Maintaining your flexibility is very important when you are training for any road race or just a recreational runner hitting the pavement. It has been suggested by many fitness professionals that by using static stretching (holding a stretch for a period of time) you will be able to increase the quality of your running stride and decrease the risk of injury. This turns out not to be entirely true because movements like those associated with running or any activity are learned.
Several studies have shown that just stretching tight muscles will not change the way a person moves. When the body performs an activity such as walking or reaching for something the brain does this not by firing off individual muscles separately but by firing off a pre planned movement pattern consisting a rhythmic grouping of muscle contractions. The brain does this because it is extremely efficient and a faster way of coordinating a movement. These groups of pre planned muscle contractions are something that is learned from day one. These movement patterns can be altered and generally are the older we become. Injury or restriction of motion in a joint are two major ways these movement patterns can be altered. If a person suffers a sprained ankle or strained hamstring for example the body will develop compensatory movement patterns in order to decrease the stress placed on the injury. The problem starts when the injury heals and the compensatory movements now becomes the reprogrammed norm of movement for the body. Even if you stretch and stretch the limb that was injured to regain the normal range of motion it won’t carry over to dynamic activities such as running or walking for example. That is because the movement is not a tightness issue but a learned issue. So, the ‘tight’ muscles need the brain to be taught how to fire off the muscles correctly again. This can take some time and like learning any new learned behavior lots of practice before it becomes natural.
Now this is not to say stretching is not important. Stretching is only part of the equation when you are trying to maximize an injury free running program. Just as much time should be put into correcting and reviewing good form and movement patterns as stretching and running. By doing this you will be able to maximize each run and eventually perform at a higher level and decrease the risk of injury dramatically. Start by finding a fitness professional, physical therapist, or athletic trainer that has experience with movement analysis to see how to start refining your movement patterns, decrease your risk of injury, and perform at the best level you can.