Do you stretch when you exercise?

[bernard]

Welcome to The Stretching Trial

Do you stretch when you exercise? Always? Never? (http://stretchingstudy.nokc.no/study-stretching-web/innhold/welcome.faces)

A lot of people stretch before or after exercise. The surprising truth is that we don't actually know if stretching is beneficial.

In The Stretching Trial we aim to answer this question. You may be one of the people who can help us. We are looking for regular, recreational exercisers who can participate in our trial. To join us, you need to meet a few conditions like having an email address and Internet access.

The University of Sydney and the Norwegian Knowledge Centre for the Health Services are running the trial, and we are cooperating with The Health Report on ABC Radio National and NRK Puls on Norwegian TV to tell people about the study. We gratefully acknowledge the support of Puls and the New South Wales Sporting Injuries Commission.

[TexasOrtho]

When I did a lot more teaching at a local university, I used to bring this up to students regarding the actual evidence behind stretching. There is so much conflicting data out there regarding whether it is beneficial, has no effect, or in some cases actually detrimental to performance.

The Journal of Strength and Conditioning with Medicine Science in Sports and Exercise were my go to journals during those discussions. I'll see if I can did up some of those reviews.

Low level of purely anecdotal evidence to follow: I used to be a fairly competitive gymnast and stretching was a big part of what we did. Looking back, I sometimes wonder how much we truly needed to be safe and perform at a high level. To this day I treat a ton of cheerleaders and gymnasts whose coaches swear they need to be more flexibile in spite of having tremendous flexibility already. Makes me wonder.

[Bas]

I think stretching for many of the athletes I have looked after in my career was "habit", "the coach told me", "doesn't everyone stretch", kind of thing. Funny thing: our past national champion 30 classical X-C skier (at 32 years) had NEVER stretched....and had never been injured. The coaches and I had a hard time convincing him to stretch. Now, I would not even try. (I do stretch myself before windsurfing or golf).
I look forward to the results of that study, Bernard.

[mike]

I started to answer the critera questions to participate in the study.
I really wanted to participate but could not answer yes on the last question:o
I can't even remeber when I stretched the last time.
If I remeber it right, the viscoelasticity of the muscles dosen't change after stretching. It seems like it is the nervoussystem that get used to the stimuli.
I question that I think is relevant is: Does a muscle shortens after exercice?

Mike

[TexasOrtho]

A few relevant abstracts:

Magnusson SP, Aagaard P, Nielson JJ.Passive energy return after repeated stretches of the hamstring muscle-tendon unit. Med Sci Sports Exerc. 2000 Jun;32(6):1160-4

It has been shown that five repetitive static stretches of human hamstring muscle, each lasting 90 s and separated by 30 s, altered the passive properties on a short-term basis. However, a total of 7.5 min (5 x 90 s) of stretching for a single muscle group may be an unrealistic stretching program. PURPOSE: The present investigation examined whether three repeated 45-s static stretches had a measurable effect on the passive properties of the hamstring muscle-tendon unit, in vivo. METHODS: Resistance to stretch was defined as the passive moment (Nm) offered by the hamstring muscle group during passive knee extension using a KinCom dynamometer as previously described (Kinetic Communicator, Chattecx Corp., Chattanooga, TN). The static stretch exercise was administered to the left lower extremity of all subjects and consisted of a dynamic phase of passive knee extension to a predetermined final joint angle followed by a 45-s static phase. The procedure was repeated for a total of three 45-s static stretches with 30-s rest period between stretches. RESULTS: There was a significant decline in resistance over the 45-s the static phase in stretch 1 (20 +/- 3%) and stretch 3 (18 +/- 3%), P < 0.001. Further, the absolute or relative decline in resistance over time stretch 1 and 3 were equivalent. The mean resistance in stretch 1 and 3, expressed as the log(e) of time, yielded an equal and highly linear relationship (r2 = 0.96 +/- 0.01); the slope and intercept did not differ. In the dynamic phase of the stretch, the energy of stretch 1 and 3 were similar. CONCLUSIONS: These data suggest that the static stretching protocol used in the present study had no short-term effect on the viscoelastic properties of human hamstring muscle group.

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Magnusson SP Passive properties of human skeletal muscle during stretch maneuvers. A review. Scand J Med Sci Sports. 1998 Apr;8(2):65-77

Despite limited scientific knowledge, stretching of human skeletal muscle to improve flexibility is a widespread practice among athletes. This article reviews recent findings regarding passive properties of the hamstring muscle group during stretch based on a model that was developed which could synchronously and continuously measure passive hamstring resistance and electromyographic activity, while the velocity and angle of stretch was controlled. Resistance to stretch was defined as passive torque (Nm) offered by the hamstring muscle group during passive knee extension using an isokinetic dynamometer with a modified thigh pad. To simulate a clinical static stretch, the knee was passively extended to a pre-determined final position (0.0875 rad/s, dynamic phase) where it remained stationary for 90 s (static phase). Alternatively, the knee was extended to the point of discomfort (stretch tolerance). From the torque-angle curve of the dynamic phase of the static stretch, and in the stretch tolerance protocol, passive energy and stiffness were calculated. Torque decline in the static phase was considered to represent viscoelastic stress relaxation. Using the model, studies were conducted which demonstrated that a single static stretch resulted in a 30% viscoelastic stress relaxation. With repeated stretches muscle stiffness declined, but returned to baseline values within 1 h. Long-term stretching (3 weeks) increased joint range of motion as a result of a change in stretch tolerance rather than in the passive properties. Strength training resulted in increased muscle stiffness, which was unaffected by daily stretching. The effectiveness of different stretching techniques was attributed to a change in stretch tolerance rather than passive properties. Inflexible and older subjects have increased muscle stiffness, but a lower stretch tolerance compared to subjects with normal flexibility and younger subjects, respectively. Although far from all questions regarding the passive properties of humans skeletal muscle have been answered in these studies, the measurement technique permitted some initial important examinations of vicoelastic behavior of human skeletal muscle.

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Nordez A, Cornu C, McNair P.Acute effects of static stretching on passive stiffness of the hamstring muscles calculated using different mathematical models. Clin Biomech (Bristol, Avon). 2006 Aug;21(7):755-60. Epub 2006 May 3.

BACKGROUND: The aim of this study was to assess the effects of static stretching on hamstring passive stiffness calculated using different data reduction methods. METHODS: Subjects performed a maximal range of motion test, five cyclic stretching repetitions and a static stretching intervention that involved five 30-s static stretches. A computerised dynamometer allowed the measurement of torque and range of motion during passive knee extension. Stiffness was then calculated as the slope of the torque-angle relationship fitted using a second-order polynomial, a fourth-order polynomial, and an exponential model. The second-order polynomial and exponential models allowed the calculation of stiffness indices normalized to knee angle and passive torque, respectively. FINDINGS: Prior to static stretching, stiffness levels were significantly different across the models. After stretching, while knee maximal joint range of motion increased, stiffness was shown to decrease. Stiffness decreased more at the extended knee joint angle, and the magnitude of change depended upon the model used. After stretching, the stiffness indices also varied according to the model used to fit data. Thus, the stiffness index normalized to knee angle was found to decrease whereas the stiffness index normalized to passive torque increased after static stretching. INTERPRETATION: Stretching has significant effects on stiffness, but the findings highlight the need to carefully assess the effect of different models when analyzing such data.

[Jon Newman]

I used to be a fairly competitive gymnast and stretching was a big part of what we did.--Rod

Hi Rod,

What was your experience with progressive flexibility, especially after a certain age? We had an orthopedic surgeon that used to be a gymnast and he claimed he never got much more flexible despite continued stretching.

I wonder if there is a significant genetic component that allows some people to respond to stretching with increases in flexibility and others, not so much.

[TexasOrtho]

Hi Rod,
I wonder if there is a significant genetic component that allows some people to respond to stretching with increases in flexibility and others, not so much.

Most of my experiences were when I was young. Not sure why but I always seemed to participate in sports requiring a lot of flexiblity and agility like martial arts and gymnastics.

I have pretty lax joints globally which allowed an easier transition into some of the biomechanically unfriendly positions of events like rings and parallel bars. I had teammates who had to work much harder than me to achieve and maintain their flexiblity, so their must be some genetic component as we all worked very hard on this.

[pht3k]

what i heard/read in the last year is:

-stretching prior sport do not lessen the probability of injury (but warming up is)
-stretching after sport do not lessen the contracture (and it is not lactic acid that cause those contracture; post-activity contracture are present after excentric activity while this is the concentric component that produce lactic acid)
-stretching do decrease strenght/performance in sports (a friend of mine coach of the canadian halterophili team is aware of this... there no one in the international halterophili scene stretching before a contest)
-but stretching might be positive for endurance sports (like marathon) because it raise the viscoelasticity so there is less energy necessary to acheive a certain movement. so even if it lessen the strenght, in the long run it is wining.

even with those affirmations, flexibility is not futile. more the lenght is in a normal range, less you are prone to injury, but it is not necessarly before or after sport the time to do it. stretching should be done daily to gain flexibilty, but i never teach to do stetching when the flexibility is already pretty good.

and btw with those bilat slr stiff patient, i tend to mobilize the dorsal area and have often really good result to help gaining hamstring flexibilty and slr.

[Jono]

I'm going to have to Google 'halterophili" I think.

I usually think of stretching as being 100% neuromodulation- although as such I find it a very useful form of neuromodulation.

[Jono]

Oh... Halterophilie= Weightlifting

[pht3k]

Oh... Halterophilie= Weightlifting

yes that's it! i thought halterophili was used in english too hehe :shade:

[Jon Newman]

This was referenced (by Barrett?) a few years back.

When and whom to stretch (http://www.physsportsmed.com/issues/2005/0305/shrier.htm)

[Erica]

Nice link Jon. I actually stretch my calves everyday, I find that it has helped my running. My calf would seize up on the treadmill sometimes and since I have been more diligent with this, it has not happened. Go figure...
Erica

[Jon Newman]

I enjoy how spontaneous stretching feels and I do it throughout the day.

How do you account for your cramps/no cramps transition (speculating beyond stretching)?

[Jason Silvernail]

There is some evidence that regular stretching might improve the strength gains of a weight training regimen.
My wife just finished her MS in Ex Sci and did this for her thesis - we are both rather ant-stretching generally, but were surprised to find at least some support for it in terms of strength improvement (in groups already strength training) and in terms of some decrease in injury generally. Note this was 'chronic/regular stretching' they were talking about.

On the whole the evidence appears mixed but clearly weighed against concepts like it will reduce injury - esp if done right before an activitiy.

[Erica]

I am not 100% sure for me why the stretching has helped the cramps but it may have something to do with my awareness of that limb while I run. I tend to overanalyze things !:)

I noticed that my foot was slapping on the treadmilll where my right one was not and I tried to make a conscious effort not to do that (like training the brain I guess) and I think that the stretching aided that transition, sort of like a little mediator so to speak!
Erica

[Nick]

I think, once again, we are faced with the issue that the basic terms of investigation have not been defined. The term "recreational exerciser" highlights common confusion as to the objective of exercise.

Wrt stretching, I promote spontaneous movement / stretching / pandiculation / ideomotion, but not the sustained, forced stretch often recommended. I also always remember Barrett's admonition that we must know what kind of materials we are working with. A "tight" muscle needs to be relaxed more than stretched, a "tight" nerve won't tolerate sustained tension, and "tight" connective tissue may or may not respond to sustained, forceful stretch.

[Jon Newman]

I posted a related article on cramping during exercise here (http://www.somasimple.com/forums/showthread.php?p=49184#post49184)

[Nabor Costa]

I am really surprised by this news. I had read something in an article in the magazine of physiotherapy in spain. Another myth taht falls...:eek:

[Gustavo Pacheco de Souza Cruz]

I don't know really, but with me, I think better when I stretch before the running... but, there are a kind of peoples saying that it's better warming before, a quick warming, then you do the aerobic exercise, and then you do the stretch, but this kind of stretch is short!! I think that this stretching must be with the more or less 50% of the ROM.

I'm not sure really...

[matt c]

hi jason, in regards to ur wifes thesis, is it possible to get a copy of this, id be intersted in reading it
thanks
matt

[smikolic]

I'll never forget this experience on my first clinical... didn't know not stretching could lead to problems...

A very built middle aged man (30's) came in with femoral cutaneous nerve distribution burning pain of sudden onset after walking on a stair-stepper thing of some sort (he never went on this thing before by his report).

We asked him about his pain's behavior (constant, worse laying supine and any activities requiring repetative hip flexion on that side). We asked him about his workout habits (Do you ever stretch? for example). We tested his flexibility (positive for short hip flexors and positive increasd pain with active resisted hip flexion).

My CI let me come up with a theory... and I got all exitied when I came up with my first possible diagnostic theory! I thought his iliopsoas was impinging his femoral nerve and he would improve with some gentle stretching and nerve glides..

In a short time his pain went away and normal sensation returned. We had to educate him on the importance of flexibility as well as strength because this guy literally NEVER stretched. I educated him on the proteins in muscles and how they need to overlap correctly to get a good contraction and how they can actually get stronger if muscles are less short (more area to overlap). He liked that idea and went on to stretch (which I recommended doing after he was warmed up, per the research at the time).

So, I guess I am a believer in stretching in certain cases, and it makes sense that a flexible muscle could be a stronger muscle by the orientation of the proteins I guess...

Steph

[JasonE]

I think, once again, we are faced with the issue that the basic terms of investigation have not been defined. The term "recreational exerciser" highlights common confusion as to the objective of exercise.

Wrt stretching, I promote spontaneous movement / stretching / pandiculation / ideomotion, but not the sustained, forced stretch often recommended. I also always remember Barrett's admonition that we must know what kind of materials we are working with. A "tight" muscle needs to be relaxed more than stretched, a "tight" nerve won't tolerate sustained tension, and "tight" connective tissue may or may not respond to sustained, forceful stretch.

I think Nick has hit the nail on the head. Is stretching beneficial? The question is too broad to receive a succinct answer. Instead it begs a series of questions:

What is the problem?
What are we thinking of stretching?
What method(s) of stretching are we considering?
What is the desired outcome?
What is the context in terms of health history, performance needs, strength/flexibility imbalances, etc.?
What time frame are we dealing with?
Will the client be stretching solo or will they need assistance?
... you get the idea.

I use a wide variety of stretching techniques depending on the situation at hand. At other times, I caution against it.

It will be interesting to see what (if any) conclusions are drawn from the results of the new study.