To Stretch, Or Not To Stretch?

Some people do it every day, some people do it just once a week, and some haven’t done it for years.  While this could be true of many activities, today we are talking about stretching.  Most of us probably learned how to stretch way back in our elementary Physical Education classes.  Today, those that still stretch might say it improves performance, prevents injuries and just feels good.  Those that don’t stretch usually admit that they should stretch, but just don’t work it into their routine.

There are also those who say stretching isn’t beneficial.  So somebody has to be wrong, but who is it? Is there any research to support one school of thought or another? YES! Luckily there is plenty of research out there, and the topic of this article is to summarize all of it so you can make your own decision about stretching.   We are going to take a look at several areas of research, namely stretching right before activity, regular stretching, injury prevention and some new exciting research out of Spain.  Let’s begin!

Stretching Right Before Activity

Always stretch before a workout right? Just like we always did since middle school sports! It has to be the right way, correct? As Lee Corso so eloquently states, “Not so fast, my friend!”

What does the research tell us? Well, if you stretch right before you sprint, you become SLOWER1!   If you stretch before you lift weights, you become WEAKER2 and your muscle endurance DECREASES3! Feel like jumping for today’s workout? Do not stretch before as you will DECREASE power, DECREASE jump height, DECREASE jump force and DECREASE jump velocity3!

So what in the world of muscle physiology is going on here? Well, the goal of stretching is to lengthen a muscle.  This is accomplished two ways:  1) by causing small amounts of damage to the muscle and 2) relaxing the muscle.  Both of these cause muscles to be weaker.  Obviously, a weaker muscle is going to be slower in a sprint, under-perform in weight lifting and decrease your jumping abilities.

After reading the previous part, those of you who never stretch are shouting out cheers of vindication while the regular “stretchaholics” are hanging their heads in defeat.  Hold on.  There’s still a lot to be covered.  Let’s start with having a regular stretching routine.

Benefits of Regular Stretching

What happens if we stretch every day?  You might think that if stretching before a workout causes decreased performance, than wouldn’t it make sense that regular stretching would decrease performance even more?  Nope.  In fact, in turns out to be quite the opposite!

Regular stretching (described as stretching a muscle 30-60 seconds every day for 3-4 weeks) has some pretty amazing benefits.  First, you can achieve more flexibility and increased range of motion, which is probably of no surprise.  More impressively however, is that you can INCREASE muscle force and contraction speed, INCREASE jump height, become FASTER in a 50 yd dash, and INCREASE muscle endurance2,4.  To summarize, regular stretching basically produces the OPPOSITE effects of stretching before an activity.  Feeling better stretch addicts?

So some explanation is probably necessary.  The benefits derived from regular stretching are most likely due to stretching-induced hypertrophy.  Yup, your muscles can actually get bigger, faster and stronger by only stretching! Not exactly the same gains as resistance training, but surprising nonetheless!

Stretching For Injury Prevention

We often hear this as a common reason for stretching.  You don’t want to be injured, so you stretch your muscles to prevent injury.  Makes sense, right?  Well, let’s see what the research says.   A review of the evidence came up with the following conclusion: “There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes5.” Basically, we don’t really know if stretching prevents injuries.  The jury is still out on that one.

However, there is one interesting study done by the USA Track & Field association6.  The study took almost 1400 regular runners and placed them into one of two categories: a group that would stretch before running and a group that wouldn’t stretch.  While they reached the conclusion that stretching had no effect on injury prevention, it did show some interesting nuggets of information.  For one, if a runner previously stretched before running, but was placed in the non-stretching group, that runner was actually more likely to receive an injury!  There’s probably some psychological aspect of this, but that’s a topic for a different day.  Also, while stretching or not stretching did not predict injury, several factors DID predict injuries.  Those factors were an increased Body-Mass Index (BMI), increased age, increased weekly mileage, and history of chronic injury or injury within the previous 4 months.

Mindfreak Time!

There’s some new research coming out of Spain that, to say the least, is pretty dang cool.  Let us ask you a question.  If you wanted to improve hamstring flexibility, what would you do? Well, duh, stretch the hamstrings, right? What if I told you there’s another way? Researchers took students and players with the Extremadura Football Club (soccer club for us Americans) and measured hamstring flexibility several different ways7.  They then stretched the sub-occipitals (the muscles on the back of your neck immediately below the base of your skull) and re-measured.  Surprisingly, hamstring flexibility improved significantly!  In a group that underwent a “fake” treatment, no change was reported.

The same school did another study with crazy results8.  They first measured how much pressure it took to cause pain when pushing on the masseters (muscles underneath your “cheek bones” that clench your jaw) and the upper trapezius (muscle that runs from shoulder blade to your neck).  Mouth opening range of motion was also measured.  They then either, A) did nothing, or B) stretched the hamstrings for 40 seconds.   If you stretched the hamstrings, it actually decreased pain sensitivity in those face and neck muscles! Also, the range of motion for mouth opening increased!

So how can stretching one muscle actually relax AND decrease pain in a distant, seemingly unrelated muscle?  In short, all muscles are connected to each other neurologically (through nerves, the spinal cord and the brain).  If we relax a tight muscle, often a signal is sent to other tight muscles telling them to relax as well.  While this is a probably a surprise to many, those of us in the world of manual therapy see it every day.  Relaxing a trigger point in the pectoral (chest) muscles often automatically relaxes a trigger point in the in neck muscles and vice versa.   Research also shows that mobilizing or adjusting joints also relaxes distant muscles without any direct treatment9!

Conclusions

Hopefully you feel far more educated on the topic of stretching.  Let us review some key points:

Don’t stretch before your workout, unless you want to be weak and slow.
Stretch daily (but after or hours before a workout) to improve performance.
If you want to stretch to reduce injury, go ahead.  Don’t want to stretch to prevent injury, go ahead and don’t stretch, because nobody really knows what’s best.

When preventing injury is a priority, then become leaner, younger, only run/bike the appropriate mileage, and don’t have a history of pain (some of those are harder to do than others).

Many times a seemingly tight muscle is often due to a problem somewhere else in the body.  If stretching doesn’t help, it may be time to see a good manual therapist (chiropractor or physical therapist).

That’s it for this article.  As always, if you have any questions, comments or ideas for future articles please contact us!

Drs. Jeff Remsburg and Thomas Cotter are chiropractors at Active Health Solutions: Chiropractic & Rehab, located in Prairie Village, Kansas.  Their clinic focuses on combining cutting edge chiropractic care with the latest in exercise and rehabilitation for pain treatment and performance enhancement.  You can find more information about their clinic by visiting their website at www.activehealthKC.com or by calling 913-341-1200.

References
Journal of Sports Sciences, 2005; 23(5): 449-454.
Clinical Journal of Sport Medicine, 2004; 14(5) 267-273.
Journal of Strength and Conditioning Research, 2005; 19(2): 338-343.
Journal of American College of Sports Medicine, 2007; 39(10): 1825-1831.
Medicine & Science in Sports & Exercise, 2004; 36(3): 371–378.
www.usatf.org/stretchstudy/StretchStudyReport.pdf
Journal of Manipulative and Physiological Therapeutics, 2009; 32(4): 262-269.
Journal of Manipulative and Physiological Therapeutics, 2010; 33(1): 42-47.
Pain, 1996; 68: 69-74.