles could not contract as well as they should when getting into shorter ranges of motion. When a muscle loses or reduces its ability to send or receive sensory information to or from the nervous system the opposing muscles become protective and contracts. So when you are doing a static stretch what you are actually feeling as “the stretch” is actually a contraction (oh, and I should ad that muscles don’t really “stretch,” and you wouldn’t want them too either—think of a rubber band that you stretched enough to change its length. It doesn’t have the same contractile ability after that does it?). It is the muscle contracting, trying to fight the position of instability. What happens when you hold that long enough is you override the nervous system’s need to protect and you win by “shutting the muscle down” (reducing neurological flow to those muscles). This allows you to get more motion but chances are you not only now have more motion that you can’t control but you also have an opposing muscle group that is less active and functional.
This is why researchers are finding static stretching less and less beneficial for the purpose of preparing the body for exercise or activity. It’s not to say that stretching doesn’t feel good—just as a glass of wine may feel good—it’s just not that beneficial to do as a way to prepare for doing a physical activity that requires movement with some force production (however, what you do when relaxing or trying to relax is your call—wine, stretching ,etc.—have at it!). In my next post I will provide some strategies to help correct some common inflexibility issues as well as cover some ways to properly prepare for physical activity. In the meantime, the best way to think about preparing for any activity you do is to start with some light, slow movements that replicate the movements you are going to do in your activity and build up from there with bigger and maybe faster movements (faster is relative to the speed in which you will be doing your activity). By the way, if you are going to be sitting in a static position or relaxing then static stretching may be the perfect way to prepare. Otherwise, it’s not doing you much good to use it before your physical activities. For more blog posts go to http://fitness-werks.com/blog/