Stretching—Great for Yoga, not Sports, By: Evan Waters

                Nearly every High School training program involves some sort of stretching.  We stretch hamstrings, shoulders, calves; everything that we think will be of use during our activities.  Stretching is even advocated before weightlifting.  Thus, mindlessly many stretch before physical activity because they believe it will increase their athletic ability while decreasing their risk for injury.  Sp much information is available on the promising results from stretching.  Moreover, there is very little information on the NEGATIVE effects of stretching.

Negative Effects

                Let me just say it right off the bat.  If you are a power lifter or lift any weights for that matter, DO NOT STRECTH.  But I feel so much looser after I stretch, many say.  Nonetheless, is there a correlation between stretching and an increase of torque or one-rep strength?  According to many studies stretching is detrimental to one’s ability to exert force through an object such as a 45 pound plate.  The following is conclusive clinical evidence that supports the unpopular theory not stretching.  In a study done in 2003, the Human Performance Laboratory, Wayne State College took ten men and eight women between the ages of 19 and 25 and weight between 134 and 209 pounds.  The purpose of this study was to determine the effect of an acute static stretching bout of the biceps brachii on torque, electromyography (EMG), and mechanomyography (MMG) during concentric isokinetic muscle actions. Maximal Isokinetic forearm flexion strength was tested on two separate occasions.  During this, EMG and MMG were recorded. Subjects were randomly assigned to stretching (STR) or nonstretching (NSTR) before strength testing. Two-way ANOVAs with repeated measures revealed significantly greater torque for the nonstretching group.  The experts at Wayne State College concluded that these results indicate that a greater ability to produce torque without prior stretching is related to the musculotendinous stiffness of the muscle rather than the number of motor units activated. This suggests that performing activities that reduce muscle stiffness (such as stretching), may be detrimental to performance.

                Ok, Ok. It was just a bicep, right?  Still not convinced?  Well, a similarly based study was conducted at the University of Nebraska-Lincoln.  The purpose of their study was somewhat different then the formers in that the University of Nebraska-Lincoln’s study’s purpose was to examine the effects of static stretching on concentric, isokinetic leg extension peak torque (PT) at 60 and 240 degrees, in stretched and unstretched limbs.  The findings suggest that these findings, in conjunction with previous studies, indicated that static stretching impairs maximal force production. They said that strength and conditioning professionals should consider this before incorporating static stretching in pre-performance activities.

                If you are like me, you are probably cringing while finding out this information.  While others, may just shake it off as heresy.  While we’re examining the negative effects of stretching, let’s take a look at the argument that it prevents injuries.  This prospective study was designed to evaluate whether static stretching can prevent training-related injuries in Japanese military recruits. A total of 901 recruits between 1996 and 1998 were divided into two groups. Of which, 518 recruits were assigned to the stretching group and practiced static stretching before and after each physical training session. The control group (383 recruits in the nonstretching group) did not stretch statically prior to exercise. The static stretching consisted of 18 exercises. Injury data from medical records were collected and they assessed the incidence and the location of injury. The total injury rate was almost the same between two groups. Static stretching did not prevent bone or joint injuries. 

While some say that there is not enough evidence to support or cease a routine of stretching before or after exercise to prevent injury among athletes.  Despite the fact that there is a need for more randomized controlled trials, in my opinion, there is sufficient proof that pre-exercise stretching is detrimental in power athletes.