Why Stretching May Not Help Before Exercise

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To stretch or not to stretch? The latest understanding of preworkout routines may have you rethinking yours.

Recently, the New York Times summed up the latest evidence suggesting that static stretching — slowly moving muscles until they just start to hurt and holding the stretch briefly — doesn’t prevent injuries, and actually impairs strength and speed in some athletes. According to the Times, two recent studies support limiting stretching before physical activity. The Times reports:

One, a study being published this month in The Journal of Strength and Conditioning Research, concluded that if you stretch before you lift weights, you may find yourself feeling weaker and wobblier than you expect during your workout. Those findings join those of another new study from Croatia, a bogglingly comprehensive reanalysis of data from earlier experiments that was published in The Scandinavian Journal of Medicine and Science in Sports. Together, the studies augment a growing scientific consensus that pre-exercise stretching is generally unnecessary and likely counterproductive.

One of the studies from researchers at the University of Zagreb reviewed 104 studies of people who only practiced static stretching as their warm-up and found that stretching reduced muscle strength by 5.5%. The second study looked at fit men who completed basic squats while lifting barbells either with or without stretching beforehand. Those that stretched lifted 8.3% less weight than those who didn’t.

And these are not the only studies to report the trend. In fact, most physical trainers haven’t recommended long bouts of stretching before workouts for quite some time. Most suggest just a little light and brief stretch beforehand, and spending more time on recovery stretching afterwards. “It has been a long time since anyone has recommended extensive stretching before exercise, because it has been known for a while now that the best time to stretch is after,” says Richard Cotton, the national director of certification at the American College of Sports Medicine (ACSM).

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So why did stretching become such an indelible part of the preworkout routine? It can help with flexibility and improve range of motion, but trainers say many people conflated stretching with warming up muscles. Most people stretch to prime muscles for the workout to come, but there is little evidence that it prevents injuries. “I think stretching is an important part of the physical-fitness regime, but there have been some misconceptions about it. People think that if they stretch before an activity it will prevent injury, but there are no studies to date that show it alone prevents injuries,” says Lynn Millar, a professor of physical therapy at Winston-Salem State University in North Carolina. “If you go back to training guidelines, they say that stretching is part of it, but not all of it. It should not be done alone as a warm-up.”

What makes stretching so potentially harmful to muscles? Cotton believes muscles may actually lose flexibility when they are overworked, somewhat like what happens when you continually stretch a rubber band. “It gets kind of limp. If you overstretch your muscle and then demand a power activity, it makes all the sense in the world that it doesn’t have the power or force that it would if it hadn’t been stretched,” he says.

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Even the ACSM’s Resources for the Personal Trainer manual isn’t much help in resolving the stretching question, since there isn’t much scientific evidence documenting the risks and benefits of flexibility training; most of the advice on the subject, the manual notes, is based on the personal experiences of coaches, physicians and trainers rather than a solid understanding of human anatomy, physiology and biomechanics. “Unfortunately, the existing science of flexibility training often presents fitness professionals with more questions than answers regarding the benefits and risks of stretching,” the manual reads.

Here’s what is known — stretching and flexibility training can give people a wider range of motion in their joints, which can help them to perform their daily activities and improve balance and posture, which are important in preventing falls and other injuries as people age. The risks of stretching include decreased strength, especially in weight-bearing activities.

So when it comes to preparing for a workout, it may make sense to focus on warming up the body rather than simply stretching muscles. That means adding exercises in addition to light stretching, like jumping jacks, which can prepare the body for intensive activity without making the muscles vulnerable to overwork. “If someone is jogging or walking, I recommend a gentle warm-up that takes less than a minute to stretch the quadriceps, hamstrings and calves,” says Cotton. “I feel better when I do that, but I wouldn’t mandate it for every client. There is value in stretching to increase range of motion and enhance activities of daily life.”

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Of course, everyone’s needs and capabilities are different, and the amount and type of stretching should be tailored to the individual. For instance, athletes like swimmers and gymnasts may spend more time doing dynamic stretches, which involve movements that take the body through its entire range of motion. Anyone who is recovering from an injury, in which there may be considerable scar tissue that limits range of motion may also require a bit more stretching to prevent further damage to joints and muscles.

Stretching does have its benefits, say trainers, it’s just a matter of understanding how to incorporate the right amount and type of stretching into the activity you have planned. For most people, that may mean adding more warm-up routines and cutting back from intensive stretching before exercise, but not writing it off completely. “Some people say, ‘Well if it doesn’t prevent injuries [during exercise], why do it?'” says Millar of stretching. “I say, don’t throw the baby out with the bath water. Stretching keeps your normal flexibility, and research shows keeping it part of your routine, either after your workout or later in the day, can prevent injury.”

34 comments
hijabe
hijabe

I quit doing static stretching before exercise years ago.  But, I find dynamic stretching very beneficial before exercise especially before cardiovascular exercise which is a lot different than lifting weights.  I think dynamic stretching is important before functional movement.  

If you think about it, we should look at other species as models for when to stretch.  Dogs and cats both stretch.  When do they stretch?  Any time they go from not moving to some sort of movement.  If they lay down for awhile, the first thing they do when they get up is stretch.  But, they do a very whole body stretch not an isolated static stretch.  They also don't do prolonged stretching.  They do one stretch and then go - so maybe the model for human behavior should be a small amount of dynamic stretching more often in the day.

BuckyFuller
BuckyFuller

I find, as a runner ror 15 years, that I don't do as well and am more prone to injury when I stretch before exercising. I have pulled my right calf muscle three times in the last five years and each time I had stretched before hand. I like to stretch after I run to help my muscles from tightening too much. But that could just be me.

swashbuckler1
swashbuckler1

So should I stretch or not. Seems like the writer did not get to the final answer on this either ?

If stretching my Achilles before a workout might increase the risk of rupture then I need to stop it.

Kain420
Kain420

“Zombieland Rule #18 – Limber Up”

FitnessSpecialist
FitnessSpecialist

This chick is retarded.  No real citations, and no real scientific data.  Shut your fat journalism mouth up and make a sandwich like you know you want to.

Brons
Brons

to mortea: anything that reduces the performace capacity during the workout limits the benefits, assuming the exercise is a strong effort intended to build strength. Warm up, light stretch if you want, build up to max effort, warm down, then stretch/massage/hydrate and fuel the muscles to improve recovery. Periodic hard streching sessions, unaccompanied by hard exercise, can be very beneficial to reduce injury and build muscles over the long term.

Brons
Brons

First, this article is an admonition against Static stretching (holding it) and stretching that approaches the limit of a muscle's extension, before a major effort. This is not new understanding, but is perhaps not well known among weekend warriors. Light stretching, especially active stretching (with light activity in the muscle) may be helpful in gearing up for an effort.  Heavy stretching does at least three things that may limit performance in the short term (but enhance growth and performance longer term). First, it pulls the myofilaments (actin/myosin) to their furthest limits, meaning there is minimal overlap at the start of a contraction cycle. If some elements (a few percent) remain a bit extended from their pre-stretch rest position, then the overall strength of contractions is weakened; especially in a test regime where only a first power lift is recorded. Second, strong stretching typically causes some tearing of the muscle fiber membranes (surface and internal), which limits the excitation/relaxation cycling of the signals (e.g. calcium) that speed and sustain contractions. This damage, in limited amounts, is also a signal that increases muscle growth with exercise, lengthening fibers as well as fattening them (hypertrophy). But in the short term, a little damage weakens the contractions a little bit. It can also lead to more severe damage in extreme workouts. Third, stretching also activates the sensory apparatus in muscles and tendons. These nerves (e.g., spindles, golgi tendon organs) normally directly stimulate muscle contractions, in some cases augmenting or balancing contractions in neighboring groups of fibers to maintain force and length. The activation points for these sensory organs are altered in the wake of stretching. It bears emphasizing that it is not established how each of these mechanisms, and others, contribute to changes in muscle activity after stretching. But, there is clear physiological rationale for why stretching can reduce short term performance, by a few percentage points.

mortea
mortea

I don't get why anyone would care about this.  Does it matter to me if I'm 5% low during a workout?  Is every workout a competition?  The real question is: does it benefit the outcome of working out?  Do the benefits of the workout last longer, take more effect, or less?  This just seems like a bizarre article because it doesn't address that.

samuel.elrod
samuel.elrod

I've always wondered about this as 90% of the time, I've always stretched before working out and running. The more I stretched, the weaker and more "wobbly" I felt....days I didn't stretch at all, I felt my best.....but continued to stretch because it is suppose to be better....

BobjustBob
BobjustBob

I used to teach college stretching and weight training classes in the early 90's.  Couldn't locate research verifying benefits of pre-exercise stretching at that time, but most of my colleagues would reject this notion often arguing that the benefits were so evident that there was no need to resort to studies.  Seems that there are even more now who still "don't need no stinkin' science".

RicardoMontoya
RicardoMontoya

Stretching provides me the flexibility and agility to compete at both handball and racquetball that require during intense plays the body to perform as a strong gladiator and a ballet dancer at nearing 60 years young.Before the games and after each stretch-out I can feel every nerve and blood vessel transferring internal intelligence through-out this body, there-by stretching is no longer a warm-up, but used as an internal operational check-list.

nobotee
nobotee

The most important thing to do in preparation for using your muscles (aka exercise) is to supply them with fresh blood. Fresh blood supplies necessary oxygen and removes free radicals. 

bdwilkin
bdwilkin

When I stretch, my run seem to go easier.  When I don't stretch, my run seems to take more effort.  There is my scientific study.  I will keep my stretching.

NormanChadwick
NormanChadwick

This is not news. I read about this in an ACMS publication years ago.  But many people still follow the stretching ritual prior to excercise because that is what their coach or gym teacher taught them years ago. 

WaxyVernix
WaxyVernix

Columbus: Uh, no. You should actually limber up as well. Especially if we're going down that hill. It is very important.
Tallahassee: I don't believe in it. You ever see a lion limber up before it takes down a gazelle?

WasntMee
WasntMee

Stretching larger muscles is the focus here for strength. Useless.........but you need to stretch the smaller supporting muscle groups that help twist (especially) and bend. If you are a sprinter, the time to stretch is in practice. Otherwise warm up the larger group.

Stretching large muscle groups is for AFTER the workout.


FrankMlinar
FrankMlinar

I use stretching as another exercise. I don't worry about "losing strength" for lifting weights. I notice that I lose strength just by lifting weights. That is, one set of exercise fatigues my muscles  such that I can see a difference in strength when moving to the next set.

Nusurf
Nusurf

Who the hell does your copy-editing??  Truly disappointing.

BrakeFastClub
BrakeFastClub

You better stretch after lifting weights or you will regret it.  You wont be able to straighten your arm eventually.

PGizzle
PGizzle

This study is completely incorrect. A person doesn't  stretch so he or she can be stronger, lift more, or be a better athelete. A person strectches so they don't pull a muscle. simple as that.

  When I was 18 yrs old I didnt have to stretch. Now that I am approaching 35 I have to stretch ..... or so long hammies and quads.

ClaudeGauthier
ClaudeGauthier

Before a workout, you want to 'warm' up your muscles and to do that, you need only to do 5 minutes of cardio.  Then do your workout.  Once you are done, do your warm down and that's where you can do the stretches.

humtake
humtake

Yeah yeah yeah, in 10 years another study will be published about how post-exercise stretching can be harmful.  Heck, I'm surprised they didn't come out and say stretching causes cancer.  Trying to lump everyone's health into one ideal is ridiculous.  If you stretch and work out and feel better than if you don't stretch first, then stretch.  If you don't stretch and feel no difference in your routine, then don't stretch.  Find out what works for YOU.  Personally, if I don't do a full body stretch prior to a workout then I usually end up injured more often.  But I know others who never stretch and are way more in shape than I am.  It all comes down to each individual.  Find your routine and go with it.  Stop trying to find answers in studies and generalizations.

JoshHewett
JoshHewett

@BuckyFuller - Do NOT stretch your achilles! Definitely increasing risk of injury. Instead do dynamic warm up activities and work on strengthening lower leg muscles in balance (calves, tib ant, etc).

swashbuckler1
swashbuckler1

@BuckyFuller Do you have an opinion about specific tendons such as the achilles ? I've been stretching it beforehand based on the assumption that sudden movement would be disruptive and its better to stretch it, but apparently the new consensus is to warm up the entire body. Get the juices flowing so as to say rather than do extensive stretching prior.

CyndyHaggart
CyndyHaggart

I am wondering if ? You were talking to yourself with your comment?

Don't bother to answer me back. I am not looking for answer for you.

nobotee
nobotee

@bdwilkin That's because you don't run to increase muscle strength. You run for cardiovascular efficiency. 

nobotee
nobotee

@WaxyVernix 

Way to oversimplify. How many lions attempt to take down a gazelle immediately after a long rest? None. Lions, like most terrestrial mammal predators, habitually stretch each time they rise after resting. By the time a lion starts to hunt, it has already done some sort of muscle preparation.  

Do you have a dog or a cat? Watch it the next time it gets up after lying for a while. I guarantee you it will stretch.

cleverlyc
cleverlyc

@humtake "stop trying to find answers in studies"

You are kidding, right? Sure, recommendations change, because the knowledge changes, because we STUDY.

BuckyFuller
BuckyFuller

@swashbuckler1 @BuckyFuller  I would definitely agree that warming up before doing any kind of stretch is beneficial, and doing mild, dynamic stretching (range of motion movements and emulation of the movements performed during exercise) can also help. I would NOT, based on experience, statically stretch the Achilles tendon too much. That is usually what has caused me problems with my calf muscle.