A couple references at the end of this article may help.
http://sportsmedicine.about.com/library/weekly/aa022102a.htm?terms=stretching
"The current research suggests that stretching can decrease pain and
soreness after exercise. However, no evidence supports the theory that
stretching immediately before exercise can prevent overuse or acute
injuries."
"Many people misinterpreted this finding to mean that stretching before
exercise prevents injuries, even though the clinical research suggests
otherwise."
Stretching - What the Research Shows
Dispelling the myths and learning the truth
Recommendations to stretch or not to stretch are full of
misconceptions
and
conflicting
research.
There is
limited
evidence
to sort out
these issues. Stretching has been
promoted for years as an essential part
of a fitness program as a way to
decrease the risk of injury, prevent
soreness and improve performance. But
what does the evidence support?
Research on Stretching
The current research suggests that
stretching can decrease pain and
soreness after exercise. However, no
evidence supports the theory that
stretching immediately before exercise
can prevent overuse or acute injuries.
Warm-up vs. Stretching
Much of this confusion comes from a
misinterpretation of research on
warm-up. These studies found that
warming by itself has no effect on range
of motion, but that when the warm-up is
followed by stretching there is an
increase in range of motion. Many
people misinterpreted this finding to
mean that stretching before exercise
prevents injuries, even though the
clinical research suggests otherwise. A
better interpretation is that warm-up
prevents injury, whereas stretching has
no effect on injury.
If injury prevention is the primary
objective the evidence suggests that
athletes should limit the stretching
before exercise and increase warm-up.
When looking at the effect of stretching
alone on range of motion, a review of
MEDLINE finds that for both the
immediate (an hour) and long-term
(several weeks) improvements in range
of motion one fifteen to thirty second
stretch per muscle group is sufficient for
most people. Some people require
longer duration or more repetitions.
Research also supports the idea that the
optimal duration and frequency for
stretching may vary by muscle group.
The long-term effects of stretching on
range of motion show that after six
weeks, those who stretch for 30
seconds per muscle each day increased
their range of motion much more than
those who stretched 15 seconds per
muscle each day. No additional increase
was seen in the group that stretched for
60 seconds. Another 6 week study
conducted found that one hamstring
stretch of 30 seconds each day
produced the same results as three
stretches of 30 seconds.
These studies support the use of thirty
second stretches as part of general
conditioning to improve range of
motion.
Guidelines for Stretching
To get the most from your stretching,
you need to customize your routine to
fit your needs. One way to do this is to
stretch until you feel slight pulling but no
pain. As you hold the stretch the muscle
will relax. As you feel less tension you
can increase the stretch again until they
feel the same slight pull. Hold this
position until you feel no further
increase.
If you do not seem to gain any range of
motion using the above technique, you
may consider holding the stretch longer
(up to 60 seconds).
What Stretch is Best?
In general, Proprioceptive
Neuromuscular Facilitation (PNF)
stretching has resulted in greater
increases in range of motion compared
with static or ballistic stretching, though
some results have not been statistically
significant.
Static stretches are a bit easier to do
and appear to have good results.
Studies indicate that continuous
stretching without rest may be better
than cyclic stretching (applying a
stretch, relaxing, and reapplying the
stretch), however some research shows
no difference.
Most experts believe ballistic, or
bouncing during a stretch, is dangerous
because the muscle may reflexively
contract if restretched quickly following
a short relaxation period. Such eccentric
contractions are believed to increase
the risk of injury.
In addition to improving range of
motion, stretching is extremely relaxing
and most athletes use stretching
exercises to maintain a balance in body
mechanics. But one of the biggest
benefits of stretching may be something
the research can't quantify: it just feels
good.
References
Bandy WD, Irion JM, Briggler M:
The effect of time and frequency
of static stretching on flexibility
of the hamstring muscles. Phys
Ther 1997;77(10):1090-1096
Bandy WD, Irion JM: The effect
of time on static stretch on the
flexibility of the hamstring
muscles. Phys Ther
1994:74(9):845-852
Beaulieu JE: Developing a
stretching program. Phys
Sportsmed 1981;9(11):59-65
McNair PJ, Stanley SN: Effect of
passive stretching and jogging on
the series elastic muscle stiffness
and range of motion of the ankle
joint. Br J Sports Med
1996;30(4):313-318
Pope RP, Herbert RD, Kirwan JD,
et al: A randomized trial of
preexercise stretching for
prevention of lower-limb injury.
Med Sci Sports Exerc
2000;32(2):271-277
Safran MR, Seaber AV, Garrett
WE Jr: Warm-up and muscular
injury prevention: an update.
Sports Med 1989;8(4):239-249
Shellock FG, Prentice WE:
Warming-up and stretching for
improved physical performance
and prevention of sports-related
injuries. Sports Med
1985;2(4):267-278
Shrier I: Stretching before
exercise does not reduce the risk
of local muscle injury: a critical
review of the clinical and basic
science literature. Clin J Sport
Med 1999;9(4):221-227
Stamford B: Flexibility and
stretching. Phys Sportsmed
1984;12(2):171
Stark SD: Stretching techniques,
in The Stark Reality of
Stretching. Richmond, BC: Stark
Reality Publishing, 1997, pp
73-80
*Wiktorsson-Möller M, Öberg BA,
Ekstrand J, et al: Effects of
warming up, massage, and
stretching on range of motion
and muscle strength in the lower
extremity. Am J Sports Med
1983;11(4):249-252
Ed and Dana Parrot wrote:
Actually, cats (of all sizes including lions) definitely stretch before the
kill - just watch animal planet. Leopards in particular have a crocuhing
style of approaching prey where they are stretching as they wait to pounce.
But unlike many runners, most cats don't belabor the point. Less than 30
seconds worth, often more like 5-10 seconds. Just enough to kind of "check"
that everything's ready to go. Feline nervous systems are far different
than ours, however, and most of the benefits of stretching are undoubtedly
due to nervous system response. So cats are not a good comparison. But the
point is well taken - stretching minimally before the run is good, but any
more than that is a waste (or even damaging in some cases).That said, the article seems to refer only to pre-exercise stretching -
there were absolutely no specifics cited and in that sense the article is
almost useless from a practical standpoint. Stretching AFTER the run has
been proven in study after study (sorry, no sources handy) to aid in msucle
recovery.- Ed Parrot
----- Original Message -----
From: "malmo" <[EMAIL PROTECTED]>
To: "'ghill'" <[EMAIL PROTECTED]>; "'track list'"
<[EMAIL PROTECTED]>
Sent: Thursday, August 29, 2002 5:11 PM
Subject: RE: t-and-f: flying in the face of convention wisdom> Don't blame me on this old wives tale. Ever see a lion stretch before it
> kills something?
>
> The ten percent rule is next.
>
> malmo
>
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of ghill
> Sent: Thursday, August 29, 2002 8:03 PM
> To: track list
> Subject: t-and-f: flying in the face of convention wisdom
>
>
> stretching?
>
> http://my.aol.com/news/news_story.psp?type=1&cat=0200&id=020829190417434
> 79
>
>
>
