Saturday, January 1, 2011

Study: Strength Training Improves Flexibility, Equal To Or Better Than Stretching

Conventional wisdom maintains that stretching improves flexibility and that strength training makes people "muscle bound"--i.e. less flexible.   I have known for years through self-experimentation that this is hogwash, and have often maintained that properly performed strength training improves flexibility on par with stretching. 

Yesterday I learned that a pilot study presented at the American College of Sports Medicine’s 57th Annual Meeting on June 4, 2010 has confirmed my observations.  The report states:

Researchers compared the two techniques’ effect on flexibility of the same muscle/joint complexes in a five-week intervention.
“The results suggest that carefully constructed, full-range resistance training regimens can improve flexibility as well as—or perhaps better than—typical static stretching regimens,” said James R. Whitehead, Ed.D., FACSM, presenting author of the study.
Twenty-five college-age volunteers were randomly assigned to groups performing either resistance training or static stretching. A 12-person control group remained inactive. All were pre-tested on hamstring extension, hip flexion and extension, and shoulder extension flexibility, as well as peak torque of quadriceps and hamstring muscles. The resistance training and stretching programs focused on the same muscle-joint complexes over similar movements and ranges. Post-tests measured flexibility and strength.

The results—which may surprise advocates of stretching to improve flexibility—showed no statistically significant advantage of stretching over resistance training. Resistance training, in fact, produced greater improvements in flexibility in some cases, while also improving strength. [Italics added]

Although this was a "preliminary" study, I have no doubt that the larger study planned will have the same outcome.  Properly performed, strength training can give you strength, flexibility, and cardiovascular fitness as well. 


Anonymous said...

It is good to see some research support for what many of us practioners have know for years. To 'stretch' my muscles for a lunge... I lunge. For a squat - I squat. I have found kettlebell swings far superior for opening up the anterior chest/shoulder complex than static stretching.

What has interested me as I have deseminated this sort of information is the resistance to it... From the general public who feel they 'must' start and finish all strength training with stretching or they will get injured (even when faced with evidence contradicting that). Many also tend to believe that the stretching component (along with the token cardio bit) is the most important component to maintain. Short on time? Well I'll just stretch rather than do 10 minutes of deadlifting.

The other level of resistance to the notion that strength training can increase flexibility (and cardiovascular endurance) comes from the gym instructors, PT's, and coaches themselves. Many will read the research in this area but still go back to a programme of cardio, weights @ 3x10, finished off with stretching. And in my sport of cycling, strength training would be for track sprinters only - a complete waste of time (apparently) for anyone wanting to develop endurance.

Don said...


I know what you mean. Conventional "wisdom" dies hard.

Avishek said...

THis is great, my legs always feel more open after full ROM leg exercises. Are there other benefits to static stretching at all?

john said...

Weightlifters are near the top of all athletes in terms of flexibility. Ivan Chakarov (World Champion in 1993) of Bulgaria said he does no stretching without the bar.

I think mobility is training specific just like other things like "conditioning." Young and old ballet dancers have the same performance/mobility with certain moves, but the older ballet dancers are more flexible in static stretching--because they've been using old and ineffective training methods, ie, static stretching, for a longer time?

Sue said...

What about doing certain stretches say given to you by chiropractor to strengthen back muscles to avoid back injury again. Is it better to just do some strength training to strengthen back muscles rather than the stretches?

Don said...


Numerous studies have shown that static stretching has no demonstrable effect on muscle elasticity, but merely increases "stretch tolerance" i.e. the more you do these things, the more you tolerate the discomfort associated with stretching the muscle. For example:


Not sure static stretching has any special benefits aside from activating the parasympathetic response (systemic relaxation), or in some cases, releasing dysfunctional (excessive) muscle contraction.


After injury, I recommend corrective "stretches" to relax spasmed (hypertonic) muscles and strengthening weak muscles. Most of us have muscle imbalances from habitual use imbalances (due to handedness, posture, or habitual occupations) that make some muscles stronger on left or right sides of body. These imbalances underlie many injuries.

Some people injure their backs due to weak lumbar muscles, some due to weak abdominals, some due to one buttock or hamstring being stronger than the other, sometimes one side of the lumbar erectors is substantially stronger than the other...etc, so I can't say that in every case the remedy is to strengthen the lumbar muscles.

The Healthy Back Institute handbook can help you identify these imbalances and supplies a corrective strengthening program to relieve pain and prevent re-injury.

Sue said...

Thanks for that but I've read some people having issues with the Back Institute in regards to continual billing. I'm not sure if I should just do the exercises chiro gave me - I think it's a list of exercises they give all their patients.

Don said...


I've never had any problem with "continual billing" from HBI, and I don't know how any one could. You pay for the product and they send it to you. You only get the product if you pay first, just like any other business.

In my case, we paid for the materials and they sent them to us. No additional billing. Why would they bill us again, since we paid legitimately upfront? which leads me to imagine that the people who keep getting billed didn't properly pay to begin with.

I have had students and patients do the same with no complaints. We used the program with great benefit.

If you don't think it helps you they have a 1 year, 100% money back guarantee. Who else will give that kind of satisfaction guarantee? Does your chiropractor have such confidence that he gives that kind of guarantee?

Many chiros give out the one-size-fits all exercise routine to all their patients. This only helps on a hit and miss basis, because as I said, not everyone has the same muscle imbalances.

I hope you can find someone who can help you.

Sue said...

Don, I read it here. Not sure how accurate it is:

Something about getting charged monthly for their newsletter. Otherwise I have come across lots of people recommending them. The pain I have ATM is sciatica on the right side. Its a bugger.

Don said...


Um...if they don't want to be billed for the newsletter, maybe they should cancel their subscriptions to the newsletter?

Sue said...

Do you know if there is a pdf of the book?

Don said...


Don't could try an internet search. But you won't get the instructional DVDs that way.

Matt Schoeneberger MS said...

Don, have you seen this paper?

What do you think? It seems in this scenario, strength training merely increased stretch tolerance as well.


Don said...


According to that abstract neither the stretching nor the strengthening methods they used for hamstrings produced increased flexibility but both methods had increase of stretch tolerance:

"The data analysis demonstrated that strengthening in lengthened position changed peak torque angle in the direction of knee extension (p=0.001). No change in flexibility was observed (p=0.449). Both experimental groups showed an increase in stretch tolerance (p=0.001)."

The last two sentences of that abstract:

"The results demonstrated that strengthening in a lengthened position produced a shift of the torque-angle curve, which suggests an increase in muscle length. Conversely, stretching did not produce modification of torque-angle curve and flexibility; its effects appear restricted to increases in stretch tolerance."

It seems to me that they are saying that they produced evidence that the strength training may have increased muscle length (as well as increased stretch tolerance, noted earlier), whereas the effects of the stretching "appear restricted to increases in stretch tolerance."

In any case, perhaps strength and flexibility training had similar results in this study I have posted about by route of both merely increasing stretch tolerance, at least around some joints.