SCIENCE FRIDAY: STATIC STRETCHING

The rain had ended, morning started to clear. Taken by PKSenagore October 16, 2017. All rights reserved.

​CONFUSING ADVICE ABOUT STRETCHING If you read consistently about running and working out, you’ll be aware that most trainers and coaches who author articles in this area do not recommend static stretching prior to intense running or performance at events.  There’s an almost universal caution NOT to perform passive or active static stretches pre-run or pre-performance. 

​We’re told to reserve them for the post-run cooldown period.  The benefits of warming up with dynamic stretch exercises have been promoted. The usual explanation is that static (sometimes named as ‘passive’) warmup work can hurt and dynamic exercises can enhance performance.
 
All the Earned Runs training plans, which are adapted from respected coaches, have urged runners to perform static stretches after their hard workouts, in addition to foam rolling. Mobility and dynamic stretch exercises are scheduled before runs and races.
 
Recently an article by Aleisha Fetters for MyFitnessPal.com questions whether ANY stretching is beneficial AFTER a run/workout. “The Science Behind Skipping your Post-Workout Stretch” references expert William A. Sands PhD, the lead author of a recently published research review paper in the Strength and Conditioning Journal. Sands recommends a “warm-down” rather than stretching after an intense session of physical activity session to best recover muscle strength.
 
If we are to follow these recommendations, based on scientific studies, will there never be need for static stretching, as opposed to dynamic exercises? Will all trainers and coaches adopt this new thinking?
 
Earned Runs thinks that to try to answer these questions several concepts that are often bundled together should be addressed separately. First, it’s helpful to be clear about the different types of stretching.  Second, the issue of stretch timing after exercise is important. Third, the difference between stretching to improve and maintain flexibility, as opposed to promoting muscle recovery after intense activity, must be recognized.
 
Different types of stretches
Seine Freeman BS, a strength and conditioning expert has provided the very best, although lengthy, article on stretching that I’ve found to date, in a piece, “To Stretch or Not To Stretch” (PDF). It’s been posted on the Earned Runs RESOURCES page since last year. This discussion provides a perfect opportunity to highlight what it offers.
 
“Running and distance walking make your legs strong, toned, and, unfortunately, tight” Freeman says. “After many miles,” your “hardworking muscles and tendons can develop imbalances, scar tissue, and tensions, slowing you down and paving the way for common overuse injuries.”
 
“The goal of stretching” Freeman says, “is to maintain an appropriate range of motion around specific joints,” especially for runners and walkers dedicated to regular, consistent training. With age, the elasticity of soft tissue decreases, so the benefits of stretching are greatest for “mature runners and walkers.”
 
Below is a summary of how Freeman explains the different TYPES of stretches. Much of her exact wording is used and it is NOT the work of Earned Runs; the article is best read in full as intended by the author.
 
*Static: stretching that is done to lengthen/stretch a muscle while the body is at rest, not moving. Slow fluid movements are used to get into the stretched position and this position is held for a period of time (usually at least 30 seconds and sometimes 60 or more seconds)
Active static stretching requires effort from the muscles of the body
            Passive static stretching requires no effort and uses assistance from other sources
           
*Dynamic: stretching that is accomplished as you are moving/in motion. This kind of stretch is not held but activates and loosens muscles and tissue as it takes major joints through a full range of motions.  Starting with gentler and slow repetitive movements, dynamic exercises gradually build to increase range of motion and speed, and are designed to prepare your body for the movements you plan to perform.
 
Stretch timing
Freeman discusses the importance of regular, even daily, static stretches to overall flexibility. Doing so can “address muscle imbalances and asymmetries. Ultimately this will help to prevent overuse, especially if special attention is paid to stretches that reveal more tightness on one side than the other”.  With regard to the topic of timing, she indicates stretching should occur after a warmup period. 
 
There another dimension to stretch timing. WHEN, EXACTLY, IS THE PRE-RUN PERIOD in which the dynamic moves are best? Immediately before, like we see the track athletes doing on the infield or along the sideline of the oval just before their event is called? And WHEN, EXACTLY, IS THE TIME PERIOD IN WHICH PASSIVE STRETCHING IS ‘BAD’? Immediately before, 30 minutes, or an hour before a tough run, workout, or race? And specifically, when is it not a good idea, afterward. 
 
The research review article with lead author Sands, featured by Fetters, does not provide new evidence. It discusses previous research, and includes a sentence that mentions passive static stretching.  There is one reference for the statement “neither hot or cold or stretching for 15 minutes after stairclimbing exercise was effective in recovery with equivalent control and experimental groups up to 72 hours after exercise”. 
 
That 2008 reference, “Effect of Postexercise Recovery Procedures Following Stairclimb Running” looked at 20 club and elite level rowers who performed an exhaustive exercise designed to cause muscle damage. Subjects rested, performed 15 minutes stretching (8 stretches x 2), or went through a hot/cold water immersion protocol immediately after the exercise and at 24, 48 and 72 hours.  Before and at 72 hours after the session of exhaustive stairclimb running, performance tests were administered. Blood levels of an enzyme released by damaged muscle were measured and participants rated muscle soreness after the exercise and at 24, 48, and 72 hours.
 
 The results did not reveal a difference between the 3 types of recovery methods with regard to “significant strength or performance benefits” or alleviation of perceived muscle soreness.  The study did not test the effect of these methods on flexibility, performance, or injury tendency at the same time intervals or much later in the rowing season.  
 
The focus of the research review referenced by Aleisha Fetters is on elite, or near-elite level performance and muscle soreness within 3 days of an exercise designed to cause muscle damage.  The focus of Seine Freeman’s advice on stretching is to help average, everyday runners and walkers prevent overuse injuries related to imbalances and asymmetries.
 
It seems that what is often reported about static stretching in running articles (“don’t do it”) refers to its effects on peak performance relatively soon after a tough workout. The research says it’s no worse than other methods.  On the other hand, general health oriented literature indicates the majority of non-elite athletes would benefit from daily maintenance stretching to stay healthy and avoid injury problem (”do it”).
 
The most judicious course of action seems to be to regularly perform static stretching to remain flexible, as flexibility is a measure of health especially with advancing age and can help keep runners and walkers on the road, doing what they love. The caveat:  don’t time static stretches just before events to enhance performance or after very intense workouts to speed recovery.
 
One last bit of science. A recently published study concluded that collegiate trainers seem to “underuse the current research evidence” on pre- and post- activity static versus dynamic stretching.  It may be that, on the contrary, their practical experience leads them to differentiate between stretching for performance enhancement versus injury prevention in the prescription of stretching exercise type.

Athletes interested in preserving function and enjoying years of problem-free exercise activity might benefit from discriminating between advice to improve performance and that which aims to maintain overall health. 

RUN HAPPY!

 http://blog.myfitnesspal.com/science-behind-skipping-post-workout-stretch
 
journals.lww.com/nsca-scj/Pages/ArticleViewer.aspx?year=2016&issue=12000&article=00002&type=Abstract

https://www.ncbi.nlm.nih.gov/pubmed/19967603

http://www.topendsports.com/medicine/stretches/index.htm
 
http://www.topendsports.com/testing/tests/sit-reach-prt.htm
 
http://journals.lww.com/nsca-jscr/Abstract/2017/09000/Pre__and_Post_Activity_Stretching_Practices_of.1.aspx